Clinical scenarios for use of transvalvular microaxial pumps in acute heart failure and cardiogenic shock - A European experienced users working group opinion

Review of Advancements in Managing Cardiogenic Shock: From Emergency Care Protocols to Long-Term Therapeutic Strategies

Cardiogenic shock (CS) is a complex multifactorial clinical syndrome of end-organ hypoperfusion that could be associated with multisystem organ failure, presenting a diverse range of causes and symptoms. Despite improving survival in recent years due to new advancements, CS still carries a high risk of severe morbidity and mortality. Recent research has focused on improving early detection and understanding of CS through standardized team approaches, detailed hemodynamic assessment, and selective use of temporary mechanical circulatory support devices, leading to better patient outcomes. This review examines CS pathophysiology, emerging classifications, current drug and device therapies, standardized team management strategies, and regionalized care systems aimed at optimizing shock outcomes. Furthermore, we identify gaps in knowledge and outline future research needs.

Structured Weaning From the Impella Left Ventricular Micro-Axial Pump in Acute Myocardial Infarction With Cardiogenic Shock and Protected Percutaneous Coronary Intervention: Experience From a Non-Cardiac Surgical Centre

BACKGROUND

The Impella (Abiomed, Danvers, MA, USA) temporary percutaneous left ventricular assist device is increasingly used as mechanical circulatory support in patients with acute myocardial infarction-cardiogenic shock (AMICS) or those undergoing high-risk protected percutaneous coronary intervention (PCI). The optimal weaning regimen remains to be defined.

METHOD

We implemented a structured weaning protocol in a series of 10 consecutive patients receiving Impella support for protected PCI or AMICS treated with PCI in a high volume non-cardiac surgery centre. Weaning after revascularisation was titrated to native heart recovery using both haemodynamic and echocardiographic parameters.

RESULTS

Ten patients (eight male, two female; aged 43-70 years) received Impella support for AMICS (80%) or protected PCI (20%). Cardiogenic shock was of Society for Cardiac Angiography & Interventions grade C-E of severity in 80%, and median left ventricular end-diastolic pressure was 31 mmHg. Protocol implementation allowed successful weaning in eight of 10 patients with a median support time of 29 hours (range, 4-48 hours). Explantation was associated with an increase in heart rate (81 vs 88 bpm; p=0.005), but no significant change in Cardiac Index (2.9 vs 2.9 L/min/m2), mean arterial pressure (79 vs 82 mmHg), vasopressor requirement (10% vs 10%), or serum lactate (1.0 vs 1.0). Median durations of intensive care and hospital stay were 3 and 6 days, respectively. At 30 days, the mortality rate was 20%, with median left ventricular ejection fraction of 40%.

CONCLUSIONS

A structured and dynamic weaning protocol for patients with AMICS and protected PCI supported by the Impella device is feasible in a non-cardiac surgery centre. Larger studies are needed to assess generalisability of such a weaning protocol.

Novel therapeutic strategies to reduce reperfusion injury after acute myocardial infarction

For almost 30 years, urgent revascularization termed primary percutaneous coronary intervention (pPCI) has been a cornerstone of modern care for acute myocardial infarction (AMI). It lowers mortality and improved cardiovascular outcome compared to conservative therapy including thrombolysis. Reperfusion injury, which occurs after successful re-opening of the formerly occluded coronary artery, had been exploited as a potential therapeutic target. When revascularisation became faster and pPCI was successfully performed within 60-90 minutes of symptom onset, the interest in a potential additive effect of targeting reperfusion injury vanished. More recently, several meta-analyses indicated that limiting reperfusion injury prevents microvascular obstruction and reduces final infarct size, thereby lowering the probability of heart failure events and improving quality of life in AMI survivors. Here, we describe the current strategies to limit reperfusion injury and to improve post-AMI outcomes such as systemic or intracoronary hypothermia, left-ventricular unloading, intracoronary infusion of super-saturated oxygen, intermittent coronary sinus occlusion, and C-reactive protein apharesis.

Akute Herzinsuffizienz und kardiogener Schock – Bedeutung der ECLS

Der kardiogene Schock (CS) stellt den schwersten Verlauf einer akuten Herzinsuffizienz (AHF) mit exzessiven Letalitätsraten von bis zu 50% dar. Bei refraktärem Verlauf bieten temporäre mechanische Kreislaufunterstützungssysteme eine wertvolle Therapieoption. Insbesondere die ECLS-Therapie (extracorporeal life support) wird dem klinischen Bedarf entsprechend, trotz bislang fehlender Evidenz aus randomisiert-kontrollierten Studien, zunehmend häufiger bei CS eingesetzt. Vor diesem Hintergrund muss die ECLS-Indikation weiterhin unter kritischer Nutzen-Risiko-Abwägung und unter Berücksichtigung objektiver hämodynamischer sowie patientenbezogener klinischer Parameter gestellt werden. Aktuelle Leitlinien empfehlen ferner die Etablierung von CS-Zentren mit strukturierten Therapiekonzepten und eingespielten Teams. In diesem Artikel werden grundlegende pathophysiologische Konzepte und Therapieansätze der AHF und des CS beleuchtet und der Stellenwert der ECLS in diesem Setting eingeordnet.

Anticoagulation for Percutaneous Ventricular Assist Device-Supported Cardiogenic Shock: JACC Review Topic of the Week

Interest in the use of mechanical circulatory support for patients presenting with cardiogenic shock is growing rapidly. The Impella (Abiomed Inc), a microaxial, continuous-flow, short-term, ventricular assist device (VAD), requires meticulous postimplantation management. Because systemic anticoagulation is needed to prevent pump thrombosis, patients are exposed to increased bleeding risk, further aggravated by sepsis, thrombocytopenia, and high shear stress-induced acquired von Willebrand syndrome. The precarious balance between bleeding and thrombosis in percutaneous VAD-supported cardiogenic shock patients is often the main reason that patient outcomes are jeopardized, and there is a lack of data addressing optimal anticoagulation management strategies during percutaneous VAD support. Here, we present a parallel anti-Factor Xa/activated partial thromboplastin time-guided anticoagulation algorithm and discuss pitfalls of heparin monitoring in critically ill patients. This review will guide physicians toward a more standardized (anti)coagulation approach to tackle device-related morbidity and mortality in this critically ill patient group.

Percutaneous Transvalvular Microaxial Flow Pump Support in Cardiology

The Impella device (Impella, Abiomed, Danvers, MA) is a percutaneous transvalvular microaxial flow pump that is currently used for (1) cardiogenic shock, (2) left ventricular unloading (combination of venoarterial extracorporeal membrane oxygenation and Impella concept), (3) high-risk percutaneous coronary interventions, (4) ablation of ventricular tachycardia, and (5) treatment of right ventricular failure. Impella-assisted forward blood flow increased mean arterial pressure and cardiac output, peripheral tissue perfusion, and coronary blood flow in observational studies and some randomized trials. However, because of the need for large-bore femoral access (14 F for the commonly used Impella CP device) and anticoagulation, the incidences of bleeding and ischemic complications are as much as 44% and 18%, respectively. Hemolysis is reported in as many as 32% of patients and stroke in as many as 13%. Despite the rapidly growing use of the Impella device, there are still insufficient data on its effect on outcome and complications on the basis of large, adequately powered randomized controlled trials. The only 2 small and also underpowered randomized controlled trials in cardiogenic shock comparing Impella versus intra-aortic balloon pump did not show improved mortality. Several larger randomized controlled trials are currently recruiting patients or are in preparation in cardiogenic shock (DanGer Shock [Danish-German Cardiogenic Shock Trial; NCT01633502]), left ventricular unloading (DTU-STEMI [Door-To-Unload in ST-Segment-Elevation Myocardial Infarction; NCT03947619], UNLOAD ECMO [Left Ventricular Unloading to Improve Outcome in Cardiogenic Shock Patients on VA-ECMO], and REVERSE [A Prospective Randomised Trial of Early LV Venting Using Impella CP for Recovery in Patients With Cardiogenic Shock Managed With VA ECMO; NCT03431467]) and high-risk percutaneous coronary intervention (PROTECT IV [Impella-Supported PCI in High-Risk Patients With Complex Coronary Artery Disease and Reduced Left Ventricular Function; NCT04763200]).

Multimodal temporary mechanically circulatory assistance for primary graft dysfunction after heart transplantation: a case report

Background

Primary graft dysfunction (PGD) remains a serious complication after heart transplantation (HTx). Although there is no therapy available, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) may be a bailout strategy in selected cases. Especially in patients with severe biventricular failure, chances of survival remain poor.

Case summary

Here, we report a case of a 56-year-old patient suffering from severe PGD after HTx with biventricular failure (ejection fraction < 20%) who was successfully bridged to recovery of the donor graft by temporary multimodal mechanically circulatory assistance by combining both, VA-ECMO and a microaxial pump (Impella^®, Abiomed, Inc., Danvers, MA, USA), a concept also referred as ECMELLA. During ECMELLA support, the patient experienced multiple severe thoracic bleeding complications with need for four re-thoracotomies and temporary open chest situation. Nevertheless, ventricular function recovered and the patient could be weaned from mechanical circulatory support after 12 days. During follow-up, the patient recovered and was successfully discharged. After the following rehabilitation, the patient now shows no persistent signs of heart failure with normal biventricular function of the cardiac graft.

Discussion

ECMELLA may offer a therapeutic option for patients with severe PGD after HTx. Special awareness and further studies addressing targeted anticoagulation strategies for patients on dual-mechanical support are needed to diminish the incidence of bleeding complications.

Temporary mechanical circulatory support in cardiogenic shock

Cardiogenic shock (CS) represents one of the foremost concerns in the field of acute cardiovascular medicine. Despite major advances in treatment, mortality of CS remains high. International societies recommend the development of expert CS centers with standardized protocols for CS diagnosis and treatment. In these terms, devices for temporary mechanical circulatory support (MCS) can be used to support the compromised circulation and could improve clinical outcome in selected patient populations presenting with CS. In the past years, we have witnessed an immense increase in the utilization of MCS devices to improve the clinical problem of low cardiac output. Although some treatment guidelines include the use of temporary MCS up to now no large randomized controlled trial confirmed a reduction in mortality in CS patients after MCS and additional research evidence is necessary to fully comprehend the clinical value of MCS in CS. In this article, we provide an overview of the most important diagnostic and therapeutic modalities in CS with the main focus on contemporary MCS devices, current state of art and scientific evidence for its clinical application and outline directions of future research efforts.

Temporary extracorporeal femoro-femoral crossover bypass to treat acute limb ischemia due to occlusive femoral transaortic microaxial left ventricular assist device - A novel technique and case series

BACKGROUND

The Impella transaortic microaxial left ventricular assist device (MLVAD) bears the risk of severe ipsilateral limb ischemia due to its percutaneous insertion through the common femoral artery (CFA). As long as the MLVAD is required for cardio - circulatory support, treatment options are limited. Therefore, we developed a temporary extracorporeal femoral - femoral crossover bypass to restore and maintain perfusion of the affected leg.

METHODS

From October 2018, we treated all patients with severe limb ischemia due to the MLAVD with a femoral - femoral crossover bypass. For comparison, a consecutive cohort of patients undergoing placement of the MLAVD between January 2011 and October 2018 was identified. The primary outcome is the feasibility and safety of our percutaneously established extracorporeal femoral - femoral crossover bypass.

RESULTS

Between January 2011 and July 2019, 25 of 245 (10.3%) patients developed a severe ipsilateral limb ischemia following the MLVAD placement. Until October 2018, 20 patients were treated conventionally (C - cohort) and since October 2018, five (consecutive) patients have been treated by an extracorporeal femoral - femoral cross over bypass (BP - Cohort). Following the BP - procedure, an immediate improvement of the perfusion was seen in all patients. Limb salvage was documented in 100% of our patients and 30 - day mortality was 60% in both groups.

CONCLUSION

This is the first case series reporting on this novel technique. We demonstrated that the percutaneous creation of an extracorporeal crossover bypass is feasible, safe and effective and should therefore be promoted.

How Would the Authors Treat Their Own Temporary Left Ventricular Failure With Mechanical Circulatory Support?

In the last 20 years, mechanical circulatory supports (MCS) have overturned completely the outcomes and the clinical recovery of patients with isolated acute left ventricle failure (iALVF). This usually occurs more frequently than right-sided heart failure or biventricular dysfunction, and it mainly is caused by acute myocardial infarction. The primary role of MCS is to restore the tissue metabolism to preserve the vital organs' function but, on the other hand, they also have to relieve the workload stress on the heart. In this way, they allow not only the heart to recover from the acute event, but MCS also can stabilize the patient toward cardiac transplantation. The short-term MCS devices currently used in clinical practice are the intraaortic balloon pump, the Impella (Abiomed, Danvers, MA), and venoarterial extracorporeal membrane oxygenation (VA-ECMO), but the choice of the right and tailored device for each patient, as well as the timing to use it, is actually one of the most debated topics of MCS management.

Combined extracorporeal membrane oxygenation and microaxial pump-when left ventricular preload is too low to unload in cardiogenic shock

PURPOSE

Severe cardiogenic shock is the major driver of mortality on cardiologic intensive care units. Novel therapeutic options like extracorporeal membrane oxygenation (ECMO) or the combination of ECMO and a percutaneous microaxial pump like Impella CP (ECMELLA) are promising Options. Here we want to focus on the question what happens when left ventricular preload is too low to unload in cardiogenic shock in patients with ECMELLA and this aspect is illustrated by transesophageal echocardiography.

METHODS

We detail a case of a 43-year-old active smoker who was admitted for acute myocardial infarction causing severe cardiogenic shock and who was finally treated with ECMELLA. Transesophageal echocardiography is used to illustrate what happens when left ventricle (LV) preload is too low to unload.

RESULTS

Transesophageal echocardiography demonstrates complete collapse of LV and LA as consequence of increased but still low flow rate of the coaxial pump.

CONCLUSION

Novel therapeutic options like ECMO and percutaneous microaxial pumps like Impella CP, 5.0 or the combination of both (ECMELLA), are promising options. Whether these approaches reduce mortality has to be evaluated in urgently needed randomized trials but results will not be available in the next few years.

Management of cardiogenic shock

Despite the rapidly evolving evidence base in modern cardiology, progress in the area of cardiogenic shock remains slow, with short-term mortality still reaching 40-50%, relatively unchanged in recent years. Despite advances with an increase in the number of clinical trials taking place in this admittedly difficult-to-study area, the evidence base on which we make day-to-day decisions in clinical practice remains relatively sparse. With only definitive evidence for early revascularisation and the relative ineffectiveness of intra-aortic balloon pumping, most aspects of patient management are based on expert consensus, rather than randomised controlled trials. This updated 2020 review will outline the management of CS mainly after acute myocardial infarction with major focus on state-of-the-art treatment based on randomised clinical trials or matched comparisons if available.

Unloading in Refractory Cardiogenic Shock After Out-Of-Hospital Cardiac Arrest Due to Acute Myocardial Infarction-A Propensity Score-Matched Analysis

Aims: Unclear neurological outcome often precludes severely compromised patients after out-of-hospital cardiac arrest (OHCA) from mechanical circulatory support (MCS), while it may be considered as rescue therapy for patients with refractory cardiogenic shock (rCS) in the absence of OHCA. This analysis sought to investigate the role of left ventricular (LV) unloading in patients with rCS related to acute myocardial infarction (AMI) after OHCA. Methods: Of 273 consecutive patients receiving microaxial pumps in the Hannover Cardiac Unloading Registry between January 2013 and August 2018, 47 presented with AMI-rCS following successful resuscitation. Subsequently, the patients were compared by propensity score matching to patients with OHCA AMI-rCS without MCS. The patient data for OHCA without LV unloading was available from 280 patients of the Hannover Cooling Registry for the same time period. Furthermore, the patients with OHCA without rCS were compared to the patients with OHCA AMI-rCS and LV unloading. Results: In total, 15 OHCA AMI-rCS patients without MCS were matched to patients with AMI-rCS and Impella. Patients without LV support had a higher proportion of a cardiac cause of death (n = 7 vs. n = 3; p = 0.024). LV unloading with Impella counteract rCS status and was associated with a preferable 30-day survival (66.7 vs. 20%, p = 0.01) and a favorable neurological outcome after 30 days (Cerebral Performance Category ≤2, 47 vs. 27%). Impella support is associated with a higher 30-day survival (odds ratio, 2.67; 95% confidence interval, 1.02-13.66). Conclusion: In patients after OHCA with AMI-rCS, Impella support incorporated in a strict standardized treatment algorithm results in a preferable 30-day survival and counteracts severe rCS status.

Complete Revascularisation in Impella-Supported Infarct-Related Cardiogenic Shock Patients Is Associated With Improved Mortality

Background: Acute myocardial infarction-related cardiogenic shock (AMI-CS) still has high likelihood of in-hospital mortality. The only trial evidence currently available for the intra-aortic balloon pump showed no benefit of its routine use in AMI-CS. While a potential benefit of complete revascularisation has been suggested in urgent revascularisation, the CULPRIT-SHOCK trial demonstrated no benefit of multivessel compared to culprit-lesion only revascularisation in AMI-CS. However, mechanical circulatory support was only used in a minority of patients. Objectives: We hypothesised that more complete revascularisation facilitated by Impella support is related to lower mortality in AMI-CS patients. Methods: We analysed data from 202 consecutive Impella-treated AMI-CS patients at four European high-volume shock centres (age 66 ± 11 years, 83% male). Forty-seven percentage (n = 94) had cardiac arrest before Impella implantation. Revascularisation was categorised as incomplete if residual SYNTAX-score (rS) was >8. Results: Overall 30-day mortality was 47%. Mortality was higher when Impella was implanted post-PCI (Impella-post-PCI: 57%, Impella-pre-PCI: 38%, p = 0.0053) and if revascularisation was incomplete (rS ≤ 8: 37%, rS > 8: 56%, p = 0.0099). Patients with both pre-PCI Impella implantation and complete revascularisation had significantly lower mortality (33%) than those with incomplete revascularisation and implantation post PCI (72%, p < 0.001). Conclusions: Our retrospective analysis suggests that complete revascularisation supported by an Impella microaxial pump implanted prior to PCI is associated with lower mortality than incomplete revascularisation in patients with AMI-CS.

Prevention and treatment of pulmonary congestion in patients undergoing venoarterial extracorporeal membrane oxygenation for cardiogenic shock

Cardiogenic shock is still a major driver of mortality on intensive care units and complicates ∼10% of acute coronary syndromes with contemporary mortality rates up to 50%. In the meantime, percutaneous circulatory support devices, in particular venoarterial extracorporeal membrane oxygenation (VA-ECMO), have emerged as an established salvage intervention for patients in cardiogenic shock. Venoarterial extracorporeal membrane oxygenation provides temporary circulatory support until other treatments are effective and enables recovery or serves as a bridge to ventricular assist devices, heart transplantation, or decision-making. In this critical care perspective, we provide a concise overview of VA-ECMO utilization in cardiogenic shock, considering rationale, critical care management, as well as weaning aspects. We supplement previous literature by focusing on therapeutic issues related to the vicious circle of retrograde aortic VA-ECMO flow, increased left ventricular (LV) afterload, insufficient LV unloading, and severe pulmonary congestion limiting prognosis in a relevant proportion of patients receiving VA-ECMO treatment. We will outline different modifications in percutaneous mechanical circulatory support to meet this challenge. Besides a strategy of running ECMO at lowest possible flow rates, novel therapeutic options including the combination of VA-ECMO with percutaneous microaxial pumps or implementation of a venoarteriovenous-ECMO configuration based on an additional venous cannula supplying towards pulmonary circulation are most promising among LV unloading and venting strategies. The latter may even combine the advantages of venovenous and venoarterial ECMO therapy, providing potent respiratory and circulatory support at the same time. However, whether VA-ECMO can reduce mortality has to be evaluated in the urgently needed, ongoing prospective randomized studies EURO-SHOCK (NCT03813134), ANCHOR (NCT04184635), and ECLS-SHOCK (NCT03637205). These studies will provide the opportunity to investigate indication, mode, and effect of LV unloading in dedicated sub-analyses. In future, the Heart Teams should aim at conducting a dedicated randomized trial comparing VA-ECMO support with vs. without LV unloading strategies in patients with cardiogenic shock.

New challenges in cardiac intensive care units

Critical care cardiology is a steadily and rapidly developing sub-specialization within cardiovascular medicine, since the first emergence of a coronary care unit in the early 1960s. Today, modern cardiac intensive care units (CICU) serve a complex patient population with a high burden of cardiovascular and non-cardiovascular critical illnesses. Treatment of these patients requires a multidisciplinary approach, with a combination of highly specialized knowledge and skills in cardiovascular diseases, as well as emergency, critical-care and internal medicine. The CICU has always posed special challenges to both experienced intensivists as well as fellows-in-training (FIT) and is certainly one of the most demanding training phases. In recent years, these challenges have grown significantly owing to technological innovations, with new and steadily rising numbers of complex interventional procedures and new options for temporary circulatory support for critically ill patients, such as venoarterial extracorporeal membrane oxygenation (VA-ECMO). Herein, we focus on the successful CICU management of these special patient cohorts, which must become an integral part of critical-care training.

Neuromarkers and neurological outcome in out-of-hospital cardiac arrest patients treated with therapeutic hypothermia-experience from the HAnnover COoling REgistry (HACORE)

Background

Neuron-specific enolase (NSE) and S-100b have been used to assess neurological damage following out-of-hospital cardiac arrest (OHCA). Cut-offs were derived from small normothermic cohorts. Whether similar cut-offs apply to patients treated with hypothermia remained undetermined.

Methods

We investigated 251 patients with OHCA treated with hypothermia but without routine prognostication. Neuromarkers were determined at day 3, neurological outcome was assessed after hospital discharge by cerebral performance category (CPC).

Results

Good neurological outcome (CPC≤2) was achieved in 41%. Elevated neuromarkers, older age and absence of ST-segment elevation after ROSC were associated with increased mortality. Poor neurological outcome in survivors was additionally associated with history of cerebrovascular events, sepsis and higher admission lactate. Mean NSE was 33μg/l [16–94] vs. 119μg/l [25–406]; p<0.001, for survivors vs. non-survivors, and 21μg/l [16–29] vs. 40μg/l [23–98], p<0.001 for good vs. poor neurological outcome. S-100b was 0.127μg/l [0.063–0.360] vs. 0.772μg/l [0.121–2.710], p<0.001 and 0.086μg/l [0.061–0.122] vs. 0.138μg/l [0.090–0.271], p = 0.009, respectively. For mortality, thresholds of 36μg/l for NSE and 0.128μg/l for S-100b could be determined; for poor neurological outcome 33μg/l (NSE) and 0.123μg/l (S-100b), respectively. Positive predictive value for NSE was 81% (74–88) and 79% (71–85) for S-100b.

Conclusions

Thresholds for NSE and S-100b predicting mortality and poor neurological outcome are similar in OHCA patients receiving therapeutic hypothermia as in those reported before the era of hypothermia. However, both biomarkers do not have enough specificity to predict mortality or poor neurological outcome on their own and should only be additively used in clinical decision making.

In-hospital outcomes of mechanical complications in acute myocardial infarction: Analysis from a nationwide Spanish database

BACKGROUND

Mechanical complications represent an important cause of mortality in myocardial infarction (MI) patients. This is a nationwide study performed to evaluate possible changes in epidemiology or prognosis of these complications with current available strategies.

METHODS

Information was obtained from the minimum basis data set of the Spanish National Health System, including all hospitalizations for acute myocardial infarction (AMI) from 2010 to 2015. Risk-standardized in-hospital mortality ratio was calculated using multilevel risk adjustment models.

RESULTS

A total of 241,760 AMI episodes were analyzed, MI mechanical complications were observed in 842 patients: cardiac tamponade in 587, ventricular septal rupture in 126, and mitral regurgitation due to papillary muscle or chordae tendineae rupture in 155 (there was more than one complication in 21 patients). In-hospital mortality was 59.5%. On multivariate adjustment, variables with significant impact on in-hospital mortality were: age (OR 1.06; 95% CI 1.04-1.07; p < 0.001), ST-segment elevation AMI (OR 2.91; 95% CI 1.88-4.5; p < 0.001), cardiogenic shock (OR 2.35; 95% CI 1.66-3.32; p < 0.001), cardio-respiratory failure (OR 3.48; 95% CI 2.37-5.09; p < 0.001), and chronic obstructive pulmonary disease (OR 1.85; 95% CI 1.07-3.20; p < 0.001). No significant trends in risk-adjusted in-hospital mortality were detected (IRR 0.997; p = 0.109). Cardiac intensive care unit availability and more experience with mechanical complications management were associated with lower adjusted mortality rates (56.7 ± 5.8 vs. 60.1 ± 4.5; and 57 ± 6.1 vs. 59.9 ± 5.6, respectively; p < 0.001).

CONCLUSIONS

Mechanical complications occur in 3.5 per thousand AMI, with no significant trends to better survival over the past few years. Advanced age, cardiogenic shock and cardio-respiratory failure are the most important risk factors for in-hospital mortality. Higher experience and specialized cardiac intensive care units are associated with better outcomes.

Long-Term Clinical Outcome of Cardiogenic Shock Patients Undergoing Impella CP Treatment vs. Standard of Care

The number of patients treated with the mechanical circulatory support device Impella Cardiac Power (CP) for cardiogenic shock is steadily increasing. The aim of this study was to investigate long-term survival and complications related to this modality. Patients undergoing Impella CP treatment for cardiogenic shock were retrospectively enrolled and matched with cardiogenic shock patients not treated with mechanical circulatory support between 2010 and 2020. Data were collected from the cardiogenic shock registry of the university hospital of Munich (DRKS00015860). 70 patients with refractory cardiogenic shock without mechanical circulatory support were matched with 70 patients treated with Impella CP. At presentation, the mean age was 67 ± 15 years with 80% being male in the group without support and 67 ± 14 years (p = 0.97) with 76% being male (p = 0.68) in the group with Impella. There was no significant difference in the rate of cardiac arrest (47% vs. 51%, p = 0.73) and myocardial infarction was the predominant cause of cardiogenic shock in both groups (70% vs. 77%). A total of 41% of patients without cardiocirculatory support and 54% of patients with Impella support died during the first month (p = 0.17). After one year, mortality rates were similar in both groups (55% in conventional vs. 59% in Impella CP group, p = 0.30) as was mortality rate at long-term 5-years follow-up (64% in conventional vs. 73% in Impella CP group, p = 0.33). The rate of clinically significant bleedings during ICU stay was lower in the conventional group than in the Impella support group (15% vs. 43%, p = 0.002). In this small observational and non-randomized analysis no difference in long-term outcome between patients treated with Impella CP vs. guideline directed cardiogenic shock therapy without mechanical circulatory support could be detected. Care must be taken regarding the high rate of bleeding and vascular complications when using Impella CP. Large, adequately powered studies are urgently needed to investigate the efficacy and safety of Impella CP in cardiogenic shock.

Mechanical circulatory support in refractory cardiogenic shock due to influenza virus-related myocarditis

Background

There is scarce evidence for mechanical circulatory support (MCS) in patients with influenza-related myocarditis complicated by refractory cardiogenic shock (rCS). We sought to investigate the impact of MCS using combined veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and micro-axial flow pumps (the ECMELLA concept) in influenza-related myocarditis complicated by rCS.

Methods

This is a prospective, observational analysis from the single centre HAnnover Cardiac Unloading REgistry (HACURE) from two recent epidemic influenza seasons. We analysed patients with verified influenza-associated myocarditis complicated by rCS who were admitted to our intensive care unit (ICU) on MCS. Subsequently, we performed a propensity score (PS) matched analysis to patients with acute myocardial infarction (AMI) complicated by rCS and non-ischaemic cardiomyopathy (DCM) related rCS.

Results

We describe a series of seven patients with rCS-complicated influenza-related myocarditis (mean age 56±10 years, 58% male, influenza A (n=2)/influenza B (n=5)). No patient had been vaccinated prior to the influenza season. MCS was provided using combined VA-ECMO and Impella micro-axial flow pump. In two patients with out-of-hospital cardiac arrest, VA-ECMO had been implanted for extracorporeal cardiopulmonary resuscitation. All patients died within 18 days of hospital admission. By PS-based comparison to patients with AMI- or DCM-related rCS and combined MCS, 30-day mortality was significantly higher in influenza-related rCS.

Conclusion

Despite initial stabilisation with combined MCS in patients with rCS-complicated influenza-related myocarditis, the detrimental course of shock could not be stopped and all patients died. Influenza virus infection potentially critically affects other organs besides the heart, leading to irreversible end-organ damage that MCS cannot compensate for and, therefore, results in a devastating outcome.

Combined mechanical circulatory support in refractory cardiogenic shock (ECMELLA) might not salvage patients with influenza-associated myocarditis and severe end-organ damage, in contrast to the favourable effects in primary cardiac causeshttps://bit.ly/3dmonC4

Influence of Timing and Predicted Risk on Mortality in Impella-Treated Infarct-Related Cardiogenic Shock Patients

Background: In-hospital mortality in acute myocardial infarction-related cardiogenic shock (AMI-CS) remains high. The only adequately powered randomized trial showed no benefit of routine use of the intra-aortic balloon pump in AMI-CS. We compared individually predicted mortality using CardShock- and IABP-Shock II-scores in AMI-CS patients treated with an Impella microaxial pump, who met the IABP-Shock II-trials inclusion/exclusion criteria, to observed mortality on circulatory support in order to determine whether standardized use of an Impella microaxial flow-pump in AMI-CS is associated with lower than predicted mortality rates and whether timing of implantation or selecting patients based on predicted risk is meaningful.

Methods and Results: We analyzed data from 166 consecutive Impella-treated AMI-CS patients meeting the inclusion/exclusion criteria of the IABP-Shock II-trial (age 64 ± 11 years). Thirty-nine percentage of 64 patients had been resuscitated before Impella implantation. Overall 30-day mortality was 42%. Mortality was higher in resuscitated patients (50 vs. 36%, p = 0.0452) and when Impella was implanted post-PCI (Impella-pre-PCI: 28%, Impella-post-PCI: 51%, p = 0.0039). While in both score systems there was no significant difference between predicted and observed overall 30-day mortality, predicted mortality was significantly higher than observed mortality on Impella support only for individuals with highest predicted risk based on CardShock score (predicted 77 vs. observed 51%, p = 0.025).

Conclusions: Our retrospective analysis suggests that the use of the Impella microaxial pump may be effective in selected cases of high risk patients with AMI-CS.

Condensed abstract: Mortality is high in acute myocardial infarction-related cardiogenic shock despite rapid revascularization. Haemodynamic support with an intraortic balloon pump does not reduce mortality. In this retrospective registry including 166 consecutive IABP-Shock II-eligible cardiogenic shock patients in four dedicated shock centers, observed mortality on circulatory support with an Impella was significantly lower than predicted in patients with highest mortality risk. Implantation prior to PCI in acute myocardial infarction-related cardiogenic shock seemed to be associated with lower mortality than implantation post PCI.

Impella RP support in refractory right ventricular failure complicating acute myocardial infarction with unsuccessful right coronary artery revascularization

BACKGROUND

Impella RP has been used to treat right ventricular failure (RVF) developing in various clinical settings that underlay different pathological mechanisms and lead to distinct prognostic implications.

METHODS

This is a single-centre retrospective study including all consecutive patients, from January 2015 to December 2018, with inferior STEMI due to acute thrombotic occlusion of right coronary artery (RCA) and unsuccessful primary percutaneous coronary intervention (PCI) complicated by refractory RVF managed with an Impella RP device.

RESULTS

A total of 5 patients have been treated. The mean age was 73 ± 9 years, 80% were males. All patients, except one, were hemodynamically stable at hospital admission. In all patients, PCI resulted unsuccessful (final TIMI flow < 3), with subsequent development of refractory RVF and cardiogenic shock in the catheterization laboratory, despite the use of inotropes and intra-aortic balloon pump (IABP). In 80% of the cases, Impella RP was placed immediately after PCI. Hemodynamics improved immediately after initiation of Impella RP support, with an increase in systolic blood pressure from 91 ± 17 to 136 ± 13 mmHg, a decrease in central venous pressure from 16 ± 2.5 to 12 ± 4 mmHg and a resolution in lactates from 4.5 ± 2.5 to 1.6 ± 0.7 mg/dL. Mean duration of IABP and Impella RP support were 4 and 7 days, respectively. RV recovery occurred in 80% of the cases. All patients survived at 30-day.

CONCLUSIONS

In patients with AMI complicated by unsuccessful revascularization of RCA and refractory RVF, the use of Impella RP device resulted in immediate hemodynamic benefit with reversal of shock and favourable survival at 30-day.