Debate: MitraClip. The heart failure expert perspective

QUESTION: Do you think there is enough evidence to indicate the use of intravascular imaging during percutaneous coronary interventions?

ANSWER: Currently, there is enough evidence on the benefits provided by intracoronary imaging modalities during percutaneous coronary interventions. Actually, the clinical practice guidelines recommend their use. For the most part, evidence has been collected on the use of these imaging modalities to optimize angioplasty. In this sense, the 2018 guidelines on revascularization published by the European Society of Cardiology give a class IIa recommendation and a grade B level of evidence to the use of intravascular ultrasound (IVUS) and optical coherence tomography (OCT) for the optimization of percutaneous coronary interventions (PCI) in selected patients.1 In the case of IVUS, these recommendations are based on multiple studies and meta-analyses that compared the results of angiography vs IVUS-guided PCIs and showed fewer events (including death, infarction or need for new revascularization) with the use of intravascular imaging modalities.2 Guidelines make a specific recommendation on the use of IVUS while performing an angioplasty on the left main coronary artery (class IIa, grade B level of evidence). The other indication for intracoronary imaging modalities established in the guidelines on revascularization is stent failure (class IIa, grade C level of evidence). Several observational studies have proven the utility of IVUS and OCT to detect the causes of thrombosis and restenosis and guide percutaneous treatment.

Q.: Which are the anatomical or clinical contexts with more evidence available?

A.: As I said the clinical context with more evidence available today is the optimization of coronary angioplasty with numerous randomized clinical trials and meta-analyses that confirm the occurrence of fewer events with IVUS-guided PCIs. This effect is especially relevant in the subgroup of patients with complex lesions (including long lesions, bifurcations, and chronic total coronary occlusions) who have a higher risk of events. During the PCI, imaging modalities allow us to determine the size of the stent, optimize its implantation, guarantee its adequate expansion and apposition, and detect possible complications like border dissections.2

The second context with more evidence available (in this case from observational studies) is stent failure. Regarding restenosis, imaging modalities can provide information on its causes (neointimal growth, neoatherosclerosis, underexpansion, disease progression in the stent borders) to determine the most appropriate treatment. Regarding stent thrombosis, intracoronary imaging modalities can detect whether stent thrombosis is due to mechanical causes (like stent underexpansion or incomplete apposition). Also, the OCT allows us to determine whether the cause is associated with an inadequate neointimal coverage of the struts or the rupture of a plaque at the borders or inside the stent.

The anatomical location with highest consensus of all regarding the advantages of using intracoronary imaging modalities (IVUS in particular) is the left main coronary artery. Several studies have proven the utility of this imaging modality to determine the severity of stenosis, the need for revascularization, and eventually to optimize angioplasty.

Q.: Is the IVUS and OCT level of evidence the same?

A.: Since the IVUS has been used much longer than the OCT, there are more clinical studies available on the use of the former, especially as an angioplasty guided imaging modality (to determine the size of the stent and optimize its implantation). However, 2 studies have proven the non-inferiority of OCT vs IVUS for the optimization of stent implantation. The ILUMIEN III study randomized 450 patients who received an OCT, IVUS or angiography-guided angioplasty. It proved the non-inferiority of OCT vs IVUS regarding the minimum stent area obtained. The OPINION study, conducted in Japan, randomized 829 patients to OCT or IVUS-guided stent implantation and proved the non-inferiority of OCT vs IVUS in the primary endpoint of target vessel failure including cardiac death, treated vessel related infarction or new revascularization on the lesion operated on. This prompted that the latest iteration of the revascularization guidelines published by the European Society of Cardiology to give the same class of recommendation (IIa) to the use of IVUS and OCT for PCI optimization.

Q.: What are the advantages of OCT with respect to IVUS during percutaneous coronary interventions?

A.: The OCT has 10 times more resolution than the IVUS, which allows much more detailed visualizations of the arterial wall and its interaction with the stent. This makes it much more sensitive to detect phenomena like stent incomplete apposition or stent border dissection. In the long-term assessment of the stent it also allows us to study the vessel tissue repair and determine whether the stent is completely covered by tissue. Regarding acute coronary syndromes, the OCT is much more sensitive to detect the presence of thrombi and it can characterize the underlying cause much better. In this sense, the OCT allows us to distinguish in vivo acute coronary syndromes due to the rupture of the plaque from those due to erosions, calcified nodules or non-atherosclerotic causes (such as spontaneous coronary artery dissections or embolizations). This is relevant to guide treatment because it can determine whether it is necessary to operate or just use conservative strategy.3

Also, the OCT offers several advantages in the assessment of the causes of stent failure. Regarding in-stent restenosis, it allows us to detect its underlying mechanisms like underexpansion, neointimal tissue growth or disease progressions. Also, the high resolution of this imaging modality has enabled the in vivo detection of neoatherosclerosis as a common cause for restenosis. The analysis of these mechanisms is essential to determine the best therapeutic strategy. For example, in the case of disease progression in the borders of the stent it will be necessary to implant a new stent. However, in cases of stent underexpansion it will be necessary to expand the stent with high pressure dilatations, in some cases, even use plaque modification techniques. If the cause of restenosis is neointimal growth a new stent or a drug-coated balloon can be implanted. Regarding neoatherosclerosis, at the moment there is not enough evidence to determine whether the best strategy is to implant a new stent or use a drug-coated balloon. Still, some data available suggest that both options may be useful.

Regarding stent thrombosis, the OCT allows us to demonstrate in vivo that this is often a multifactor phenomenon and that the cause is not only the lack of stent coverage (as it was initially thought with drug-eluting stents). Instead, it can be due to other factors like neoatherosclerosis with plaques ruptured inside the stent or around its borders, stent underexpansion, incomplete apposition or restenosis. Again, this is an important piece of information to guide the interventional treatment and correct the underlying cause.

Q.: Which cases would be eligible for using IVUS and which for using OCT?

A.: There are 2 anatomical locations where the IVUS is superior compared to the OCT: 1) ostial lesions, due to the impossibility to clean out the blood from the vessel to acquire good images on the OCT; and 2) the left main coronary artery, especially when the ostial segment is involved. Before, the size of the left main coronary artery was a limitation when performing OCT, but with the systems we have today we can see almost all left main coronary arteries unless they are too big. Several studies show the utility of IVUS to assess the severity of the left main coronary artery and for guidance purposes during the angioplasty. At this moment, several studies in the pipeline are assessing the use of OCT while performing angioplasties on the distal left main coronary artery. Probably in the mid and distal left main coronary artery setting, the OCT will be as useful as the IVUS. Maybe even more in the assessment of bifurcations. However, if the ostial segment is involved and we want to see it, we better use the IVUS. Another situation where the IVUS may be preferred over the OCT is to see kidney damage given the need to use contrast for the acquisition of OCT images. In this sense, I should say that the use of contrast can be optimized when performing OCT-guided angioplasties to avoid unnecessary angiographies. A single injection of contrast allows us to perform an angiography and an OCT at the same time. With a single OCT-pullback the reference areas can be selected, and the diameter and length of the vessel can be obtained avoiding the need to perform multiple angiographies.

The OCT is superior to the IVUS and should be the imaging modality of choice to assess stent failure (thrombosis and restenosis) because it is much more precise to determine the underlying mechanism. It is also superior for the assessment of acute coronary syndromes because it is much more sensitive to detect thrombi and distinguish acute coronary syndromes due to plaque rupture from those due to other mechanisms like erosions or non-atherosclerotic causes. The OCT is superior to the IVUS for the assessment of bifurcations because it allows online 3D reconstructions that provide relevant information on the anatomy of the bifurcation and can optimize the angioplasty. An important advantage of the OCT over the IVUS conventional systems is the possibility of a simultaneous registry with an angiography incorporated to the system that does not require the use of any additional software. This facilitates significantly the use of OCT to guide and optimize stent implantation because it offers an online co-registration of the angiographic location of each and every one of the images seen on the OCT.

Q.: What studies are necessary to establish the role of these imaging modalities during percutaneous coronary interventions?

A.: Regarding IVUS, several studies show that its use during the angioplasty can improve the prognosis of patients by reducing the occurrence of events. Regarding the OCT, the primary endpoint of the ILUMIEN IV study, currently in the pipeline, is to show that OCT-guided PCIs can improve stent implantation and reduce clinical events compared to angiography-guided PCIs only. The positive effects of using intracoronary imaging modalities are especially relevant in the subgroup of lesions with higher risk of failure (including long lesions, bifurcations, restenosis, and chronic coronary occlusions). Actually, it is in these patients in whom we should encourage the use of IVUS or OCT.

Beyond the evidence generated in the clinical trials, in order to promote the use of intracoronary imaging modalities, interventional cardiologists need to be trained on how to interpret them. At the same time, imaging systems need to improve to make them easier to use during the procedures. For example, the use of fast systems of image acquisition integrated in the cath lab that allow the operator to use the controls from the table, and co-registration of angiography are some of the tools that can improve the use of these imaging modalities.

Q.: What technical advances are available today or could be available in the near future regarding the OCT?

A.: Among the technical advances currently under research, the most relevant ones have to do with the possibility of estimating and assessing the physiological parameters from OCT acquired 3D reconstructions. This would allow us to use 1 imaging modality only (the OCT) to determine the need to treat and optimize the intervention.

Plaque characterization (especially calcium) using dedicated software is another important field of study. Ultrafast pullbacks will allow us to reduce the amount of contrast needed, and the combination of IVUS plus OCT in the same catheter are other advances being made today.

REFERENCES

QUESTION: Do you think there is enough evidence to indicate the use of intravascular imaging during percutaneous coronary interventions?

ANSWER: The appearance of intracoronary angiography was a major breakthrough for the management of ischemic heart disease. However, the limitations of this imaging modality became evident right from the start. The arrival of intravascular ultrasound (IVUS) 30 years ago now and then the optical coherence tomography (OCT) brought significant advances regarding diagnosis and percutaneous coronary intervention. Although the independent studied that compared IVUS and angiography showed variable results, several meta-analyses1 reinforce the use of the former. On the other hand, although the OCT is much newer compared to the IVUS and there is less scientific evidence supporting it, the excellent quality of its images has turned it into the imaging modality of choice for the management of complex plaques, the detection of complications during the procedure, and the assessment of stent implantation both in the clinical practice and clinical studies.

Q.: Which are the anatomical or clinical contexts with more evidence available?

A.: Both imaging modalities have proven their best cost-effectiveness ratio for the management of complex lesions. In this context, both provide very valuable information in calcified lesions. However, each of them has a specific profile with important differences between the 2.

The left main coronary artery disease is the location where the IVUS has proven most beneficial because it can guide the procedure, but also in long lesions and chronic total occlusions. On the other hand, the effectiveness of IVUS in patients with conditions like diabetes or acute coronary syndrome has been confirmed in former studies.

The excellent quality of the images provided by the OCT makes it very attractive especially in 3 scenarios. In the first place, in cases of acute coronary syndrome where the angiography can show non clearly culprit stenoses, the OCT can detect the presence of dissections, eroded or ruptured plaques, small thrombi or vessel wall hematomas. The second scenario is in-stent restenosis, where it can identify underlying mechanisms like underexpansion, hyperplasia and neoatherosclerosis. Finally, it is the imaging modality of choice to study stent endothelization, a very important aspect if it can be relevant enough as to decide on the continuity or not of antiplatelet therapy and, above all, in the context of clinical studies

Q.: Is the IVUS and OCT level of evidence the same?

A.: To this day, and partly due to the fact that IVUS has been with us much longer, its scientific evidence is more solid since the OCT has less often been compared to the angiography and only to IVUS in a clinical trial.2 As a consequence, the clinical practice guidelines3 show the current scientific evidence available in the following recommendations and levels of evidence:

Q.: What are the advantages of OCT with respect to IVUS during percutaneous coronary interventions?

A.: Although the IVUS has 10 times less resolution than the OCT and, therefore, worse image quality, it is superior to the OCT in some aspects. The IVUS has a greater capacity to penetrate soft tissues (5-6 mm vs 1-2 mm of the OCT) and detects the total thickness of the vessel, which is an advantage when having to decide on the diameter of the stent in relation to the size of the vessel. Its second greatest advantage is that it does not require washing the artery to eliminate the red blood cells that complicate the performance of an OCT so much. Finally, in certain patients, especially those with left main coronary artery disease, and since no artery washing is required, both scientific evidence and image quality make IVUS the imaging modality of choice.

Q.: Which cases would be eligible for using IVUS and which for using OCT?

A.: The characteristics of the patient and the lesion condition the use of 1 imaging modality over the other. For example, IVUS is more adequate in cases of:

In the remaining scenarios, the superior image quality provided by the OCT is a very significant advantage, which means that it is the imaging modality of choice when the aforementioned situations don’t take place.

There is a subgroup of lesions where the OCT has become very popular. I am talking about bifurcations that amount to 15% of all the percutaneous coronary interventions performed these days. The use of intravascular imaging is highly recommended here since they are lesions with an associated higher rate of thrombosis and restenosis. Besides, the latter is difficult to treat, and a top level of excellence is advised in the results obtained that can be optimized with the use of imaging modalities, especially OCT. Having said this, we should always remember the limitation imposed by the use of additional contrast at the end of a complex case. Therfore, despite the fact that the image quality of IVUS is worse compared to OCT, at times it can replace it. The recent advances made in the design of new higher-resolution IVUS catheters can be an alternative to bear in mind when the use of OCT is somehow problematic.

Q.: What studies are necessary to establish the role of these imaging modalities during percutaneous coronary interventions?

A.: Since the left main coronary artery is the location where IVUS performs better and taking into consideration the current class IIa recommendation with grade B level of evidence, it would be very interesting to have studies available that would enable an upgrade to a class I recommendation. Regarding the left main coronary artery disease, these studies can also be very interesting for another reason. For example, the EXCEL and NOBLE clinical trials are no longer producing more evidence on the percutaneous revascularization of these patients. This means that «something new» should come up if we want to show additional benefits to be able to upgrade the levels of recommendations and evidence. Examples of these trials in the pipeline are (ClinicalTrials.gov):

On the other hand, the situation with the OCT is different. This imaging modality has grown rapidly thanks to its excellent image quality. However, scientific support is not as strong. Added to the studies where this imaging modality is not the study primary endpoint but the tool to show the primary endpoint in subgroups of patients (acute coronary syndrome with or without ST-segment elevation and studies focused on the results of certain stents), it would be interesting to conduct clinical trials on the OCT. These studies primary endpoint would be to improve clinical results to increase the level of recommendation published by the guidelines. An example of this type of studies is the ILUMIEN IV: OPTIMAL PCI NCT03507777 where 3656 patients will be randomized in a 1:1 ratio to compare the result of angiography vs OCT-guided stenting at a 2-year follow-up.

Q.: What technical advances are available today or could be available in the near future regarding the OCT?

A.: Over the last few years, the following advances have been made regarding IVUS, some of them are still in the pipeline.

REFERENCES

QUESTION: After the IABP-SHOCK II clinical trial, which would you say is the utility of the intra-aortic balloon pump (IABP)?

ANSWER: The IABP-SHOCK II1 did not show any benefits in the 30-day mortality rate or major complications rate when the IABP was compared to conventional therapy in patients with post-infarction cardiogenic shock undergoing primary percutaneous coronary intervention (PCI). No differences were found either in the mortality rate or quality of life of survivors in the studies conducted at 12-month2 and 6 year-follow-up.3

European guidelines4 downgraded the systematic use of IABP to a class IIIb level of evidence leaving the indication IIa for the management of infarct related mechanical complications. This decreased the use of IABP in the routine clinical practice. However, it is still used in critical care units because it is easy to use, can be implanted quickly, and is cheaper compared to other devices.

Taking into account the limitations of these studies and although we do not use it systematically in our center like we used to years ago, we still implant it as the first-line strategy for the management of infarct related mechanical complications. Also, in patients with extensive acute myocardial infarction (IAM) and hemodynamic instability because it improves coronary perfusion and increases the cardiac output.

Q.: In the congress held by the American Heart Association back in 2019 several observational registries showed more adverse events and higher costs compared with the use of the Impella device compared to the IABP. However, these results may be due to the effect of multiple biases. What do you think of all this?

A.: These observational registries revealed a higher rate of adverse events, and higher costs associated with the use of the Impella device compared to the IABP. However, they have some limitations: they mixed different types of Impella devices (2.5, CP, and 5) and different etiologies of cardiogenic shock. Also, in most of the patients the device was implanted after the primary percutaneous coronary intervention. In one of these registries that would later be published in Circulation,5 patients implanted electively with the Impella device in the cardiogenic shock setting were also included.

We have been getting more and more data that the management of cardiogenic shock through the creation of specialized units, invasive hemodynamic monitorization, and implantation of the Impella CP device prior to the PCI improves the results of revascularization and reduces the size of the infarction and the 30-day mortality rate in patients with post-infarction cardiogenic shock. Some studies like the Detroit shock initiative6 and the national cardiogenic shock initiative7 have already discussed this theory.

Currently, several randomized clinical trials are trying to come to terms with this hypothesis: the Danger shock trial8 (support with Impella CP prior to the PCI vs conventional therapy in the management of post-infarction cardiogenic shock), the RECOVER IV (Impella before PCI vs PCI without Impella in the management of infarction related cardiogenic shock), and the STEMI DTU (ClinicalTRials.gov NCT03947619) (Impella CP and PCI delayed 30 min. vs immediate PCI in patients with ST-segment elevation acute myocardial infarction of anterior location without shock). The latter is based on the results from a pilot study on safety and feasibility. The DTU-STEMI pilot trial9 proved that it is safe and feasible to perform a PCI 30 min. after LV (left ventricular) unloading with the Impella CP device in patients with anterior AMI without shock.

Regarding high-risk PCIs, the PROTECT-II trial10 that randomized 452 patients who underwent high-risk PCIs with IABP or Impella 2.5 support showed no differences in the cardiovascular events occurred at the 30- and 90-day follow-up. However, fewer adverse events were seen at the 90-day follow-up in the Impella 2.5 group.

The PROTECT IV study is underway (Impella as support for high-risk PCI vs PCI without hemodynamic support). It will start in 2021 and it will be part of the clinical evidence for the class I recommendation for the Impella device in high-risk PCIs.

The results of the studies currently underway are promising because I think it is LV unloading prior to the PCI that will certainly improve the mortality of post-infarction cardiogenic shock. To this day and until proven wrong, I strongly believe that the Impella CP implanted prior to the PCI is the device of choice for the management of post-infarction cardiogenic shock.

Until we have more data available, I think high-risk PCIs should be handled individually based on the characteristics of the patients and the experience of the heart teams with these devices and in the management of complex PCIs.

Q.: Is your center savvy in the use of extracorporeal membrane oxygenation (ECMO)? What evidence exists for its use in the management of cardiogenic shock in patients with infarction? What studies would be needed in this context to consolidate its indication?

A.: Some of the advantages of the ECMO device are that it is easy to use and can be implanted quickly. Its main hemodynamic effect is an increased mean arterial blood pressure that is higher compared to other devices. However, this advantage is precisely the cause for its most important limitation: the problem of LV unloading in relation to an increased afterload. This increases myocardial oxygen demand and produces deleterious effects on the size of the infarction and its potential recovery. From the pathophysiological point of view, it is not a good device for the management of post-infarction cardiogenic shock.11 Its basic role rests in its hemodynamic effect and improved organ perfusion; that is, it is indicated for patients in INTERMACS 1 situation. To overcome the limitation of inadequate LV unloading, the best option is to add an Impella device that is capable of producing the most powerful hemodynamic effect for LV unloading in ECMO.12

Our center is highly experienced in the use of ECMO for the management of cardiogenic shock of any known etiology. We use it for the management of patients with post-infarction deep cardiogenic shock (INTERMACS 1) in the coronary care unit before or after the primary percutaneous coronary intervention. In these patients we initially implant the IABP to improve LV unloading. If the balloon is insufficient, the next step is to add an Impella device.

There are no randomized studies available on the use of ECMO for the management of post-infarction cardiogenic shock. We’ll have to wait for the results from other devices. If the hypotheses formulated prove right, ECMO will play a significant role in the management of patients with AMI in whom the Impella device is insufficient or in hospitalized patients with hemodynamic compromise used in combination with the Impella device to overcome the limitation of inadequate ventricular unloading.

Q.: What escalation of mechanical circulatory support do you recommend in hemodynamically compromised patients or patients with post-infarction shock?

A.: I think the first thing to do is to include cardiogenic shock in specialized units experienced in the management of these patients and use of this type of devices. The right selection of patients, invasive hemodynamic monitorization, and use of inotropes for stabilization purposes is of paramount importance until early device implantation.

With the current data and taking into account the costs of the different devices and the complications associated there are different considerations to be made when choosing one device over the other:

–Patients with extensive infarction and pre-shock, mechanical complications or ventricular arrhythmias: IABP.

–Patients without deep shock (INTERMACS 2): Impella CP prior to the percutaneous coronary intervention and, if not enough support is achieved, add ECMO.

–Patients in deep shock (INTERMACS 1): ECMO combined with balloon or Impella device if there are problems unloading the left ventricle.

CONFLICTS OF INTEREST

None reported.

Corresponding author: Unidad de Cardiología-Críticos, Pabellón 17-1, Hospital Universitario Marqués de Valdecilla, Avda. Valdecilla s/n, 39008 Santander, Cantabria, Spain. E-mail address: Jacobina_2@hotmail.com (V. Burgos Palacios).

REFERENCES

QUESTION: After the IABP-SHOCK II clinical trial, which would you say is the utility of the intra-aortic balloon pump (IABP)?

ANSWER: In my opinion and yet despite the results of the IABP-SHOCK II,1 the intra-aortic balloon pump (IABP) still plays a significant role in the management of acute myocardial infarction (AMI) and complex percutaneous coronary intervention (PCI) with risks higher than normal.

In high-risk PCIs there is evidence of the benefits derived from using left ventricular assist devices. In the first place, the IABP has shown late benefits in the BCIS-I trial.2 This study randomized patients treated with high-risk PCI—defined as a left ventricular ejection fraction < 30% and > 40% of the lesion related myocardium with intention-to-treat—assessed using scores ≥ 8 in the Jeopardy score. The early study found no significant differences in the primary endpoint at the 28-day follow-up. In the secondary endpoint a numerical difference was found in the mortality rate at the 6-month follow-up, although it was not statistically significant (4.6 in the IABP vs 7.4% in the control group; P = .32) probably due to the low number of patients included (301). However, at the 51-month follow-up,3 the mortality rate was significantly higher in the control group: 38% (12.1/100 patients/year) vs 27.8% (7.9/100 patients/year). The Kaplan-Meier curves showed a significant difference with a hazard ratio of 0.66 (95% confidence interval, 0.44-0.98; P = .039). In our routine clinical practice, patients undergoing high-risk PCI (left main coronary artery with occluded right coronary artery, multivessel disease with depressed left ventricular function) without a technically complex lesion are treated with IABP support.

On the other hand, in the management of AMI there is no doubt that in the presence of mechanical complications like acute mitral regurgitation or interventricular communication, the IABP improves the patient’s condition as long as he is not in a situation of deep cardiogenic shock. This stabilizes the patient until he is in a better condition to undergo definitive surgery.

In the management of AMIs complicated with cardiogenic shock, the role of the IABP would be limited when the shock has already occurred. However, it may be useful for the early management of those stages when the patient is in a high-risk situation and is starting to show hemodynamic impairment (certain degree of hypotension and tachycardia, but no signs of poor target organ perfusion) to achieve an early stabilization. This is so because it is easy to implant in any critical care unit without having to transfer the patient, and thanks to its safety profile confirmed by its low rate of complications.

Q.: In the congress held by the American Heart Association back in 2019 several observational registries showed more adverse events and higher costs compared with the use of the Impella device compared to the IABP. However, these results may be due to the effect of multiple biases. What do you think of all this?

A.: These studies have been published in JAMA and provide different data on the management of patients with post-infarction cardiogenic shock in a retrospective registry.4 This was a very large registry of patients with different baseline characteristics despite the fact that propensity score matching was used. After a thorough reading and analysis of the final outcomes, the mortality rate of the group treated with IABP was clearly lower compared to the one reported by randomized studies on the management of AMI with cardiogenic shock. This is indicative of an early selection bias since it was not a randomized study. However, the group treated with a micro-axial pump had a similar mortality rate compared to the one described by the studies.

We should mention that neither one of the 2 devices showed clinical benefits in this situation compared to standard treatment. This means that the only information provided by that registry is that the least critically ill patients receive an IABP while the most critically ill ones receive a micro-axial flow device. The final outcome shows this early selection bias.

Q.: What is the evidence available on the use of the Impella device in high-risk interventional cardiac procedures? What is the routine clinical practice in your center? And in patients with infarction and cardiogenic shock?

A.: The Impella device has proven useful for the management of high-risk PCIs in the PROTECT II trial.5 This study randomized patients undergoing high-risk PCIs—defined as left main coronary artery disease or last patent vessel disease with an ejection fraction ≤ 35% or 3-vessel disease with an ejection fraction ≤ 30%—eligible to receive an IABP circulatory support device or an Impella 2.5 device. Regarding major cardiovascular events (all-cause mortality, myocardial infarction, stroke or new revascularization), the Impella 2.5 device obtained better results and even showed preventive properties in a multivariate study. If we analyze the study data thoroughly, we can see that its greatest advantage was the lower rate of new revascularizations in part due to the fact that with the Impella device we can treat more complex lesions during the index procedure.

In light of the results from these studies our indications for ventricular support in patients undergoing elective or high-risk PCIs (severe ventricular dysfunction with left main coronary artery disease plus right coronary artery occlusion or 3-vessel disease) are:

 

 

Q.: What escalation of mechanical circulatory support do you recommend in hemodynamically compromised patients or patients with post-infarction cardiogenic shock?

A.: The definition and fast detection of patients who have suffered an AMI is very important. In this sense, the Society for Cardiovascular Angiography and Intervention (SCAI) proposed a new classification of patients after AMI with a series of clinical, analytic, and hemodynamic criteria.6 This classification in stages has proven that there is a clinical correlation with the mortality rates shown by these patients.7 Thus, the stages of hemodynamic impairment can be described as:

 

 

Currently, there are different types of hemodynamic support with different characteristics regarding the mechanism of action and the effects it has on the heart and coronary circulation.8 Every device offers different hemodynamic support and is associated with a different rate of complications. That is why the risk-benefit ratio should be taken into consideration depending on each patient’s hemodynamic impairment. In my view, the different devices may be indicated for the following stages:

 

 

In general, the degree of support required may be defined in a different way:

 

 

CONFLICTS OF INTEREST

J. A. Gómez Hospital has received funding from Izasa Hospitals for his collaboration in the implantation of Impella devices and organizing sessions on left ventricular support.