Scientific letter
Usability and accuracy of a cloud-based sizing software for left atrial appendage closure
Utilidad y precisión de un software basado en la nube para cierre de la orejuela izquierda
aServicio de Cardiología, Hospital Clínico Universitario de Valladolid, Valladolid, Spain bCentro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain cResearch and Development, TribusMed, Breda, The Netherlands
Home
Currently, invasive coronary angiography is still the main technique to identify obstructive coronary artery disease. However, its diagnostic yield is limited by its inability to assess the functional relevance of intermediate stenoses.1 The introduction of pressure guidewire-based physiological assessment was first enabled by the development of fractional flow reserve (FFR).2 Within the following decade, a large body of evidence supported the benefit of FFR in revascularization decision-making, leading to its endorsement by clinical practice guidelines.3-5 Still, a low penetrance of FFR was observed, due to scepticism in coronary physiology, the need for coronary instrumentation, adenosine infusion, and increased procedural time and costs.6 These challenges led to the development of several non-hyperemic indices, avoiding the need for hyperemic agents, as well as angiography-derived physiological assessment techniques (ADPAT), which avoid both the use of adenosine and coronary guidewires. Over the past few years, several ADPAT modalities have emerged with the objective of estimating FFR by combining fluid dynamic equations, 3D models of the coronary tree and certain predefined boundary flow conditions.7
Most ADPAT have pivotal validation studies that compare them to FFR showing good diagnostic accuracy. Among these methods, quantitative flow ratio (QFR) has been evaluated in the largest number of studies and, importantly, the main clinical trials powered for cardiovascular events. In the randomized FAVOR III China trial, the QFR-guided revascularization of intermediate stenoses was superior to angiography-guided revascularization,8 prompting a 1B recommendation for the use of QFR by the European clinical practice guidelines on the management of chronic coronary syndromes.9 However, when QFR was compared with FFR for clinical events in the randomized FAVOR III Europe trial it not only failed to show non-inferiority, but also had a significantly worse rate of adverse events, with a hazard ratio of 1.67 for the composite primary endpoint and 1.84 for myocardial infarction (MI).10 This has raised concerns about the reliability of QFR and its applicability as a substitute for FFR in the routine clinical practice. Figure 1 illustrates the known advantages and disadvantages of ADPAT.
Figure 1. Advantages and disadvantages of ADPAT. ADPAT, angiography- derived physiological assessment techniques; FFR, fractional flow reserve; PCI, percutaneous coronary intervention.
In a recent article published in REC: Interventional Cardiology, Ruiz-Ruiz et al. provide a meta-analysis on the combined and individual accuracy of the most frequently used ADPAT software in the setting of functional interrogation of intermediate stenoses.11 After applying eligibility criteria, a total of 27 papers were finally selected, including more than 4800 patients and more than 5400 vessel analysis. Although stable angina was the most prevalent indication, roughly a third of the patients exhibited acute coronary syndromes, mostly unstable angina. In more than half of the cases, the target vessel was the left anterior descending coronary artery. The ADPAT modalities included primarily QFR; 42.6% of vessels), angiography-derived FFR (15.5%), and vessel FFR (12.0%).
The main results from the meta-analysis suggest a good diagnostic performance of the different ADPAT tools considered vs FFR. Overall sensitivity and positive predictive value were around 85%, whereas total specificity and negative predictive value exceeded 90%, highlighting a potential value of these techniques to identify functionally non-significant stenoses and defer revascularization. The area under the curve for predicting a significant FFR was remarkable (0.947). However, evidence quality on every ADPAT software was uneven and a large proportion of pivotal studies was included in the meta-analysis, precluding the results to properly represent a real-world patients’ population. Furthermore, there were several exclusion criteria, such as > 10% prevalence of previous surgical revascularization, > 25% prevalence of atrial fibrillation, or > 30% of the patients exhibiting MI if time from the event to physiological evaluation was not specified, which means the studies included are highly selected and may not accurately reflect our routine clinical practice.
In any case, taken at face, these data of diagnostic accuracy for ADPAT seem encouraging. The pressure wire-based instantaneous wave-free ratio (iFR) demonstrated an area under the curve, as well as positive and negative predictive values very similar to those reported in this meta-analysis for ADPAT.12 This would be indicative of a similar clinical value, which is why the negative results of the FAVOR III Europe trial came as such a shock. It is well established for FFR and iFR that much of the clinical benefit of physiology-based revascularisation derives from deferral of unneeded coronary interventions.13 Similarly, the advantage of QFR over angiography in the FAVOR III China trial was associated with a lower number of lesions treated in the QFR arm.8 However, data from the FAVOR III Europe trial questioned the ability of QFR to defer as many revascularizations as FFR. In this trial, median QFR values were lower than those of FFR, leading to more than 20% additional patients undergoing revascularization in the QFR group.10 On the other hand, it could be that the inaccuracy goes both ways: a post hoc subanalysis of the trial revealed that QFR-based intervention deferral was associated with worse outcomes, especially in terms of unplanned revascularizations.14 This suggests that excess events in the QFR arm of FAVOR III Europe trial might be attributed to both false positive and false negative measurements. For reproducibility, a pre-specified sub-study of the trial compared investigator-performed QFR measurements with repeated assessments by the core laboratory. Almost 30% disagreement was documented, including both significant and non-significant QFR values.15 Of note, the study included a rigorous training and certification protocol for all the investigators involved in QFR assessment.
Clearly, the final word on these techniques has not yet been written. If we aim to predict and reduce the risk of adverse cardiovascular events, both microvascular dysfunction and plaque vulnerability are 2 factors that we should taken into consideration. The former, not only modifies the risk of cardiovascular events, but affects the accuracy of ADPAT measurements.16 The latter is a major driver of adverse coronary events, may prompt percutaneous revascularization even in physiologically non-significant lesions,17,18 and cannot be accurately estimated by any angiographic technique. In this regard, the use of intravascular imaging to assess both plaque vulnerability and physiological significance by means of dedicated algorithms seems promising.19,20 Another important unsolved issue is the performance of physiology –of any kind– in clinical scenarios other than chronic coronary syndrome. Current clinical practice guidelines from the European Society of Cardiology do not support the use of FFR in ST-segment elevation MI due to conflicting evidence, and all other physiological indexes are lacking clinical trials in this setting. Of note, MI with and without ST-segment elevation accounts for more than half of revascularization procedures in most centers with a primary percutaneous coronary intervention program in our setting. The ongoing VULNERABLE trial18 should shed light on this issue of whether physiology is sufficient to safely defer non-culprit lesions in ST-segment elevation MI, or rather a more proactive approach is needed to detect and treat vulnerable plaques. As we wait for the results of this and other trials, integrative efforts such as the meta-analysis conducted by Ruiz-Ruiz et al.11 may contribute to expand knowledge and expertise on ADPAT.
FUNDING
None declared.
CONFLICTS OF INTEREST
None declared.
REFERENCES
1. Patel MR, Peterson ED, Dai D, et al. Low Diagnostic Yield of Elective Coronary Angiography. N Engl J Med. 2010;362:886–895.
2. Pijls NHJ, Van Gelder B, Van der Voort P, et al. Fractional Flow Reserve. Circulation. 1995;92:3183–3193.
3. Tonino PAL, De Bruyne B, Pijls NHJ, et al. Fractional Flow Reserve versus Angiography for Guiding Percutaneous Coronary Intervention. N Engl J Med. 2009;360:213–224.
4. Toth G, Hamilos M, Pyxaras S, et al. Evolving concepts of angiogram:fractional flow reserve discordances in 4000 coronary stenoses. Eur Heart J. 2014;35:2831–2838.
5. De Bruyne B, Pijls NHJ, Kalesan B, et al. Fractional Flow Reserve–Guided PCI versus Medical Therapy in Stable Coronary Disease. N Engl J Med. 2012;367:991–1001.
6. Demir OM, Schrieken C, Curio J, Rahman H. Behavioural determinants impacting the adoption rate of coronary physiology. Int J Cardiol. 2021;330: 12–14.
7. Faria D, Hennessey B, Shabbir A, et al. Functional coronary angiography for the assessment of the epicardial vessels and the microcirculation. EuroIntervention. 2023;19:203–221.
8. Xu B, Tu S, Song L, et al. Angiographic quantitative flow ratio-guided coronary intervention (FAVOR III China):a multicentre, randomised, sham-controlled trial. Lancet. 2021;398:2149–2159.
9. Vrints C, Andreotti F, Koskinas KC, et al. 2024 ESC Guidelines for the management of chronic coronary syndromes. Eur Heart J. 2024;45:3 415–3537.
10. Andersen BK, Sejr-Hansen M, Maillard L, et al. Quantitative flow ratio versus fractional flow reserve for coronary revascularisation guidance (FAVOR III Europe):a multicentre, randomised, non-inferiority trial. Lancet. 2024;404:1835–1846.
11. Ruiz-Ruiz J, Cortés-Villar C, Fernández-Cordón C, et al. Angiography- derived index versus fractional flow reserve for intermediate coronary lesions:a meta-analysis review. REC Interv Cardiol. 2025. https://doi.org/10.24875/RECICE.M25000523.
12. Sen S, Escaned J, Malik IS, et al. Development and Validation of a New Adenosine-Independent Index of Stenosis Severity From Coronary Wave–Intensity Analysis. J Am Coll Cardiol. 2012;59:1392–1402.
13. Escaned J, Ryan N, Mejía-Rentería H, et al. Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes. JACC Cardiovasc Interv. 2018;11: 1437–1449.
14. Andersen BK, Holm NR, Mogensen LJH, et al.; behalf of the FAVOR III Europe Study Team. Coronary revascularisation deferral based on quantitative flow ratio or fractional flow reserve:a post hoc analysis of the FAVOR III Europe trial. EuroIntervention. 2025;21:161–170.
15. Kristensen SK, Holm MB, Maillard L, et al. Re-analysis and quality assessment of QFR in the FAVOR III Europe trial. The REPEAT-QFR study. In:EuroPCR 2025;2025 May 20-23;Paris, France. Available at:https://www.pcronline.com/Cases-resources-images/Resources/Course-videos-slides/ 2025/EuroPCR/How-coronary-physiology-may-help-in-guiding-treatment-of- NSTEMI. Accessed 9 Sep 2025.
16. Mejia?Renteria H, Lee JM, Choi K, et al. Coronary microcirculation assessment using functional angiography:Development of a wire?free method applicable to conventional coronary angiograms. Catheter Cardiovasc Interv. 2021;98:1027–1037.
17. Park S-J, Ahn J-M, Kang D-Y, et al. Preventive percutaneous coronary intervention versus optimal medical therapy alone for the treatment of vulnerable atherosclerotic coronary plaques (PREVENT):a multicentre, open-label, randomised controlled trial. Lancet. 2024;403:1753–1765.
18. Gómez-Lara J, López-Palop R, Rúmiz E, et al. Treatment of functionally nonsignificant vulnerable plaques in multivessel STEMI:design of the VULNERABLE trial. REC Interv Cardiol. 2024. https://doi.org/10.24875/RECICE.M24000468.
19. Yu W, Tanigaki T, Ding D, Wu P, Du H, Ling L, Huang B, Li G, Yang W, Zhang S, et al. Accuracy of Intravascular Ultrasound-Based Fractional Flow Reserve in Identifying Hemodynamic Significance of Coronary Stenosis. Circ Cardiovasc Interv. 2021;14:009840.
20. Jeremias A, Maehara A, Matsumura M, et al. Optical Coherence Tomography–Based Functional Stenosis Assessment:FUSION—A Prospective Multicenter Trial. Circ Cardiovasc Interv. 2024;17:013702.
We have witnessed a remarkable evolution in the field of percutaneous coronary intervention (PCI) over the past half a century, transitioning from the first cases of balloon angioplasty to bare metal stents and, most notably, to the widespread use of drug-eluting stents (DES). The advent of DES substantially reduced restenosis rates by providing a mechanical scaffold combined with sustained release of an antiproliferative drug, eg, taxanes and then rapamycin derivatives. Considering their permanent and static nature, such metallic implants are not without limitations, including the potential for delayed healing, chronic inflammation, inhibition of positive vessel remodeling, and the need for prolonged antithrombotic therapy.1,2 Following this, the concept of bioresorbable vascular scaffolds emerged, promising a temporary scaffold that would “leave nothing behind”. Nonetheless, their initial promise was hampered by late scaffold thrombosis and a high rate of target lesion failure.3 At the same time, drug-coated balloons (DCB) emerged as a “metal-free” alternative delivering an antiproliferative drug to the vessel wall without leaving a permanent implant, thus preserving vessel anatomy, function, and allowing for adaptive remodeling. Currently, DCB are established in percutaneous coronary intervention (PCI) for in-stent restenosis (ISR) and, subsequently, for small-vessel native disease. Their role in larger native coronary arteries, however, remains debated, given the limited evidence from small randomized controlled trials (RCTs) with relatively short follow-up.4
In this context, in a recent paper published in REC: Interventional Cardiology, Sorolla Romero et al. report a timely and rigorous meta-analysis of RCT comparing DCB with DES in patients with native large coronary artery disease (PROSPERO CRD42024602012).5 A total of 2961 patients (n = 1476 for DCB and n = 1485 for DES) from 7 RCT published from 2016 through 2024 were included, and, compared with DES, DCB were associated with a similar risk of the primary endpoint of target lesion revascularization, and all-cause and cardiovascular mortality, myocardial infarction, and major adverse cardiovascular events, but a > 2-fold risk of target vessel revascularization. For angiographic outcomes, although DCB caused less late lumen loss, they were associated with a smaller minimal lumen diameter at follow-up. In light of these results, we hereby hope to provide current and future perspectives on the role of DCB for treatment of native large coronary artery disease.
LESION CHARACTERISTICS
The type of lesions included in the analyzed RCT is a key determinant of the external validity of the study findings, and we outline key considerations below.
- – Across the 7 RCT, patients with high clinical and anatomical complexity were consistently excluded (table 1).6-12 Notably, patients with extensive coronary artery disease (eg, long or multiple lesions, 3-vessel disease, or those requiring multiple devices), severe calcification, left main involvement, or chronic total occlusions were not evaluated. Additional characteristics that appeared among exclusion criteria, and could instead arguably represent favorable scenarios for DCB angioplasty, are requirement for hemodialysis, bifurcations lesions requiring treatment of both branches, and severe coronary artery tortuosity. This selective enrollment underscores the contrast with recent observational studies of DCB use in native large coronary artery disease, which have examined more complex scenarios in which DES may be less effective, technically challenging to deliver, or best avoided to limit long stent segments or multiple overlapping implants (figure 1).13-15
- – The degree of inter-study variability is also of note, particularly given the disproportionate contribution of individual RCT. As appropriately highlighted by the authors, REC-CAGEFREE I7 alone accounts for approximately 75% of the total patient population, and leave-one-out analyses yield different results. Moreover, enrollment periods span 8 years (2014–2022), introducing potential variability in procedural techniques, device technology, and adjunctive pharmacotherapy. The observed prediction intervals and measures of heterogeneity further support this consideration.
- – We acknowledge the clinical variability in defining “large” coronary artery disease. This meta-analysis applied a ≥ 2.5 mm-cutoff to define large vessels, which is at the lower end of what many would consider large. In several of the included studies, patients were eligible for enrollment regardless of treated vessel diameter, with some RCT allowing lesions within reference vessel diameters as small as 2.0 mm (table 1). Subgroup analyses within individual studies provide more specific insights into patients treated with larger devices. Given the significant interaction P value in the vessel size subgroup analysis of the largest included RCT,7 it is reasonable to question whether the overall results would have been superimposable had the analysis been limited to larger vessels. These observations should be interpreted in the context of the earlier discussion on the type of lesions included. Finally, this aspect may have sex-specific relevance: although women generally have smaller coronary vessels, a vessel of a given diameter may be more proximal and supply a larger myocardial territory in women than in men, potentially amplifying its clinical significance.16
Table 1. Clinical, angiographic and procedural characteristics excluding patients from each study included in the meta-analysis
| Characteristics | Nishiyama et al.6 (CCS) N = 60 | REC-CAGEFREE I7 (45%, CCS; 55%, ACS) N = 2271 | Yu et al.8 (11%, CCS; 89%, ACS) N = 170 | REVELATION9 (STEMI) N = 120 | Wang et al.10 (STEMI) N = 184 | Gobi´c et al.11 (STEMI) N = 75 | Hao et al.12 (STEMI) N = 80 |
|---|---|---|---|---|---|---|---|
| Age, years | > 70 | > 80 | |||||
| Hemodialysis | X | ||||||
| Previous MI | X | ||||||
| Previous PCI/CABG | Within 6 months | Within 6 months | |||||
| Vessel size, mm | < 2.25 or > 4.0 | < 2.0 or > 4.0 | < 2.5 or > 4.0 | ||||
| Lesion length, mm | ≥ 25 | > 30 | |||||
| No. of DES or DCB/total DES or DCB length, mm | ≥ 3/> 60 | ||||||
| Extensive CAD | ≥ 3 lesions/vessels | X | |||||
| Severe calcification or atherectomy | X | X | X | X | |||
| Left main coronary artery | X | X | |||||
| CTO | X | X | |||||
| Bifurcation requiring treatment in both branches | X | ||||||
| Grafts | X | ||||||
| Severe coronary artery tortuosity | X | ||||||
|
ACS, acute coronary syndrome; CABG, coronary artery bypass grafting; CAD, coronary artery disease; CCS, chronic coronary syndrome; CTO, chronic total coronary occlusion; DCB, drug-coated balloon; DES, drug-eluting stent; MI, myocardial infarction; PCI, percutaneous coronary intervention; STEMI, ST-segment elevation myocardial infarction. |
|||||||
Figure 1. Patient and lesion factors to be taken into consideration when evaluating native large coronary artery disease for percutaneous coronary intervention. Presence of any one of the factors highlighted beneath DCB should lead the operator to contemplate an approach to limit the number of permanent coronary artery implants. ACS, acute coronary syndrome; CKD, chronic kidney disease; CTO, chronic total coronary occlusion; DCB, drug-coated balloon; DES, drug-eluting stent; DM, diabetes mellitus; HBR, high bleeding risk.
LESION PREPARATION
Lesion preparation is a point of significant heterogeneity among the RCT included in the meta-analysis. For example, the REVELATION trial,9 conducted on patients with ST-segment elevation myocardial infarction, permitted proceeding with DCB angioplasty with a 50% residual percent diameter stenosis after predilation, and thrombectomy if visible thrombus was present, which contrasts with the more commonly embraced ≤ 30% threshold.5 Further complicating the procedural comparison is the timing of patient randomization, as 2 studies randomized patients before assessing the outcome of lesion preparation.10,11 Moreover, the specific methods of lesion preparation varied, with 1 study supporting the use of semicompliant balloon angioplasty before DCB inflation.12 The success of DCB angioplasty depends on a dedicated procedural strategy that hinges on meticulous lesion preparation and careful postoperative assessment, a nuance often lost when comparing outcomes across various methodologies.15,17,18
DCB CHARACTERISTICS
The field is characterized by a diversity of DCB platforms, antiproliferative agents and coatings. While the included RCT largely focus on paclitaxel-coated balloons, a growing body of evidence highlights differences in vascular response, downstream effects, and pharmacokinetics across different DCB, indicating that the choice of drug and coating technology could arguably influence clinical outcomes. Sirolimus-coated balloons have recently shown promising results in various clinical settings. Moving forward, future efforts should continue to differentiate between different technologies, as their clinical performance may not be uniform.19,20 Of note, the balloon coating and mechanism of drug release are also key aspects that should be taken into consideration. The DCB technologies assessed in this meta-analysis all used paclitaxel coating but different in platform; only 3 trials evaluated the same device (DCB; SeQuent Please, B. Braun, Germany) whereas the remaining studies used distinct systems, including an ultrasound-controlled paclitaxel delivery platform.10 Finally, inflation time is important for drug delievery and this was not uniform in the studies included in the meta-analysis, with recommended DCB inflation times as low as 30 seconds.6 Recommendations among studies currently enrolling (MAGICAL SV [NCT06271590] and Prevail Global [NCT06535854]) are also slightly different, and whether this might have clinical implications is still to be elucidated.
ANGIOGRAPHIC AND CLINICAL OUTCOMES
DES implantation typically provides a larger acute gain in lumen diameter than balloon angioplasty, a concept highlighted also within the REVELATION trial,9 where the residual percent diameter stenosis to define a successful procedure was different after DCB angioplasty (< 30%) and DES implantation (< 20%). While the meta-analysis reports the endpoint late lumen loss, we recognize that this metric may not fully capture the relative efficacy of these 2 technologies. The use of endpoints, such as net lumen gain, providing a more comprehensive and meaningful comparison between these 2 fundamentally different strategies by focusing on the overall therapeutic effect on the vessel lumen, rather than just the restenotic response following the intervention, should be implemented in upcoming studies. In addition, we acknowledge the limitation in comparing the incidence rate of composite endpoints such as major adverse cardiovascular events when these include different single components across the studies. Finally, we highlight the importance for future studies to concentrate on the reporting of any target vessel thrombosis, a key safety endpoint which remained underreported in the meta-analysis. Still, a significant concern in clinical practice and a key factor impacting the wider implementation of a DCB-based strategy (COPERNICAN [NCT06353594]).
CONCLUSIONS
The meta-analysis by Sorolla Romero et al. provides a timely summary of the current evidence on the use of DCB in large native coronary arteries, and its findings provide hypothesis-generating evidence that challenges the long-standing paradigm of DES as the default choice for any lesion. This work underscores that the evolution of PCI is ongoing and invites reconsideration of therapeutic algorithms toward a more personalized approach, in which the choice between DCB and DES is guided by patient- and lesion-specific factors (figure 1). Moving forward, the focus must shift towards refining patient selection, optimizing procedural techniques, and conducting further RCT with long-term follow-up to clarify the role of DCB in this new therapeutic paradigm.
FUNDING
None declared.
CONFLICTS OF INTEREST
None declared.
REFERENCES
1. Colombo A, Leone PP. Redefining the way to perform percutaneous coronary intervention:a view in search of evidence.
2. Colombo A, Leone PP, Ploumen EH, von Birgelen C. Drug-coated balloons as a first choice for patients with de novo lesions:pros and cons.
3. Regazzoli D, Latib A, Ezhumalai B, et al. Long-term follow-up of BVS from a prospective multicenter registry:Impact of a dedicated implantation technique on clinical outcomes.
4. Camaj A, Leone PP, Colombo A, et al. Drug-Coated Balloons for the Treatment of Coronary Artery Disease:A Review.
5. Sorolla Romero JA, Novelli L, LLau Garcia J, et al. Drug-coated balloons vs drug-eluting stents for the treatment of large native coronary artery disease. Meta-analysis of randomized controlled trials.
6. Nishiyama N, Komatsu T, Kuroyanagi T, et al. Clinical value of drug-coated balloon angioplasty for de novo lesions in patients with coronary artery disease.
7. Gao C, He X, Ouyang F, et al. Drug-coated balloon angioplasty with rescue stenting versus intended stenting for the treatment of patients with de novo coronary artery lesions (REC-CAGEFREE I):an open-label, randomised, non-inferiority trial.
8. Yu X, Wang X, Ji F, et al. A Non-inferiority, Randomized Clinical Trial Comparing Paclitaxel-Coated Balloon Versus New-Generation Drug-Eluting Stents on Angiographic Outcomes for Coronary De Novo Lesions.
9. Vos NS, Fagel ND, Amoroso G, et al. Paclitaxel-Coated Balloon Angioplasty Versus Drug-Eluting Stent in Acute Myocardial Infarction:The REVELATION Randomized Trial.
10. Wang Z, Yin Y, Li J, et al. New Ultrasound-Controlled Paclitaxel Releasing Balloon vs. Asymmetric Drug-Eluting Stent in Primary ST-Segment Elevation Myocardial Infarction-A Prospective Randomized Trial.
11. Gobi´c i D, Tomuli´c V, Luli´c D, et al. Drug-Coated Balloon Versus Drug-Eluting Stent in Primary Percutaneous Coronary Intervention:A Feasibility Study.
12. Hao X, Huang D, Wang Z, Zhang J, Liu H, Lu Y. Study on the safety and effectiveness of drug-coated balloons in patients with acute myocardial infarction.
13. Leone PP, Oliva A, Regazzoli D, et al. Immediate and follow-up outcomes of drug-coated balloon angioplasty in de novo long lesions on large coronary arteries.
14. Tartaglia F, Gitto M, Leone PP, et al. Validation of complex PCI criteria in drug-coated balloon angioplasty.
15. Leone PP, Gitto M, Gao C, Sanz Sánchez J, Latib A, Colombo A. Rethinking coronary artery metal implants.
16. Leone PP, Testa L, Greco A, et al. Two-Year Clinical Outcomes in Female and Male Patients After Sirolimus-Coated Balloon Angioplasty for Coronary Artery Disease.
17. Gitto M, Leone PP, Gioia F, et al. Coronary Artery Dissection in Drug-Coated Balloon Angioplasty:Incidence, Predictors, and Clinical Outcomes.
18. Leone PP, Mangieri A, Regazzoli D, et al. Drug-Coated Balloon Angioplasty Guided by Postpercutaneous Coronary Intervention Pressure Gradient:The REDUCE-STENT Retrospective Registry.
19. Leone PP, Heang TM, Yan LC, et al. Two-year outcomes of sirolimus-coated balloon angiopla,sty for coronary artery disease:the EASTBOURNE Registry.
20. Leone PP, Calamita G, Gitto M, et al. Sirolimus- Versus Paclitaxel-Coated Balloons for Treatment of Coronary Artery Disease.
To the Editor,
Transcatheter aortic valve implantation (TAVI) has revolutionized the management of severe aortic stenosis (AS).1 Despite increasing TAVI experience and procedural improvement, outcomes remain hard to foresee.1 Several clinical and anatomical risk factors have been well established as independent predictors of adverse events.2 Nonetheless, the macro-level interactions between them are complex and challenging to quantify with traditional models, particularly given the dynamic clinical trajectory of AS.
Although standardized risk scores, such as the Society of Thoracic Surgeons (STS) score and the EuroSCORE II offer estimates of procedural risk3 they miss the broader clinical profile and interactions. Advanced statistical techniques, such as multivariate cluster analysis, can identify subgroups, potentially uncovering patterns overlooked by conventional risk stratification. This study aimed to stratify TAVI patients using a 2-step cluster analysis based on clinical and risk factor variables and evaluate the association between these clusters and procedural timing and clinical outcomes.
We conducted a retrospective, single-center study with 300 patients undergoing TAVI from 2020 through 2023, without immediate cardiac surgery back-up. Data were retrospectively analyzed. Procedural and outcome definitions followed the Valve Academic Research Consortium-3 criteria.4 A 2-step cluster analysis was performed, incorporating variables such as age, sex, New York Heart Association (NYHA) functional class, significant mitral regurgitation, pulmonary hypertension, and relevant comorbidities, including chronic kidney disease and atrial fibrillation.
Clusters were compared regarding baseline characteristics, procedural variables, and outcomes. The primary composite endpoint was 30-day mortality, stroke, and 1-year hospital readmission. Secondary endpoints included 1-year mortality, stroke, hospital readmission, permanent pacemaker implantation, and vascular complications. Statistical analyses were performed using IBM SPSS Statistics, Version 30.0 (IBM Corp., Armonk, NY, USA).
Two clusters were identified: Cluster 1 (n = 182) and Cluster 2 (n = 32) (silhouette coefficient, 0.69). The remaining patients had incomplete data for clustering variables. Baseline demographic and comorbidity profiles were similar between clusters. Mean age (82 ± 5 vs 83 ± 5 years; P = .6), female sex (54% vs 50%; P = .7), and comorbidities did not differ significantly (table 1). Additionally, echocardiographic and computed tomography parameters were similar between the 2 clusters (table 1).
Table 1. Baseline characteristics, procedural data, and clinical outcomes according to cluster analysis in patients undergoing TAVI
| Variable | Total (n = 300) | Cluster 1 (n = 182) | Cluster 2 (n = 32) | P-value |
|---|---|---|---|---|
| Baseline | ||||
| Age | ||||
| Mean, SD | 82 ± 5 | 82 ± 6 | 83 ± 5 | .6 |
| Median, IQR | 82 [78-86] | 82 [78-86] | 84 [79-87] | |
| Female, (%) | 54% | 54% | 50% | .7 |
| Katz score > 4 (%) | 96% | 97% | 94% | .6 |
| STS score | ||||
| Mean, SD | 5.2 ± 4.5 | 4.9 ± 4.2 | 5.8 ± 4.3 | .3 |
| Median, IQR | 3.8 [2.8-6.9] | 3.7 [2.7-6.6] | 4.0 [2.8-7.8] | |
| STS score high risk (> 8) | 17% | 13% | 22% | .2 |
| EuroSCORE | 2.32-2.4 | 2.2-2 | 2.6-2 | .5 |
| Hospital admission due to AS | 22% | 28% | 3% | .03 |
| NYHA > 2 | 51% | 52% | 25% | .005 |
| Comorbidities | ||||
| HTN | 86% | 85% | 88% | .7 |
| DM | 35% | 36% | 41% | .6 |
| CAD | 21% | 16% | 25% | .2 |
| COPD/OSA | 11% | 10% | 16% | .3 |
| GFR < 30 mL/kg/m2 | 11% | 11% | 16% | .5 |
| Atrial fibrillation | 22% | 24% | 19% | .5 |
| MI | 9% | 9% | 13% | .5 |
| PCI | 14% | 12% | 22% | .1 |
| Stroke | 8% | 8% | 18% | .07 |
| ECG | ||||
| 1st AV block | 12% | 11% | 13% | .8 |
| LBBB | 9% | 8% | 7% | .8 |
| RBBB | 7% | 6% | 16% | .05 |
| TTE | ||||
| Mean gradient (mmHg) | 48 ± 14 | 49 ± 13 | 46 ± 15 | .2 |
| AVA (cm2) | 0.7 ± 0.2 | 0.7 ± 0.2 | 0.8 ± 0.2 | .08 |
| LVEF (%) | 56 ± 11 | 55 ± 10 | 57 ± 10 | .7 |
| LVEF < 40% | 13% | 10% | 10% | .9 |
| SPAP > 40mmHg | 54% | 64% | 43% | .03 |
| Significant MR | 30% | 30% | 12% | .05 |
| CT | ||||
| Aortic calcium score | 721 ± 88 | .3 | ||
| Min femoral diameter (mm) | 7.3-1.8 | 7.0-1.9 | 7.3-1.6 | .3 |
| Laboratory findings | ||||
| Hemoglobin | 12.2 ± 1.9 | 12.3 ± 1.8 | 12.1 ± 2.2 | .8 |
| Serum creatinine | 1.2, 0.6 | 1.0, 0.6 | 1.0, 0.8 | .8 |
| NT-proBNP | 526 ± 284 | 510 ± 269 | 657 ± 291 | .09 |
| TAVI waiting time (days) | 60-101 | 48-98 | 93-92 | .03 |
| Outcomes | ||||
| Death, stroke and hospital readmission | 25% | 12% | 100% | < .001 |
| 30-day mortality rate | 3.7% | 1% | 6% | .05 |
| 1-year mortality rate | 12% | 7% | 29% | < .001 |
| Stroke | 2.8% | 0.5% | 16% | < .001 |
| Hospital admission | 17% | 13% | 88% | < .01 |
| Pacemaker implantation | 20% | 21% | 23% | .9 |
| Vascular complication | 7.8% | 5.5% | 9.4% | .4 |
|
AS, aortic stenosis; AV, atrioventricular; AVA, aortic valve area; CAD, coronary artery disease; CT, computed tomography; COPD, chronic obstructive pulmonary disease; DM, diabetes mellitus; ECG, electrocardiogram; GFR, glomerular filtration rate; HTN, hypertension; IQR, interquartile range; LBBB, left bundle branch block; LVEF, left ventricular ejection fraction; MI, myocardial infarction; MR, mitral regurgitation; NT-proBNP, N-terminal pro-Btype natriuretic peptide; NYHA, New York Heart Association; OSA, obstructive sleep apnea; PCI, percutaneous coronary intervention; RBBB, right bundle branch block; SD, standard deviation; SPAP, systolic pulmonary artery pressure; STS, Society of Thoracic Surgeons; TAVI, transcatheter aortic valve implantation; TTE, transthoracic echocardiogram. Data are expressed as no. (%), mean ± standard deviation or median [interquartile range]. |
||||
Differences emerged in clinical presentation and procedural timing. Cluster 1 had a higher proportion of NYHA III/IV patients (52% vs 25%; P = .005), previous hospitalization for AS (28% vs 3%; P = .03), significant mitral regurgitation (30% vs 12%; P = .05), and pulmonary hypertension (64% vs 43%; P = .03) at baseline initial assessment. Notably, these patients had a significantly shorter median TAVI waiting time (48 [24-72] vs 93 [47-139] days; P = .03), suggesting a prioritization based on symptomatic burden and perceived procedural urgency.
Despite patients from Cluster 1 being more symptomatic, their outcomes were better vs those from Cluster 2. The primary composite endpoint of death, stroke, and hospital readmission occurred in 12% of Cluster 1 patients vs 100% of Cluster 2 patients (risk ratio [RR], 8.3; 95% confidence interval [95%CI], 5.2-13.3; P < .001). The 30-day all-cause mortality rate was 1% in Cluster 1 vs 6% in Cluster 2 (RR ,5.7; 95%CI, 0.8-38.9; P = .05). The 1-year mortality rate remained significantly lower in Cluster 1 at 7% vs 29% in Cluster 2 (RR, 4.1; 95%CI, 1.9-8.6; P < .001). Similarly, stroke occurred in only 0.5% of patients from Cluster 1 while 16% of the patients from Cluster 2 experienced this complication (RR, 33.3; 95%CI, 4.5-247.7; P < .001). The 1-year rate of hospital readmissions was also less common in Cluster 1, occurring in 13% of patients vs 88% in Cluster 2 (RR, 6.77; 95%CI, 3.7-12.5; P < .01). Rates of vascular complications and permanent pacemaker implantation were similar between the clusters (5.5% vs 9.4%, RR, 1.7; 95%CI, 0.5-5.7; P = .4 and 21% vs 23%, RR, 1.10; 95%CI, 0.6-2.2; P = .9, respectively).
This study demonstrates that multivariate clustering can identify distinct clinical profiles within a TAVI cohort, revealing paradoxical but clinically meaningful outcome patterns. Patients with advanced symptoms (NYHA III/IV) and prior AS-related hospitalizations, typically considered higher risk, achieved better survival and lower complication rates vs less symptomatic patients.
Procedural timing and patient surveillance intensity might contribute to the different outcomes reported. More symptomatic patients tend to undergo closer clinical follow-up and prioritized TAVI scheduling, as reflected by the significantly shorter waiting times observed in Cluster 1. Conversely, patients with less severe symptoms are often deprioritized, experiencing procedural delays during which subclinical deterioration or decline in functional status can be significant. AS is a progressive condition, with substantial mortality on the waiting list. Moreover, a history of unplanned hospital admission for AS should be considered a significant warning sign to anticipate intervention, given its association with increased risk of subsequent events. Former studies have shown that delayed intervention is associated with higher rates of adverse outcomes,5 thus supporting the notion that waiting time is a critical modifiable risk factor. Moreover, current risk prediction models inadequately account for dynamic clinical evolution and complex factor interactions. STS and EuroSCORE II values were comparable between clusters, yet outcomes differed substantially. The higher outcome rate from Cluster 2 raises concerns about unrecognized vulnerability and cumulative procedural risk aggravated by disease progression during the waiting period. These findings suggest that, beyond baseline comorbidities, procedural timing and dynamic clinical follow-up should be part of risk stratification and procedural prioritization strategies in TAVI programs.
This study has several limitations. Its retrospective single-center design may limit external validity. Small sample size, especially in Cluster 2, limits power. Unmeasured factors, such as frailty may have influenced outcomes. The 2-step cluster model, while robust, is sensitive to the included variables and missing data, potentially affecting cluster assignment and interpretation. Additionally, our conclusions may not be applicable to centers with short waiting lists.
This clustering method allows a macroscopic view and the identification of potential interactions between multiple clinical variables by organizing patients into groups. However, further studies with larger sample sizes are needed to validate this risk assessment approach. These findings highlight the importance of minimizing waiting times and ensuring close follow-up in managing AS. Multidimensional clinical profiling and dynamic procedural scheduling should be considered when optimizing TAVI care pathways to improve patient outcomes.
DATA AVAILABILITY
The data that support the findings of this study are available from the corresponding author upon reasonable request
FUNDING
None declared.
ETHICAL CONSIDERATIONS
This study was conducted in full compliance with the Declaration of Helsinki and the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines on clinical research. As a retrospective analysis of anonymized data, formal ethical approval and informed consent were waived. This study was conducted in full compliance with the SAGER (Sex and Gender Equity in Research) guidelines. Sex and gender considerations were addressed appropriately, and any potential sex- or gender-related differences were assessed and reported where relevant.
STATEMENT ON THE USE OF ARTIFICIAL INTELLIGENCE
No artificial intelligence tools were used in the preparation of this manuscript.
AUTHORS’ CONTRIBUTIONS
A. Rocha de Almeida: conceptualization, methodology, data curation, formal analysis, investigation, writing – original draft, writing – review and editing. R. Viana: writing – original draft, writing – review and editing. R. Fernandes: writing – review and editing. Â. Bento: writing – review and editing. L. Patrício: conceptualization, supervision, writing – review and editing, validation.
CONFLICTS OF INTEREST
None declared.
REFERENCES
1. Vahanian A, Beyersdorf F, Praz F, et al. 2021 ESC/EACTS Guidelines for the management of valvular heart disease. Eur Heart J. 2022;43:561-632.
2. Carroll JD, Mack MJ, Vemulapalli S, et al. STS-ACC TVT Registry of Transcatheter Aortic Valve Replacement. J Am Coll Cardiol. 2020;76:2492-2516.
3. Wendler O, Schymik G, Treede H, et al. SOURCE 3 Registry. Circulation. 2017;135:1123-1132.
4. Généreux P, Piazza N, Alu MC, et al. Valve Academic Research Consortium 3:updated endpoint definitions for aortic valve clinical research. Eur Heart J. 2021;42:1825-1857.
5. Bhattacharyya S, Lloyd G. Mortality whilst waiting for intervention in symptomatic severe aortic stenosis. Eur Heart J Qual Care Clin Outcomes. 2020;6:89-90.
To the Editor,
The complex and highly variable 3D anatomy of the left atrial appendage (LAA) makes it challenging for planning and device sizing for left atrial appendage closure (LAAC).1 Echocardiography and multi-slice computed tomography (CT) are widely used imaging modalities for this purpose. 3Mensio Structural Heart (Pie Medical Imaging BV, The Netherlands) is the most widely used software for CT evaluation of LAA providing automatic segmentation of the heart. TribusConnect (TribusMed Beheer BV, The Netherlands) is a novel cloud-based Digital Imaging and Communications in Medicine (DICOM) viewer that can also be used to securely access, review, interpret, manipulate, measure and visualize images with automatic cardiac segmentation for LAA evaluation. Furthermore, TribusConnect allows for manual correction or adjustment of the automatically generated measurements or segmentation which could be crucial for centers with varying image quality, or challenging anatomies. This study aimed to investigate the feasibility, accuracy and reproducibility of evaluating the LAA in TribusConnect compared with the 3Mensio for preprocedural planning of LAAC.
Seventeen patients who underwent LAAC at Hospital Clínico Universitario de Valladolid (Valladolid, Spain) were included in our study. A total of 52.9% (9 patients) of these patients underwent LAAC by Amplatzer Amulet (Abbott, United States) while 17.6% (3 patients) and 29.4% (5 patients) received the Watchman (Boston Scientific, United States) and Omega (Vascular Innovations, Thailand) left atrial appendage occlude devices, respectively. The device size used varied from 18 mm to 35 mm. Only 1 of the 17 patients had mild peridevice leak (< 3 mm) due to device malapposition while 0 patients had device embolization or need for changing the device size or device type during the procedure. All patients underwent preoperative contrast-enhanced, electrocardiogram-gated high-pitch spiral acquisition mode CT. Images were obtained at 30%-60% of the R-R interval with a delayed scan after contrast injection in full compliance with LAA-specific expert recommendations on CT acquisition.2 All datasets were saved as DICOM files and processed with dedicated software (3mensio Structural Heart) and novel TribusConnect. In the presence of inadequate delineation of the endocardial border due to incomplete contrast opacification of the LAA, the images were considered insufficient and excluded from the study. All datasets were evaluated, and measurements were performed by 2 independent cardiologists. Conventional measurements of LAA sizes (ostium, landing zone, depth, and working depth) were compared. The landing zone (LZ) was defined at a location 10 mm from the ostium into the LAA after adjusting the angle. The working depth was measured as a perpendicular line drawn from ostium to the LAA roof.
The intraclass correlation coefficients (ICC) between TribusConnect and 3Mensio for minimum, maximum, and mean diameters were, respectively, 0.912 (95%CI, 0.780-0.967), 0.826 (95%CI, 0.592-0.933), and 0.944 (95%CI, 0.852-0.979) at the ostium, and 0.667 (95%CI, 0.058-0.887), 0.806 (95%CI, 0.548-0.925), and 0.835 (95%CI, 0.371-0.948) at the LZ. This showed a good intraclass correlation. The Bland Altman plot for the measurements of ostium and LZ using the 2 software applications is shown in figure 1. ICC were 0.666 (95%CI, 0.286-0.865) for LAA depth and 0.753 (95%CI, 0.451-0.902) for working depth.
Figure 1. Bland Altman Plot showing the difference in measurement of minimum, maximum and mean diameter at ostium (A,B,C) and landing zone (D,E,F) between TribusConnect and 3Mensio. SD, standard deviation.
The ICC for the interobserver analysis for TribusConnect at the ostium (minimum, maximum, mean diameters) was 0.941 (0.846-0.978), 0.978 (0.941-0.992) and 0.973 (0.928-0.990) vs 0.901 (0.753-0.963), 0.815 (0.526-0.931) and 0.861 (0.662-0.947) for 3Mensio. Similarly, at the LZ, the ICC for TribusConnect (minimum, maximum, mean diameters) was 0.887 (0.719-0.957), 0.873 (0.689-0.952) and 0.941 (0.849-0.978) vs 0.736 (0.404-0.896), 0.718 (0.390-0.887) and 0.831 (0.602-0.935) for 3Mensio reflecting a better reproducibility of results across different operators with TribusConnect.
ICC for depth and working depth measurements was high for both systems. For TribusConnect, ICCs were 0.813 (95%CI, 0.445-0.935) for depth and 0.828 (95%CI, 0.467-0.941) for working depth. For 3Mensio, ICCs were 0.761 (95%CI, 0.348-0.914) for depth and 0.845 (95%CI, 0.629-0.941) for working depth.
TribusConnect was deemed by the operators to have better accessibility (video 1 of the supplementary data). Since it is a cloud-based software with no need for any licensing or software installation into a device, CT images can be retrieved from any device and location across the globe. Secondly, TribusConnect has a workflow agnostic approach, bringing the user directly into the LAA without the need for restrictive steps in a workflow. Thirdly, TribusConnect ensures better data safety as no patient data is downloaded and the CT is anonymised by the software. Fourthly, all results are automatically saved, and the analysed results can be shared wherein multiple users can view, edit or improve the analysis. This was a retrospective study with a small number of patients with potential influence of unknown confounders. Further progressive studies might be needed to assess the impact of usability of this novel software on LAA device sizing and eventually clinical outcomes.
The study demonstrates a strong ICC between TribusConnect and 3Mensio in the CT assessment of the LAA for LAAC. TribusConnect exhibited lower interobserver variability and provided the added benefit of remote access to patient data.
FUNDING
None declared.
ETHICAL CONSIDERATIONS
This study did not involve patient participants or animals, which is why ethical clearance was deemed unnecessary. Although this study included male and female patients alike, sex disaggregated analyses were not performed due to lack of expected sex related differences.
STATEMENT ON THE USE OF ARTIFICIAL INTELLIGENCE
No artificial intelligence tools were used in the writing of this study.
AUTHORS’ CONTRIBUTIONS
A. Jain and I.J. Amat-Santos conducted the study and wrote the draft. The remaining authors helped to collect the data. All authors approved the final version.
CONFLICTS OF INTEREST
L. Verstraaeten and J. Vogelaar are shareholders and employees of TribusMed. The remaining authors declared no conflicts of interest whatsoever.
SUPPLEMENTARY DATA
Vídeo 1. Jain A. DOI: 10.24875/RECICE.M25000536
REFERENCES
1. Heidari H, Kanschik D, Erkens R, et al. Left atrial appendage sizing for percutaneous closure in virtual reality-a feasibility study. Front Cardiovasc Med. 2023;10:1188571.
2. Korsholm K, Berti S, Iriart X, et al. Expert Recommendations on Cardiac Computed Tomography for Planning Transcatheter Left Atrial Appendage Occlusion. JACC Cardiovasc Interv. 2020;13:277-292.
Page 1 of 4
Special articles
Original articles
Editorials
Original articles
Editorials
Post-TAVI management of frail patients: outcomes beyond implantation
Unidad de Hemodinámica y Cardiología Intervencionista, Servicio de Cardiología, Hospital General Universitario de Elche, Elche, Alicante, Spain
Original articles
Debate
Debate: Does the distal radial approach offer added value over the conventional radial approach?
Yes, it does
Servicio de Cardiología, Hospital Universitario Sant Joan d’Alacant, Alicante, Spain
No, it does not
Unidad de Cardiología Intervencionista, Servicio de Cardiología, Hospital Universitario Galdakao, Galdakao, Vizcaya, España


