Spanish cardiac catheterization in congenital heart diseases registry. First official report from the ACI-SEC and the GTH-SECPCC (2020)

INTRODUCTION

Atrial septal defect (ASD) is the congenital heart disease most frequently diagnosed in adulthood, with the ostium secundum type being the most prevalent (80% of cases). Since the first transcatheter closures of atrial septal defects, advances in both experience and devices have made the transcatheter technique the method of choice for most patients. However, some specific cases, such as ASDs with multiple defects or multi-fenestrated ASDs (mASDs), which account for 10% of all patients with ostium secundum type ASD, continue to pose diagnostic and therapeutic challenges. Furthermore, the available scientific evidence in this subgroup is scarce.1-4

The objective of our study was to analyze and compare the results of the transcatheter closure of mASD vs the transcatheter closure of the remaining patients with ostium secundum type ASD.

METHODS

Study design and population

We conducted a retrospective study that included all cases of transcatheter ASD closure performed in adults older than 18 years at our center from October 2014 through October 2024.

The patients’ demographic, echocardiographic, and hemodynamic data were collected, including a 6-month follow-up following the intervention, assessing residual shunt and echocardiographic parameters such as right ventricular remodeling. This is a retrospective study in which the patients’ informed consent was obtained for the use of their interventional procedure for research purposes. The authors confirm that the interventions were performed in full compliance with the regulations of the Clinical and Ethical Research Committee and the Declaration of Helsinki of the World Medical Association.

Endpoints

The primary endpoint of this study is to analyze the clinical and echocardiographic results of the transcatheter closure of mASDs. Similarly, these results are compared with those obtained after the transcatheter closure of simple (non-multi-fenestrated) ostium secundum type ASDs.

Statistical analysis

Qualitative variables are expressed as percentages and the continuous ones as mean and standard deviation, or as median with interquartile range, depending on whether they follow a normal distribution. For inter-group comparison, the chi-square test or Fisher’s exact test was used for qualitative variables, and the Student’s t-test or the Mann-Whitney U test for continuous variables, as appropriate. The threshold for statistical significance was set at P < .05. Analyses were performed with SPSS software (version 21; IBM Corp, Armonk, NY, United States).

RESULTS

During the study period, a total of 67 transcatheter closures of ostium secundum type ASDs were performed in patients older than 18 years. The patients’ baseline characteristics and ASDs, the procedure, and the results are shown in table 1. The mean age of the population was 52 years, with a predominance of women (65%). The most common indication for ASD closure was dilation of the right ventricular dilatation (88%). In most cases (91%), transcatheter closure was performed with a single device; however, due to anatomical complexity, 5 patients required 2 devices and 1, 3 devices. The combination of transthoracic echocardiography (TTE) and fluoroscopy was the advanced imaging modality selected to guide the procedure in 65% of cases. Four out of all patients had perioperative complications. Three of these complications were due to device embolization, and all recovered uneventfully; 1 patient presented paroxysmal atrial flutter that required pharmacological cardioversion with amiodarone. All patients progressed favorably and were discharged at 24 hours without complications. At follow-up, 82% had no residual shunt, and zero cases of grade ≥ II shunt were found.

Table 1. Baseline characteristics of all patients undergoing transcatheter atrial septal defect closure

Twelve out of all the patients with ASD closure (18%) had ≥ 2 atrial septal defects, whose characteristics are shown in table 2. The patients’ mean age was 42 years, with an equitable sex distribution. Right heart dilatation was the most common reason for closure (83%), with 2 patients presenting with strokes. All patients were in New York Heart Association functional class I-II/IV.

Table 2. Baseline characteristics, procedure, and outcomes of patients undergoing transcatheter closure of multi-fenestrated atrial septal defects

Regarding the echocardiographic study of mASDs, all patients underwent a TEE prior to the procedure. Patients had between 2 (66% of cases) and 4 atrial septal defects. The most common location of the largest defect was anterosuperior (10 patients), and most (92%) had an associated atrial septal aneurysm (defined as a displacement > 10 mm). The sizes of the largest defects and the distance between the defects are shown in table 2. No patient had pulmonary hypertension prior to the procedure.

Regarding the procedure, all cases were guided by transesophageal echocardiography (TEE) and fluoroscopy, and 3 of them by intracoronary ultrasound (ICUS). In most cases, a single closure device was used (66% of patients); however, in 4 cases, 2 devices were needed, which were implanted during the same procedure (simultaneous implantation). The most widely used devices were the Amplatzer Septal Occluder (AGA Medical, United States) and the Amplatzer Cribriform (AGA Medical, United States). In one procedure, the Figulla Flex device (FFO, Occlutech GmbH, Germany) was used, and in another, the Occlutech device (Occlutech International AB, Sweden). Figure 1 shows one of the procedures that required 2 devices and was fluoroscopy-, TEE-, and ICUS-guided.

Figure 1. A: fluoroscopic image of the closure of a multi-fenestrated atrial septal defect with 2 devices guided by fluoroscopy, transesophageal echocardiography, and intracoronary ultrasound. B: transesophageal echocardiography, mid-esophageal plane, showing the 2 implanted closure devices.

Transcatheter closure was successful in all patients with mASD, without intraoperative complications. Transthoracic echocardiography (TTE) was performed 24 hours after closure and, then, 6 months later. Acetylsalicylic acid monotherapy was prescribed at discharge and maintained for 3 months, except for the 2 patients who had a stroke.

At 6 months, 75% showed no residual shunt, while the remaining 25% showed a grade 1 shunt (minimal, without hemodynamic consequences). Most patients with right ventricular dilatation, (8 out of 9 patients) showed a reduction in the baseline right ventricular end-diastolic diameter after the procedure. There were no strokes at the follow-up.

Table 3 compares the characteristics and results of transcatheter closure in patients with a single ASD and with mASD. In our cohort, patients with mASD were significantly younger (42 vs 54 years; P = .011), with no statistically significant differences in sex distribution (50% vs 69%; P = .207). The mASD group had smaller defects (8 mm vs 16 mm in the single ASD group) and a higher prevalence of atrial septal aneurysm (91% vs 27%). In both groups, the most frequent indication for closure was right heart dilatation. No differences were observed in the choice of imaging modality during the procedure or in the mean size of the implanted device. However, patients with mASD more frequently required > 1 device (single device in 66% vs 96% in the single ASD group). There were no inter-group differences regarding complications or the presence of residual shunt during follow-up.

Table 3. Comparison of patients with transcatheter closure of single vs multi-fenestrated atrial septal defect

DISCUSSION

Transcatheter closure of ostium secundum ASD has become a safe and effective alternative in adult patients. Our study analyzed the results of transcatheter ASD closure in patients older than 18 years, highlighting the differences between single ASD and mASD.

At our center, transcatheter closure has proven to be safe and effective in patients with mASD. The results obtained indicate a high success rate associated with the procedure, with the absence of significant intraoperative complications and a good short- and mid-term safety profile.

A relevant finding is that patients with mASD were significantly younger than those with a single ASD, which could be explained by the earlier detection of these defects due to more evident symptoms, or by the presence of atrial septal aneurysm, which in our cohort was significantly more frequent in the mASD group. This data is consistent with the literature, which describes a strong association between atrial septal aneurysm and the presence of multiple defects.5

As expected, the use of multiple devices was more common in the mASD group than in the single ASD group. Although most cases were treated with a single device in patients with mASD, a considerable percentage (40%) required additional devices due to greater anatomical complexity. This finding highlights the importance of a thorough preoperative planning and the need to guide the intervention with TEE or ICUS. Although the TEE provides a wider field of view, the ICUS is particularly useful in certain situations, as it allows for a more precise visualization of the posteroinferior border of the atrial septum.6

The described complications associated with transcatheter ASD closure include arrhythmias, atrioventricular block, and device erosion. Device embolization is usually a consequence of inadequate size or incorrect placement, and its incidence rate is < 1%. In our cohort of patients, complications were a rare finding, with only 3 cases of device embolization and 1 of supraventricular arrhythmia being reported. In the literature, there are doubts on whether these complications are more common when implanting multiple devices; however, in our patients with mASD, 40% of whom needed > 1 device, no complications were observed.7

Most patients with mASD showed complete closure of the defect at 6 months (75%), and the remaining 25% had a minimal shunt without hemodynamic consequences. A high percentage of patients with right heart dilatation showed favorable right ventricular remodeling. Furthermore, the absence of strokes during the observation period indicates the effectiveness of the procedure in terms of secondary prevention in this subgroup of patients.

Limitations

Among the limitations of our study, the following stand out: first, those inherent to its observational and retrospective design, in addition to being single-centered. Furthermore, the number of patients with mASD is relatively small (n = 12), which reduces statistical power. The absence of a control group of patients with mASD treated conservatively or with surgical closure prevents direct comparisons on the relative benefits of each strategy. Prospective studies with a larger sample size and prolonged follow-up will be necessary to confirm our findings and optimize the management of these patients.

CONCLUSIONS

Although the transcatheter closure of mASD is a solid therapeutic option in selected patients, with results comparable to those observed in patients with a single ASD, the need for prospective and multicenter studies remains to confirm these findings and optimize the therapeutic strategy in this group of patients.

FUNDING

None declared.

ETHICAL CONSIDERATIONS

Informed consent was obtained from all patients for the use of their interventional procedure for research purposes. The authors confirm that procedures were performed in full compliance of the regulations of the Clinical and Ethical Research Committee, and of the Helsinki Declaration of the World Medical Association. The authors confirm that sex and gender variables have been taken into consideration according to the SAGER guidelines.

STATEMENT ON THE USE OF ARTIFICIAL INTELLIGENCE

Artificial intelligence has not been used for the development of this work.

AUTHORS’ CONTRIBUTIONS

L. Cerdán Ferreira and M. López Ramón contributed to data collection. L. Cerdán Ferreira performed the statistical analysis. G. Fuertes Ferre, J. Sánchez-Rubio Lezcano, and M. López Ramón contributed to result interpretation. L. Cerdán Ferreira and G. Fuertes Ferre wrote the article, which was later reviewed by G. Fuertes Ferre, J. Sánchez-Rubio Lezcano, and M. López Ramón.

CONFLICTS OF INTEREST

None declared.

REFERENCES

INTRODUCTION

The collaborative effort between the Interventional Cardiology Association of the Spanish Society of Cardiology (ACI-SEC) and the Interventional Working Group of the Spanish Society of Pediatric Cardiology (GTH-SECPCC), which was initiated in 2019, allowed the reactivation of a Spanish registry of cardiac catheterizations and interventional cardiology in patients with congenital heart diseases. The results of this collaboration have been published in the first 2 reports of the activity conducted from 2020 to 2021.1,2 The main weakness highlighted in both reports is the inadequate estimation of interventional procedures performed in patients older than 18 years. Despite being highly representative of pediatric activity, the number of participating centers, did not seem sufficient to accurately reflect the activity carried out in adult congenital heart diseases in Spain.3,4

This article analyzes the current report, focusing on the activity conducted in 2022, and aims to consolidate the objective of reliably measuring the scope of interventional procedures to treat congenital heart diseases in all age groups. The results of this report were made public at the XXXIV ACI-SEC Congress held in Santander, Spain on June 7th, 2022.

METHODS

The data presented come from a retrospective, voluntary, unaudited, and annually updated registry. This year, a substantial and coordinated change has been made to the section on interventional procedures for the treatment of congenital heart diseases of the ACI-SEC Spanish Registry of Cardiac Catheterization and Interventional Cardiology to standardize data from the 2 registries and facilitate their incorporation into the study of its interventional activity in patients older than 18 years.5

All hospitals already participating in the ACI-SEC Spanish Registry of Cardiac Catheterization and Interventional Cardiology were invited to participate, as well as all pediatric hospitals represented in the GTH-SECPCC. Data were collected by the investigator of each participating hospital through the official website of the ACI-SEC.6

The registry results were managed and cleaned by an external company (Tride, Madrid, Spain), and were subsequently reviewed and compared with those obtained in previous years by members of the GTH-SECPCC and the ACI-SEC board. If the data were discordant, the center in question was contacted for clarification and error minimization.

Due to the methodological characteristics of the study and the fact that it was purely an activity registry, there was no requirement for approval from an ethics committee or processing of informed consent forms.

RESULTS

Resources and infrastructure

Twenty-two hospitals participated (6 more than in 2021), 19 from the publicly-funded health sector and 3 from the private sector (appendix 1 of the supplementary data). Data on cardiac catheterizations in adult congenital heart diseases from 2022 were provided by another 99 hospitals to the ACI-SEC Spanish Registry of Cardiac Catheterization and Interventional Cardiology of the and were included in the analysis (appendix 2 of the supplementary data).

Thirty-four cath labs with interventional activity for congenital heart diseases were included in the registry, of which 7 (20.8%) are pediatric cardiac cath labs exclusively; 9 of them with biplane image-guided systems and 14 with the possibility of implementing rotational angiography. The median number of monthly days dedicated by each hospital to interventional procedures for congenital heart disease was 6 [3-17] days vs 7 days in 2021. Fifteen (68.1%) of these hospitals have round-the-clock catheterization services, even for pediatric patients.

Data on medical staffing revealed that 67 interventional cardiologists with full-time dedication to the specialty were registered, of which 37 (55.3%) treated adults and 30 (44.7%) pediatric patients.

Diagnostic procedures

A total of 1141 diagnostic studies were reported, representing a 4.3% increase compared with the previous year. Age distribution was as follows: 37 (3.2%) cardiac catheterizations were performed in infants younger than 1 month, 127 (11.1%) in patients aged from 1 month to 1 year, 578 (50.7%) in patients from 1 to 18 years, and 399 (35.5%) in patients older than 18 years.

Sixty cardiac catheterizations (5.4%) were classified as emergency procedures. Regarding morbidity, 7 (0.6%) cases of serious complications were reported: 4 arrhythmias (2 with severe hemodynamic instability and cardiac arrest), 1 vascular event, and 1 cardiac tamponade; there was 1 procedure-related death.

Interventional procedures

The activity reported in this section increased by 61.5% compared with the previous year. In all, 2508 therapeutic catheterizations were reported and grouped into 13 categories with the following age distribution: 3 procedures (0.1%) were performed in the fetal period, 163 (6.4%) in infants younger than 1 month, 208 (8.3%) in patients aged from 1 month to 1 year, 754 (30.1%) in patients aged from 1 to 18 years, and 1380 (55%) in patients older than 18 years, of which 903 were added by incorporating data from the ACI-SEC Spanish Registry of Cardiac Catheterization and Interventional Cardiology of the (table 1 and table 2).

Table 1. Number of interventional procedures and distribution by age groups

Table 2. Number of interventional catheterizations performed in patients older than 18 years and distribution according to the source registry

A total of 148 cardiac catheterizations were classified as urgent (9.7% of all procedures performed with this reported datum). The number of interventional procedures reported by each center was distributed as follows: 5 hospitals (21.7%) reported more than 150 catheterizations, 3 (13%) between 75 and 150 interventions, and 8 (47.1%) less than 75 catheterizations. The overall effectiveness of the various interventional techniques used was 97.6%, with most centers reporting effectiveness of more than 95% (table 3).

Table 3. Summary of reported efficacy of interventional procedures

Percutaneous valvuloplasty procedures

Sixty-seven aortic valvuloplasty procedures were reported to treat congenital aortic stenosis (a 48.9% increase compared with 2021), including 2 fetal valvuloplasty procedures. Forty-two (62.6%) of these procedures were performed in patients older than 1 year, of which 20 (29.9%) were older than 18 years. Previously untreated native valves were dilated in 70% of cases.

In all, 138 pulmonary valvuloplasty procedures were reported, including 1 fetal valvuloplasty, representing a 32.7% increase compared with the previous year. Technical data were reported in 104 cases (85%): 95 (90%) were native valves; 7 (4.8%) were imperforate valves; and in 2 cases (1.9%), the procedure was associated with ductal stenting.

Lastly, there were no cases of mitral valvuloplasty that year.

Percutaneous angioplasty procedures

A total of 135 right ventricular outflow tract dilatations were reported (a 25% increase compared with 2021). Technical and anatomical data were reported for 96 (72.7%) procedures: surgical conduit angioplasty was performed in 62% of procedures and native tract angioplasty in the remaining 38%. Stent implantation was performed in 51% of cases, conventional balloon dilation in 43%, and cutting balloon in 5%.

There were 234 pulmonary branch angioplasty procedures. Technical data were obtained from 205 (87.6%) interventions: proximal branches were dilated in 191 interventions (93.1%) and peripheral arteries (lobar-segmental) in the remaining procedures. Stent implantation was performed in 102 (49.7%) catheterizations, conventional balloon dilation in 98 (47.8%), and cutting balloon dilation in 5 (2.4%).

Of 126 aortic angioplasty procedures, anatomical data were reported for 104 (82.5%) procedures: 70 (67.3%) were reinterventions and 34 (32.6%) were treatments on native aortas. The dilation substrate was the aortic arch/isthmus in all cases except for 1 angioplasty of the ascending aorta. The distribution of the technique used was as follows: conventional balloon angioplasty in 29%, implantation of uncovered stents in 18.5%, implantation of covered stents in 37.9%, and redilatation with a previously implanted stent balloon in 14.5%.

A further 100 catheterizations were reported in the category of “other angioplasty procedures,” representing a decrease in their frequency by 9.1% compared with the previous year. The anatomical substrate of the angioplasty was reported in 73 cases, highlighting patent ductus arteriosus dilation in 25 cases, systemic veins in 16, Fontan conduits in 10, and surgical fistulas in 8. Fifty-five percent of the procedures were associated with stent implantation.

Shunt closure and other occlusive procedures

There were 1135 atrial septal defect closures: 782 (68.8%) came from the incorporation of data from the ACI-SEC Spanish Registry of Cardiac Catheterization and Interventional Cardiology of the same year (table 2). Consequently, the volume of patients older than 18 years who underwent this technique was 83.8% overall. The predominant anatomical substrate of the defect was patent foramen ovale, with 705 (62.1%) cases. A total of 72.1% of atrial septal defects (ASD) were classified as complex, and the remaining ASD as simple. Data on procedure guidance were reported in 348 cases (28.3%): transesophageal echocardiography was used in 80.4%, intracardiac echocardiography in 12.6%, and angiographic measurements with balloon in 6.8%.

Patent ductus arteriosus closure accounted for 262 catheterizations. More than half of all procedures (56.1%) were performed in patients aged 1 to 18 years, while 9.2% were performed in premature infants (24 cases). The route of choice was antegrade venous access in 70% of closures. Occlusive devices were used in 88.4% of cases and controlled-release coil devices in the remainder.

Thirty-eight catheterizations for ventricular septal defect (VSD) closures were reported, increasing their frequency by 40.7% compared with the previous year. Data on the anatomical substrate of the VSD were reported in 28 (73.6%) cases, with the following distribution: 20 (71.4%) perimembranous, 6 (21.4%) muscular, and 2 (7.1%) postoperative. Occlusive devices were used in 89.2% of cases and coil-type occluders in the remainder. Two devices were implanted via a hybrid approach and the remaining devices via transcatheter access (93.3%).

Ninety-one catheterizations fell within the category “various occlusive procedures”. Data on the type of occlusion were reported in 65 (71.4%) cases, with closure of systemic-to-pulmonary collateral vessels in 40 (61.5%) cases, venous collaterals in 13 (20%), coronary fistulas in 3 (4.6%), and Fontan fenestrations in 2 (3%). The most widely used material was coil-type occluders (38.8%), followed by occlusive devices (36.1%), and particles as the only material or in combination with others (25%).

Atrial septostomy

Seventy-two atrial septostomy procedures were reported (a 33.3% increase compared with the previous year). Echocardiography was used for imaging guidance in 22.5% of cases, fluoroscopy in 28%, and a combination of the 2 imaging modalities in 49.2%. Forty-nine (68%) interventions were balloon atrial septoplasty procedures (Rashkind). There were also 7 procedures with radiofrequency-guided septal perforation, 7 with needle perforation, and 15 with septal stent implantation.

Percutaneous valve implantations

Eighty-seven procedures were reported, of which 51 (58.6%) were performed in patients older than 18 years. The hybrid approach was used in 2 cases, while the fully percutaneous approach was used in the remaining cases. The pulmonary position was predominant (96.5%), with 2 successful valve implantations being performed in the tricuspid position and 1 in the mitral position. The anatomical substrate of implantation in the pulmonary position had the following distribution: 33 in the surgical conduit, 31 in the native tract, followed by 20 valve-in-valve procedures.

Complications

Morbidity and mortality data were reported for 2401 interventional procedures, with 35 serious adverse events (table 4), including 6 deaths, which translated into a rate of major complication of 1.4% and a mortality rate of 0.2%. The categories associated with higher morbidity rates were percutaneous valve implantation (8%), other angioplasty procedures (6%), and VSD closure (5.2%). The most common complications were device embolizations (8 cases): 4 in ASD closures, 2 in patent ductus arteriosus closures, and 2 stents implanted in the setting of pulmonary angioplasty procedures; surgical removal of the embolized valve was required in only 1 case of ASD closure. Less frequent were vascular complications (6 cases), 3 of them being associated with pulmonary angioplasty procedures. There were 4 cases of severe arrhythmias, including 2 cases of cardiac arrest requiring bailout extracorporeal membrane oxygenation.

Table 4. Distribution of major complications and reported deaths in various interventional procedures

DISCUSSION

To date, one of the main weaknesses of this registry has been its limitations in adequately assessing the interventional activity carried out in the context of adult congenital heart disease. For this reason, and as the most significant novel addition to this report, we included data from 99 hospitals reporting their activities in adult congenital heart disease to the 2022 Spanish Registry of Cardiac Catheterization and Interventional Cardiology in the analysis of the various interventional categories. This has resulted in a significant increase in catheterization volume, totaling 3649 procedures (1002 more than in 2021). Their comparison with the activity conducted in previous years and the significant increase in registered procedures should be analyzed considering this methodological difference, and taking into account the increase in participating centers, 6 more than in 2021 (figure 1).

Figure 1. Comparison of the number of interventional procedures performed in 2020, 2021, and 2022.

The total number of registered interventional procedures was 2508, with notable increases in techniques such as ASD closure, aortic and pulmonary valvuloplasty, atrial septostomy, and VSD closure. A total of 55% of cardiac catheterizations were performed in patients older than 18 years (compared with 32% in 2021), demonstrating an improvement in the representation of interventional procedures for adult congenital heart diseases. Once again, in the pediatric setting, we noted that fetal interventional activity in Spain is very limited, with only 3 reported cases (2 aortic valvuloplasty procedures and 1 pulmonary valvuloplasty procedure), despite evidence of its value and effectiveness in these and other prenatal scenarios, such as pulmonary atresia with intact ventricular septum and hypoplastic left heart syndrome.7

The reported data on the effectiveness of various interventional techniques yielded an overall success rate of 97.6% (compared with 95% in 2021) and a mortality rate of 0.2% (the same as in 2021), with 6 procedure-related deaths. These results are consistent with those reported from most international studies to date.8,9 The rate of serious adverse events of 1.4% is the lowest reported so far (2% in 2020 and 2.7% in 2022), with a decrease in the frequency of all types of complications reported. Device embolizations continue to account for the highest number of cases, amounting to 22.5% overall, followed by vascular complications (20% overall).

The volume of valvuloplasty procedures has significantly increased with respect to 2021: a 48.9% increase in aortic valvuloplasty and a 32.7% increase in pulmonary valvuloplasty. For the first time, most cases involving one of these 2 techniques involved patients older than 1 year. In aortic valvuloplasty, the rate of serious events (6.5%) decreased compared with the previous year (11.1%), although with 1 associated death. The report shows that pulmonary valvuloplasty has become established as one of the techniques with the best results, with a 99.2% efficacy rate and a 1.8% complication rate. These data support the value of pulmonary valvuloplasty as the technique of choice in congenital pulmonary valve stenosis in our setting. However, its mid- and long-term outcomes may be influenced by unspecified anatomical and genetic factors.10

Both in pulmonary angioplasty procedures (of native tract or ducts) and pulmonary branch angioplasty procedures, stent implantation has surpassed conventional balloon dilation as the technique of choice, which has again reduced the use of cutting balloons. The most widely performed aortic angioplasty procedures continue to be aortic arch and isthmus dilatation, which are performed in almost all patients; of note, in this context, the increase in covered stent implantation, which, for the first time, has surpassed other dilation techniques. This increase could be explained by the intention to improve the safety of the procedure by reducing damage to the aortic wall in certain scenarios.11 Furthermore, the availability of covered stents with lower implantation profiles has facilitated their use in pediatric patients of increasingly lower weight and younger age.12

ASD closure remained the most widely performed interventional technique in the registry (45.2% of all interventional catheterizations). The inclusion of patent foramen ovale closure as a procedure within this category and its classification as a congenital heart disease may be controversial but can be reevaluated in future reports. Its rarity in the pediatric setting contrasts with its increasing application in adults, confirming the maturity of the technique and the widespread acceptance of the scientific evidence supporting its use.13 Transesophageal echocardiography guidance remains the usual imaging modality for ASD closure; both intracardiac echocardiography and balloon sizing of the defect are infrequent.

A notable finding was the increasing use of patent ductus arteriosus closure in the group of premature newborns (9.4% overall), as well as confirmation of the preference for the transcatheter option over surgery for these pediatric patients in our setting.14 Antegrade venous access and the use of occlusive devices remain widespread procedures in a consolidated technique that has one of the best effectiveness rates in the registry (98.9%).

The reported data on the safety and efficacy of VSD closure show substantial improvement compared with previous reports: the major complication rate decreased from 18% in 2021 to 5.2% in 2022, while the success rate increased from 77.3% in 2021 to 96.7% in 2022. These figures reflect a change in trend, which could be related to the introduction of new closure devices, and the adoption of technical changes facilitating their approach.15-17 All of this would facilitate the widespread use of the procedure, whose frequency has increased significantly by up to 40.7% compared with the previous year. The increase in the number of cases registered in patients older than 18 years was notable, reaching 38% overall (compared with 22% in 2021).

A 16% volume increase and a significant improvement in the reported safety and efficacy data of transcatheter aortic valve implantation were also reported, of which approximately 60% were performed in patients older than 18 years. There was a decrease in the tricuspid position as the anatomical substrate for implantation (from 10 cases in 2021 down to only 2 cases in 2022), at a time when transcatheter aortic valve implantation has reached an unprecedented growth as a structural heart procedure in Spain.5 Access to new valves—especially self-expanding valves—and the continuous publication of scientific evidence endorsing the results of this technique, continue to enhance the expectations of the percutaneous management of patients with right ventricular outflow tract dysfunction in all anatomical scenarios.18,19

Limitations

The characteristics of this registry may be weakened by its retrospective, voluntary, and unaudited design. Expanding the collected data on certain techniques of special interest would help improve its quality and should be considered in future reports.

CONCLUSIONS

The main finding of this report is the significant increase in the number of interventional procedures recorded compared with previous years, which was closely related to the increase in participating centers. There has been significant growth in aortic valvuloplasty, ASD closure, and VSD closure procedures. The data obtained provide a realistic overview of interventional activity in congenital heart diseases in Spain among all age groups. The reported safety and efficacy results demonstrate the consolidation of most techniques in our setting and are consistent with those published in other international studies.

The incorporation of a greater number of centers with interventional activity in congenital heart diseases into the registry will optimize the quality and reliability of the information generated.

FUNDING

None declared.

ETHICAL CONSIDERATIONS

Due to the methodological characteristics of the study and its nature as solely an activity registry, there was no requirement for approval from ethics committees or signing of informed consent forms.

The characteristics of the present work exclude the consideration of possible variables of sex and gender.

STATEMENT ON THE USE OF ARTIFICIAL INTELLIGENCE

No artificial intelligence tools were used in the preparation of this article.

AUTHORS’ CONTRIBUTIONS

All authors contributed substantially to data collection and the critical review of this work. F. Ballesteros Tejerizo and F. Coserría Sánchez wrote the article.

CONFLICTS OF INTEREST

S. Ojeda Pineda is an associate editor of REC: Interventional Cardiology; the journal’s editorial procedure to ensure the impartial processing of the manuscript has been followed. The remaining authors declare no conflicts of interest.

SUPPLEMENTARY DATA

REFERENCES

INTRODUCTION

Currently, transcatheter pulmonary valve implantation is a common procedure in patients with congenital heart disease and dysfunctional right ventricular outflow tract (RVOT).1 Transcatheter balloon-expandable pulmonary valves (Melody by Medtronic Inc., United States, and Sapien by Edwards Lifescience, United States, both with CE marking) have an indication for conduit, native tract, and prosthetic valve implantation.1,3 However, a large number of patients—most with tetralogy of Fallot—who require pulmonary valve implantation are treated with transannular repair or post-commissurotomy pulmonary regurgitation or valvuloplasty for pulmonary valve stenosis. These patients have very pulsatile outflow tracts with larger sizes compared to the ones of current balloon-expandable valves (22 mm and 29 mm for Melody and Edwards, respectively).4 Not even the 32 mm Myval device (Meril Life Sciences Pvt. Ltd., India) without an indication for pulmonary valve implantation would be adequate for the largest RVOTs out there.

Back in April 2022, the self-expanding Venus P-valve (Venus MedTech, China) achieved the CE marking, and became an actual alternative for the largest native tracts.

This is our initial experience with this new transcatheter pulmonary valve at our center and in our country.

METHODS

Valve description

The structure of the Venus-P valve consists of a nitinol stent. Both the leaflets, and the stent coverage are made of porcine pericardium. Nitinol provides the stent with some sort of shape memory so it can adapt to the pulmonary arterial trunk (PAT) without compressing neighboring structures. This valve is available in sizes from 28 mm to 36 mm in diameter with 2 mm increases (figure 1). It can be used with the largest caliber native tracts.5 The Venus P-valve stent has a diabolo-shaped configuration and adds 10 mm to the borders of the central region (figure 1). It is wider in its borders because it has been designed for tubular PAT implantation without distal or pulmonary artery stenosis. Both the central region and the proximal border are covered with porcine pericardium to prevent paravalvular leak. The distal border remains uncovered to avoid occluding the pulmonary arteries (figure 2).6 The stent has radiopaque marks in the distal border of its tubular region and in its proximal border both indicative of the degree of the porcine valve implantation. The valve crimping system on its delivery system is performed under ice water. In these conditions, nitinol becomes softer and can be crimped onto the delivery system (figure 3). The valve is then fixed to the delivery system through 2 small hooks (figure 2). Once the valve has been attached and its size reduced, it is covered with the delivery sheath capsule in such a way that the valve enters the patient fully covered (figure 3 and figure 4) [22-Fr sheaths in 28 mm and 30 mm valves, and 24-Fr sheaths in the largest ones (> 30 mm)]. Once in the pulmonary tree and in the desired location, the delivery sheath capsule will be retracted so the valve can regain its diabolo-shaped configuration when entering blood flow at 36 ºC to 37 °C temperature.

Figure 1. Selection of different valvular sizes with the dimensions of the different parts of the valve. RV, right ventricle.

Figure 2. Image of the Venus P-valve with its typical diabolo-shaped configuration, and coverage of the entire valve leaving both the distal border and the radiopaque markers uncovered.

Figure 3. A: Venus P-valve prior to crimping. B: valve crimping onto the delivery system inside a frozen physiological saline solution with a specific crimping system. C: crimped valve inside the delivery system while covered by a capsule. D: fluoroscopy showing the valve in the delivery system inside the capsule already inserted into the patient’s pulmonary artery.

Procedural description

Cardiac catheterization was performed under general anesthesia while the patient remained intubated and with heparinization at 100 U/kg. Two femoral veins where cannulated, 1 for diagnostic catheterization, cutting, and advance of the valve delivery system, and the other one to perform the follow-up angiography with a pigtail catheter in the RVOT during valve implantation (figure 4). The coronary arteries of all the patients were interrogated through aortograms or selective coronary angiographies with the same 34 mm cutting balloon (Sizing Balloon, AGA Medical Corp., United States) inflated in the RVOT to discard the risk of coronary compression during the procedure (figure 5B). Similarly, the RVOT was cut with the same 34 mm balloon to see if the anatomy was viable and choose the right valve diameter and length. Cutting was considered occlusive when aortic pressure dropped during balloon inflation and the lack of right ventricular (RV) flow to the pulmonary arteries was angiographically confirmed through an intracoronary injection of contrast into the RV during the balloon peak inflation rate (figure 5A).

Figure 4. Valve implantation process. A-D: slow capsule removal so the valve can adapt to the left ventricular outflow tract (LVOT). Angiography monitorization with the pigtail catheter placed in the LVOT. E: final outcomes after valve implantation.

Figure 5. Right ventricular outflow tract cutting with a 34 mm cutting balloon. A: simultaneous angiography in the right ventricle showing the complete occlusion of the RVOT by the balloon that shows a 27 mm notch at stenosis level. B: coronary artery interrogation during cutting balloon inflation without coronary compromise.

Although the imaging modalities performed while planning (computed tomography scan [CT] with or without magnetic resonance imaging (MRI)] inform us on the most appropriate valvular size for each patient, size was picked based on angiography measurements (30° lateral and 30°cranial right anterior oblique), and on the diameter and location of the notch seen in the balloon during occlusive cutting. Balloon cutting allows us to assess the compliance of the PAT, something that is merely suggested on the MRI. Therefore, this is an essential step that should be made before selecting the size of the valve. We select a 2 mm-to-4 mm larger valve compared to the waist of the cutting balloon with a length that should leave the distal border at pulmonary bifurcation level, and the diabolo proximal border at RV level.

The Venus P-valve is implanted without the need for previous stenting to create a landing zone. A Lunderquist high-support guidewire is placed (Cook Medical, Denmark) preferably in the left pulmonary artery. In the presence of stenosis, hypoplasia or unfavorable angle, the guidewire is placed in the right pulmonary artery. The delivery system is advanced through a 65 cm 26-Fr or 24-Fr Dryseal sheath (Gore, W.L. Gore & Associates, Inc., United States) for valves > 30 mm or < 30 mm in diameter, respectively. Once the Dryseal sheath is in position into the selected pulmonary artery, the Venus P-valve delivery system is advanced. Afterwards, the Dryseal sheath is retracted and the correct position of the capsule into the pulmonary artery is verified. Then, the valve is slowly uncovered by withdrawing the capsule (with a clockwise twist of the wheel of the delivery system). As it gradually enters the patient’s bloodstream, the valve regains its normal diabolo-shaped configuration. When its most distal border has been partially adapted to the pulmonary branch, the whole system is then smoothly removed to the PAT and the valve is slowly uncovered while checking—through pigtail catheter injections into the RVOT—that the valve is in position (figure 4). The valve has 2 lines of radiopaque markers to guide implantation. The distal marks that indicate the distal border of the stent tubular region will remain at bifurcation level. The proximal ones should remain at PAT narrowest region or native annulus level (in the location of the notch seen during balloon cutting), thus reducing the risk of embolization. The valve proximal region—10 mm larger than the central one—will remain, in most cases, in the infundibulum of the RV.

Procedure should be performed through a Dryseal sheath to facilitate the maneuverability of the valve delivery system and guarantee safe valve recapture should repositioning be required. The valve can be recaptured until half of its structure has been uncovered.

An aortogram was performed at the end of all procedures (preferably 30° caudal and 20º left anterior oblique) to confirm the lack of coronary artery compression (figure 6).

Figure 6. Final aortogram for coronary artery assessment. Arrows are indicative of the trajectory of the left anterior descending coronary artery.

Patient selection

A previous study through diagnostic catheterization or MRI with or without CT scan was conducted to see whether the anatomy of potentially eligible patients with valve implantation criteria according to the clinical practice guidelines published by the ESC7,8 was ripe for Venus P-valve implantation (figure 7). CT or MRI acquired images were analyzed by Venus Medtech image technicians who video-called our hospital heart team to discuss the convenience of valve implantation and proper valvular size that best suited the patient’s RVOT size. However, the final size was not decided until balloon cutting was used during cardiac catheterization.

Figure 7. Flowchart of patients included in the study.

This first imaging study discarded 5 patients with unsuitable anatomies for this kind of valve: 2 patients with stents and pulmonary artery stenoses, 2 patients with larger RVOTs compared to the sizes recommended for this kind of valve, and 1 patient with pyramid-shaped right ventricular outflow tract.

Study description

This was a prospective study of the first patients treated with Venus P-valve implantation conducted at our center from September 20^th through November 4^th, 2022. These are the very first implantations of this type of valve ever performed in our country.

Inclusion criteria

This study included patients with dysfunctional native RVOTs and an indication for pulmonary valve implantation in whom diagnostic catheterization and cutting test allowed such procedure.

Variables

Demographic and anthropometric data were collected, as well as imaging modality and procedural data to conduct a descriptive analysis of our own experience.

Definitions

Complications were categorized as minor or major. The later were death, potentially life-threatening adverse events, and events requiring surgery (embolization, myocardial perforation, vascular rupture, residual PR, hemolysis, valvular lesion). The former were complications that resolve spontaneously or subside with clinical treatment without potentially fatal outcomes (vascular access problems, fever, neuroapraxias, etc.). Implantation was considered successful in the absence of major complications 24 hours after the procedure.

RESULTS

A total of 8 Venus P-valves were implanted in 8 patients at our center from September 20^th through November 4^th, 2022. The underlying conditions were tetralogy of Fallot (5 patients), pulmonary atresia with ventricular septal defect (1 patient), atrial septal defect with pulmonary stenosis (1 patient), and ventricular septal defect and pulmonary artery banding (1 patient) who required RVOT dilatation in its configuration. All the patients had a transannular patch. Also, all patients had severe pulmonary regurgitation with RV repercussion and PAT dilatation, and were ineligible for transcatheter balloon-expandable valve implantation due to the size of their RVOTs. table 1 shows a overall description of the patients.

Table 1. Overall description of the sample

All patients had dilated PATs as seen on the CT scan or MRI—meaning they were suboptimal candidates for balloon-expandable valve implantation—and tubular PATs without stenoses in, at least, 1 pulmonary artery.

The valves were successfully and uneventfully implanted in all the patients with optimal valvular competence immediately after implantation. A total of 7 implantations were performed via femoral access, and 1 via right jugular vein due to bilateral femoral venous thrombosis. High-support guidewires were placed in the left pulmonary artery (6 cases), and right pulmonary artery (2 cases, 1 due to moderate left pulmonary artery stenosis, and the other one because it was a jugular access). In 7 and 1 cases, respectively, 26-Fr and 24-Fr Dryseal sheaths were used through which implantation occurred. The length of the valves implanted was 25 mm (n = 7) and 30 mm (n = 1).

The median fluoroscopy time was 34 min (interquartile range, 32-37), and the mean radiation dose, 307 mGy/m² (standard deviation, 64.4). We saw an adequate correlation between the CT and MRI measurements of the PAT and the angiography measurements and the cutting balloon.

No severe complications were reported in any of the cases. In 1 case, while the valve was being deployed, 1 of the proximal hooks got trapped in the delivery system due to incomplete removal of the capsule covering the valve. It, however, resolved uneventfully (figure 8). A total of 3 patients had mild thoracic pain 24 hours after implantation not showing elevated troponin levels or ECG abnormalities. Also, 1 patient complained of right scapula pain. One of the patients had common ventricular extrasystole that started right after valve implantation and subsided spontaneously within the next 48 hours not requiring any therapy at discharge. One patient broke a fever 48 hours after implantation without elevation of acute phase reactants.

Figure 8. Arrows indicate, in 2 different projections, that 1 of the attachment hooks is still trapped in the delivery system preventing full valve deployment.

The mean length of stay was 3 days (range 2-4). All patients were discharged on acetylsalicylic acid.

DISCUSSION

Transcatheter pulmonary valve implantation is, currently, a procedure widely performed in the cath labs of congenital coronary care units. Up until now, the valves available—with sizes up to 29 mm—left a significant number of patients without transcatheter therapeutic options available. In some cases, off-label techniques were used (several stents implanted in the PAT to reduce its caliber, stent landing in the left pulmonary artery, etc.) or larger sized balloon-expandable valve implantation with an indication for the aorta (32 mm Myval valve), but not approved for the RVOT.9

Among the main advantages of the Venus P-valve is the possibility or performing one-stage diagnostic catheterizations and valve implantations since previous stenting is not required to create a landing zone (as it was the case with the Melody and Edwards valves in several native tracts). In the most dilated pulmonary arterial trunks (> 24 mm-to-26 mm) one-stage stenting is the gold standard. Then, wait for, at least, 6 weeks until endothelization occurs to minimize the risk of embolization while the valve is being implanted, which requires a second catheterization to implant the valve. Another advantage of the Venus P-valve is how easy it is to use. It is a short procedure with 34 min fluoroscopy times in our cases (shorter to the times reported in our series of native RVOTs and other valves between 40 min and 50 min).

The flexibility of the valve allows PAT adaptation without exerting radial strength on adjacent structures, which is a plus for cases of coronary RVOT-related anatomies.

The short 25 mm valve was used in 7 cases since these patients’ PAT anatomy allowed such length. With longer length, less flexibility for the valve and higher risk of long-term fractures. Up until today, a rate of fractures between 11% and 27% has been reported without associated complications or loss of valvular competence associated with the fractures.5,10

We should pay special attention to the complete removal of the capsule at the end of valve deployment because, if removal is incomplete as it happened with our case (figure 8), hooks can’t be released, and the valve does not get deployed with the corresponding risk of RV embolization.11 To make sure that the system has been released, the hooks should be checked in, at least, 2 different views or projections.6

The diabolo-shaped configuration makes this valve unsuitable for all RVOT anatomies. In cases of distal stenosis at PAT level or at the origin of pulmonary arteries this valve is ill-advised because such stenoses would be limiting the opening of the valve distal border. Regarding this shape—wider in its borders—the onset of transient ventricular extrasystole due to contact with the infundibulum proximal border has been reported. However, to this date, no arrhythmias have ever been reported requiring ablation or cardioversion. In our own experience, only 1 patient had frequent extrasystoles, yet no sustained ventricular arrhythmias were ever reported.

The clinical trial (NCT 02846753) conducted to obtain the CE marking revealed the presence of isolated endocarditis (incidence rate of 1.2%). When long-term follow-up results become available, the actual rates of endocarditis, fractures, and valvular dysfunction will be assessed.

Limitations

The short follow-up of patients is this study main limitation. We’ve been closely monitoring these patients including the use of Holter monitor and imaging modalities (echocardiography, CT scan, and MRI) to properly assess the mid- and long-term evolution of valve implantation. Another limitation is the lack of a control surgical group, which means that comparison can only be made with a historic cohort.

CONCLUSIONS

In conclusion, valve implantation with the new self-expanding Venus P-valve was, in our own preliminary experience, a safe and feasible procedure for valve implantation in very dilated RVOTs with a contraindication for the current balloon-expandable valves with CE marking.

FUNDING

None whatsoever.

AUTHORS’ CONTRIBUTIONS

All the authors contributed to the management and follow-up of the patients, data mining, and approved the manuscript final version for publication. M. Álvarez-Fuente, and M.J. del Cerro designed the study, analyzed data, and drafted the manuscript. HernÁndez, and I. García OrmazÁbal also drafted the manuscript.

CONFLICTS OF INTEREST

None reported.

REFERENCES

INTRODUCTION

Ventricular septal defect (VSD) is one of the most common congenital heart diseases. Its prevalence is 5.3 cases for every 1000 live births.1 It can occur in isolation or as part of a more complex congenital heart disease. Standard therapy is surgical closure with very low morbidity and mortality rates. However, it is no stranger to complications.

Percutaneous closure can be an alternative to surgery in selected anatomies, thus reducing the length of hospital stay, and complications. Both percutaneous and surgical closures have a potential risk of atrioventricular block (AVB)—< 2% for surgical closure, and 0.5% to 6.8% for percutaneous closure.2-5 The high risk of AVB has led to the development of new and more flexible sheaths and devices to close the VSD with less radial strength that minimize the risk of damage to the cardiac conduction system. In this context, the KONAR-MF VSD device occluder (Lifetech, China) was developed. It obtained the CE marking in Europe back in May 2018. It is a low profile, nitinol, self-expanding device with little radial strength and high flexibility in order to adapt to the anatomy of the VSD without exerting any pressure to the adjacent structures. The device is made of 2 discs united at its waist that has a polytetrafluoroethylene membrane. The right disc is simple while the left one has 1 cone attached to it similar the devices that are used to close the ductus arteriosus (figure 1). Each disc has a screw so it can be anchored to the delivery system in such a way that it can be implanted via antegrade (venous) and retrograde (arterial) access. The device comes in several sizes from 5 mm to 14 mm. It is suitable for different VSDs of different sizes, and anatomies (figure 1). The specific sheaths of the delivery system—5-Fr to 7-Fr—are also very flexible, which reduces pressure to the cardiac conduction system during the device implantation maneuvers. Also, it can be implanted through a 7-Fr or 8-Fr guide catheter.

Figure 1. KONAR-MF device (Lifetech, China) with the table of measures available. Data from the device instructions for use.

This is the early experience of 2 Spanish centers using this new device for the closure of VSD.

METHODS

Retrospective review of patients treated with the VSD KONAR-MF occluder device at 2 Spanish centers: Hospital Universitario Ramón y Cajal, Madrid, and Hospital Universitario La Fe, Valencia from February 2020—date of the first implantation procedure in our country—through September 2021. Patients were selected if they had suitable anatomies for percutaneous closure, that is, proper distance to the aortic valve (> 2 mm), lack of posterior prolongation (enough distance to the tricuspid valve), and proportionate size of the devices available. Since this was a short retrospective review, no control group was included.

The patients’ demographic, clinical, and anthropometric data were collected, as well as the echocardiographic anatomy of the defect, the hemodynamic variables of the procedure, and the immediate complications or at the follow-up.

Definitions

Residual shunt was defined as the presence of flow on the color Doppler echocardiography around the device. Flow was categorized into mild (1 mm to 2 mm), moderate (2 mm to 4 mm), or severe (> 4 mm). The presence of flow inside the device was called intradevice shunt and was considered less significant compared to mild shunt.

Complications were categorized as minor or major:

Device implantation was considered successful in the absence of major complications, and severe residual shunt within the next 24 hours.

Description of the procedure

Previous diagnostic cardiac catheterization, and transesophageal echocardiography (TEE) were performed in all the patients. The patients referred for closure had hemodynamic repercussions due to VSD (left ventricular dilatation). Also, the presence of a Qp/Qs ratio ≥ 1.5 was confirmed through a cardiac catheterization performed under general anesthesia while the patient remained intubated.

The size of the device was determined based on the measures of VSD obtained on the TEE, and left ventriculography. The device was 1 mm to 3 mm larger than the defect (figure 2).

Figure 2. Ventricular septal defect (VSD) in a patch in a patient with tetralogy of Fallot. The upper images reveal the presence of the defect both on the transesophageal echocardiography (TEE), and the angiography. The lower images—also from TEE and angiography—reveal the defect being closed after KONAR-MF device implantation (Lifetech, China).

The VSD probing technique, and the device positioning and delivery are not substantially different compared to those used in other device occluders widely discussed in the medical literature.6-9 The interventional procedure was performed under TEE guidance, and the device was released after being properly deployed without severe residual shunt.

Follow-up after closure of ventricular septal defect

Follow-up visits were conducted 1 month, 6 months, and 1 year after closure. After that time, depending on the patient’s baseline condition and clinical situation, follow-up was conducted every 6 or 12 months. Anamnesis, physical examination, electrocardiogram, and echocardiography were performed in these visits. Blood tests were also added to the mix in cases of suspected hemolysis. In the presence of any other symptoms or pathological findings in any of the tests performed, additional studies were conducted like Holter, ergometry or further imaging modalities.

Ethical aspects

In compliance with the current legislation, and since this was a retrospective case review it was not necessary to obtain the patients’ informed consent or approval by the ethics committees of the participant centers.

RESULTS

From February 2020 through June 2021, a total of 7 consecutive procedures of VSD closure were performed at the 2 centers using the KONAR-MF device by successfully implanting this device in 6 out of the 7 patients. Table 1 shows the overall description of the patients. Cases were restrictive defects (native or postoperative) with echocardiographic data of hemodynamic repercussion (left ventricular dilatation) without clinical translation in patients > 8 years.

Table 1. General description of patients treated with percutaneous closure of VSD

The anatomy of VSD was:

The size of the VSD measured on the TEE and angiography was consistent in all the cases except for 1 with a small VSD covered by an aneurysm.

In all the patients, vascular approach was attempted via femoral access (artery and vein); in 6 of them closure was performed via antegrade access, and in 1 patient via retrograde access. Retrograde access was attempted in 1 patient in whom the proper positioning of the right disc could not fully achieved. Finally, closure was successfully completed from the right ventricle, but with longer x-ray image and procedural times. The median x-ray image time was 27 minutes [IQR, 22-50].

There were no immediate complications in any of the cases reported except for 1 embolization in a small VSD with aneurysmal tissue (case #5) where the size of the VSD measured on the TEE and the angiography did not properly correlate. The device embolized to the left pulmonary artery and was retrieved percutaneously through a bailout procedure. The patient was treated with VSD elective surgery a few months later. No hemolysis or vascular complications were reported in the series with a maximum follow-up time of 17 months (median follow-up, 1.2 months; IQR, 0.9-15.5).

Immediate residual shunt was seen in 5 out of the 6 successfully closed VSDs. Two of the patients showed mild intradevice shunt that closed spontaneously within the first 24 hours; in another 2 patients the shunt disappeared 1 month after the procedure, and in the fifth case moderate residual shunt persisted 1 month after the procedure.

All patients were discharged from the hospital within the first 48 hours after the procedure. Three out of the 7 patients were already on acetylsalicylic acid due to their underlying condition while in the remaining 3 with successful closures, treatment with acetylsalicylic acid was started before discharge. Antibiotic prophylaxis was advised for 6 months after closing the residual shunt.

Regarding the clinical course, in 5 out of the 6 patients with successful device implantation and without previous ECG alterations, no conduction abnormalities were seen after closing the VSD. However, 1 case of progression into long-term preexisting postoperative AVB was reported that required pacemaker implantation. This was the case of a patient with repaired tetralogy of Fallot (case #3) who—before the percutaneous closure of the VSD—had advanced AVB of several years of evolution without an indication for pacemaker implantation. Fourteen months after the procedure, the patient required percutaneous pacemaker implantation because data on atrioventricular conduction worsened in Holter, ergometry, and electrophysiological studies.

DISCUSSION

This is a small and heterogeneous series of occluded VSDs with the KONAR-MF device with a short follow-up too. However, we wanted to share our case since this was the first experience in our country using a device that has joined the therapeutic arsenal of occluder devices available for the percutaneous treatment of VSD. Using this device was technically easy and reproducible from the interventional cardiology standpoint. Also, the echocardiographic visualization of the device was rather good from the imaging standpoint (figure 2).

The percutaneous occlusion of VSD with the KONAR-MF device is feasible and effective with complete closure of VSD rates 1 month after implantation of up to 98%,9-12 which has been associated with the possibility of oversizing the device vs the VSD without damaging any adjacent structures given its flexibility.9-12 In our series of a single patient with residual shunt vs 5 patients without it, the rate of occlusion was 83% 1 month after implantation.

Compared to other devices, the advantages attributed to this device are its flexibility and adaptability to the patient’s anatomy, both favorable to minimize complications and increase the efficacy of occlusion. Also, other advantages are the possibility of implanting this device from the aortic side shortening procedural time.

Although, to this date, literature is scarce and only limited to early series of cases, the experience is growing, particularly in Asia.9-14 It has been used in a wide array of clinical scenarios and patients including breastfed babies13 proving effective and safe overall. However, as it occurs with all invasive procedures, it is not stranger to major complications being embolization the most common of all.10,11

The rates of success and major complications (embolization, AVB, and hemolysis) reported with this device are similar—or somehow lower—compared to those reported with other VSD closure devices.11,15 However, the rates of immediate closure are higher compared to those reported with other devices, which would—theoretically speaking—minimize the risk of complications like hemolysis or endocarditis.11,15

Our results are consistent with the series published to this date without cases of hemolysis being reported. The serious complications reported were 1 embolization, and 1 AVB at the follow-up. In our series, embolization was attributed to the fact that a small device was selected as a consequence of the mismatch reported between the VSD size measured on the TEE and on the angiography. The presence of aneurysmal tissue when trying to measure the defect properly was seen as a setback. Future cases should examine the TEE-angiography correlation when measuring the size of VSD.

The medical literature reports 2 cases of permanent AVB (another transient AVB was reported during the procedure contraindicating implantation13): 1 early AVB in the series of Tanidir et al.10 of 98 patients—a rate of AVB of 1%—plus another case deferred for a week14 that made Leong et al.14 review the rate of AVB described in the medical literature with what they referred to as «new» devices. In our sample no cases of rhythm disorders were reported after the procedure was performed in 5 out of 6 cases. However, it is relevant that in a patient with previous advanced AVB, disease progression was reported, which led to pacemaker implantation after closing the defect. Since this patient had tetralogy of Fallot, the device was implanted in a patch without prior direct compression on the cardiac conduction system. Also, this patient had a hemodynamic disorder with right ventricular overload due to acute respiratory failure, and significant stenosis of pulmonary arteries. Given this baseline situation, the worsening AVB cannot be fully attributed to the device although it cannot be discarded either. In any case, the previous presence of conduction abnormalities should be a warning of possible worsening after percutaneous closure of a VSD.

The results of our series should be interpreted in the context of its own limitations (small number of patients and short follow-up period). Although both the versatility of the device and the successful outcomes are encouraging, the presence of serious complications requires a careful approach. Therefore, larger studies with more cases and longer mid-term follow-ups are required to confirm the device safety profile.

CONCLUSIONS

The percutaneous closure of the VSD with the KONAR-MF device emerges as a proper alternative to occlusion with other devices. Also, it is a feasible alternative to surgery for some patients. Also, it stands as an effective occlusion technique in selected defects being the right anatomical assessment of the VSD one of the keys for success. The rates of complete closure and complications of this early sample should improve with more cases, experience, and longer follow-ups. As it occurs with other devices, implanting this device is associated with complications like AVB, and embolization.

FUNDING

None whatsoever.

AUTHORS’ CONTRIBUTIONS

M. Álvarez-Fuente collected the patients’ data and drafted the manuscript. J.I. Carrasco collected the patients’ data and was involved in the review process of the manuscript. B. Insa drafted the manuscript. M. Toledano was involved in the review process of manuscript. E. Peiró participated in the review process of the manuscript. J.P. Sandoval participated as an advisor in the process of drafting the manuscript, as well as the manuscript final review process. M.J. del Cerro drafted the manuscript.

CONFLICTS OF INTEREST

None reported.

REFERENCES