Extracorporeal Life Support in Cardiogenic Shock Complicating Acute Myocardial Infarction

Effects and safety of extracorporeal membrane oxygenation in the treatment of patients with ST-segment elevation myocardial infarction and cardiogenic shock: A systematic review and meta-analysis

Background

There is a lack of large randomized controlled trials (RCTs) that comprehensively evaluate the effects of venoarterial extracorporeal membrane oxygenation (V-A ECMO)- assisted treatment of patients with ST-segment elevation myocardial infarction (STEMI) combined with Cardiogenic shock (CS). This meta-analysis aims to identify predictors of short-term mortality, and the incidence of various complications in patients with STEMI and CS treated with V-A ECMO.

Methods

We searched PubMed, Cochrane Library, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and the Wanfang Database from 2008 to January 2022 for studies evaluating patients with STEMI and CS treated with V-A ECMO. Studies that reported on mortality in ≥ 10 adult (>18 years) patients were included. Newcastle-Ottawa Scale was used by two independent reviewers to assess methodological quality. Mantel-Haenszel models were used to pool the data for meta-analysis.

Results

Sixteen studies (1,162 patients) were included with a pooled mortality estimate of 50.9%. Age > 65 years, BMI > 25 kg/m², lactate > 8 mmol/L, anterior wall infarction, longer CPR time, and longer time from arrest to extracorporeal cardiopulmonary resuscitation (ECPR) were risk predictors of mortality. Achieving TIMI-3 flow after percutaneous coronary intervention (PCI) was a protective factor of mortality. The prevalence of bleeding, cerebral infarction, leg ischemia, and renal failure were 22, 9.9, 7.4, and 49.4%, respectively.

Conclusion

Our study identified Age, BMI, lactate, anterior wall infarction, TIMI-3 flow after PCI, CPR time, and time from arrest to ECPR significantly influence mortality in STEMI patients with CS requiring V-A ECMO. These factors may help clinicians to detect patients with poor prognoses earlier and develop new mortality prediction models.

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.

Incidence and Outcome of Patients with Cardiogenic Shock and Detection of Herpes Simplex Virus in the Lower Respiratory Tract

(1) Herpes simplex virus (HSV) reactivation in critically ill patients can cause infection in the lower respiratory tract, prolonging mechanical ventilation. However, the association of HSV reactivation with cardiogenic shock (CS) is unclear. As CS is often accompanied by pulmonary congestion and reduced immune system activity, the aim of our study was to determine the incidence and outcome of HSV reactivation in these patients. (2) In this retrospective, single-center study, bronchial lavage (BL) was performed on 181 out of 837 CS patients with mechanical ventilation. (3) In 44 of those patients, HSV was detected with a median time interval of 11 days since intubation. The occurrence of HSV was associated with an increase in C-reactive protein and the fraction of inspired oxygen at the time of HSV detection. Arterial hypertension, bilirubin on ICU admission, the duration of mechanical ventilation and out-of-hospital cardiac arrest were associated with HSV reactivation. (4) HSV reactivation could be detected in 24.3% of patients with CS on whom BL was performed, and its occurrence should be considered in patients with prolonged mechanical ventilation. Due to the limited current evidence, the initiation of treatment for these patients remains an individual choice. Dedicated randomized studies are necessary to investigate the efficacy of antiviral therapy.

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]).

The Use of Mechanical Circulatory Assist Devices for ACS Patients with Cardiogenic Shock and High-Risk PCI

PURPOSE OF REVIEW

There has been a significant expansion of the use of mechanical circulatory support (MCS) devices for patient with acute coronary syndromes (ACS) with cardiogenic shock (CS) and in patients undergoing high-risk percutaneous interventions (PCI). The purpose of this review is to provide an overview of the indications and outcomes of these devices in high-risk cardiac patients.

RECENT FINDINGS

Early revascularization of the culprit-lesion is the immediate goal in ACS patients with CS and the use of pulmonary artery catheters has been associated with improved outcomes in patients with cardiogenic shock. The MCS devices that are used for myocardial support include the intra-aortic balloon pump (IABP), the left ventricle (LV) to aorta pumps, left atrium (LA) to arterial pumps, and right atrial (RA) to arterial pumps. This review provides an overview on the use of these devices in patients with ACS and CS and those undergoing high-risk PCI. Attention is focused on the IABP, the Impella (LV-aorta pump), the TandemHeart (LA-arterial pump), and veno-arterial extracorporeal membrane oxygenation (RA-arterial pump). The indications, evidence, and complications of each device are reviewed. Each device varies in its physiological effect on native heart function, complexity in insertion, and complications. The use of MCS devices for high-risk PCI and CS has increased in recent years and have demonstrated efficacy in supporting a vulnerable myocardium. Although recommendations can be made for use of each device in certain clinical scenarios, further evidence through registries and clinical trials is necessary to guide appropriate device utilization.

PCI in Patients With Heart Failure: Current Evidence, Impact of Complete Revascularization, and Contemporary Techniques to Improve Outcomes

Coronary artery disease (CAD) is the most common cause of left ventricular systolic dysfunction (LVSD) and heart failure (HF). Revascularization with coronary artery bypass grafting (CABG) reduces all-cause mortality compared with medical therapy alone for these patients. Despite this, CABG is performed in a minority of patients with HF, partly due to patient unwillingness or inability to undergo major cardiac surgery and partly due to physician reluctance to refer for surgery due to high operative risk. Percutaneous coronary intervention (PCI) is a less-invasive method of revascularization that has the potential to reduce periprocedural complications compared with CABG in patients with HF. Recent advances in PCI technology and technique have made it realistic to achieve more complete revascularization with PCI in high-risk patients with HF, although no randomized controlled clinical trials (RCTs) of PCI in HF compared with either medical therapy or CABG have been performed. In this review, we discuss the currently available evidence for PCI in HF and the association between the extent of revascularization and clinical outcomes in HF. We also review recent advances in PCI technology and techniques with the potential to improve clinical outcomes in HF. Finally, we discuss emerging clinical trial evidence of revascularization in HF and the large, persistent evidence gaps that should be addressed with future clinical trials of revascularization in HF.

Mechanical circulatory support in cardiogenic shock and post-myocardial infarction mechanical complications

Despite advanced therapies, the mortality of patients with myocardial infarction (MI) complicated by cardiogenic shock (CS) remains around 50%. Mechanical complications of MI are rare nowadays but associated with high mortality in patients who present with CS. Different treatment strategies and mechanical circulatory support (MCS) devices have been increasingly used to improve the grim prognosis of refractory CS. This article discusses current evidence regarding the use of MCS in MI complicated by CS, ventricular septal rupture, free wall rupture and acute mitral regurgitation. Device selection should be tailored according to the cause and severity of CS. Early MCS initiation and multidisciplinary team cooperation is mandatory for good results. MCS associated bleeding remains a major complication and an obstacle to better outcomes. Ongoing prospective randomized trials will improve current knowledge regarding MCS indications, timing, and patient selection in the coming years.

Extracorporeal Membrane Oxygenation in Infarct-Related Cardiogenic Shock

Mortality in infarct-related cardiogenic shock (CS) remains high, reaching 40-50%. In refractory CS, active mechanical circulatory support devices including veno-arterial extracorporeal membrane oxygenation (VA-ECMO) are rapidly evolving. However, supporting evidence of VA-ECMO therapy in infarct-related CS is low. The current review aims to give an overview on the basics of VA-ECMO therapy, current evidence, ongoing trials, patient selection and potential complications.

Comparative Analysis of Patient Characteristics in Cardiogenic Shock Studies: Differences Between Trials and Registries

OBJECTIVES

This study sought to evaluate the differences in cardiogenic shock patient characteristics in trial patients and real-life patients.

BACKGROUND

Cardiogenic shock (CS) is a leading cause of mortality in patients presenting with acute myocardial infarction (AMI). However, the enrollment of patients into clinical trials is challenging and may not be representative of real-world patients.

METHODS

We performed a systematic review of studies in patients presenting with AMI-related CS and compared patient characteristics of those enrolled into randomized controlled trials (RCTs) with those in registries.

RESULTS

We included 14 RCTs (n = 2,154) and 12 registries (n = 133,617). RCTs included more men (73% vs 67.7%, P < 0.001) compared with registries. Patients enrolled in RCTs had fewer comorbidities, including less hypertension (61.6% vs 65.9%, P < 0.001), dyslipidemia (36.4% vs 53.6%, P < 0.001), a history of stroke or transient ischemic attack (7.1% vs 10.7%, P < 0.001), and prior coronary artery bypass graft surgery (5.4% vs 7.5%, P < 0.001). Patients enrolled in RCTs also had lower lactate levels (4.7 ± 2.3 mmol/L vs 5.9 ± 1.9 mmol/L, P < 0.001) and higher mean arterial pressure (73.0 ± 8.8 mm Hg vs 62.5 ± 12.2 mm Hg, P < 0.001). Percutaneous coronary intervention (97.5% vs 58.4%, P < 0.001) and extracorporeal membrane oxygenation (11.6% vs 3.4%, P < 0.001) were used more often in RCTs. The in-hospital mortality (23.9% vs 38.4%, P < 0.001) and 30-day mortality (39.9% vs 45.9%, P < 0.001) were lower in RCT patients.

CONCLUSIONS

RCTs in AMI-related CS tend to enroll fewer women and lower-risk patients compared with registries. Patients enrolled in RCTs are more likely to receive aggressive treatment with percutaneous coronary intervention and extracorporeal membrane oxygenation and have lower in-hospital and 30-day mortality.

Mortality in cardiogenic shock patients receiving mechanical circulatory support: a network meta-analysis

Objective

Mechanical circulatory support (MCS) devices are widely used for cardiogenic shock (CS). This network meta-analysis aims to evaluate which MCS strategy offers advantages.

Methods

A systemic search of PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials was performed. Studies included double-blind, randomized controlled, and observational trials, with 30-day follow-ups. Paired independent researchers conducted the screening, data extraction, quality assessment, and consistency and heterogeneity assessment.

Results

We included 39 studies (1 report). No significant difference in 30-day mortality was noted between venoarterial extracorporeal membrane oxygenation (VA-ECMO) and VA-ECMO plus Impella, Impella, and medical therapy. According to the surface under the cumulative ranking curve, the optimal ranking of the interventions was surgical venting plus VA-ECMO, medical therapy, VA-ECMO plus Impella, intra-aortic balloon pump (IABP), Impella, Tandem Heart, VA-ECMO, and Impella plus IABP. Regarding in-hospital mortality and 30-day mortality, the forest plot showed low heterogeneity. The results of the node-splitting approach showed that direct and indirect comparisons had a relatively high consistency.

Conclusions

IABP more effectively reduce the incidence of 30-day mortality compared with VA-ECMO and Impella for the treatment of CS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02493-0.

Cardiogenic Shock Management and Research: Past, Present, and Future Outlook

Although great strides have been made in the pathophysiological understanding, diagnosis and management of cardiogenic shock (CS), morbidity and mortality in patients presenting with the condition remain high. Acute MI is the commonest cause of CS; consequently, most existing literature concerns MI-associated CS. However, there are many more phenotypes of patients with acute heart failure. Medical treatment and mechanical circulatory support are well-established therapeutic options, but evidence for many current treatment regimens is limited. The issue is further complicated by the fact that implementing adequately powered, randomized controlled trials are challenging for many reasons. In this review, the authors discuss the history, landmark trials, current topics of medical therapy and mechanical circulatory support regimens, and future perspectives of CS management.

Cardiac Surgery in Advanced Heart Failure

Mechanical circulatory support and heart transplantation are established surgical options for treatment of advanced heart failure. Since the prevalence of advanced heart failure is progressively increasing, there is a clear need to treat more patients with mechanical circulatory support and to increase the number of heart transplantations. This narrative review summarizes recent progress in surgical treatment options of advanced heart failure and proposes an algorithm for treatment of the advanced heart failure patient at >65 years of age.

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.

Comparison of ECMO vs ECpella in patients with non post-pericardiotomy cardiogenic shock: An updated meta-analysis

INTRODUCTION

The impact of Impella and ECMO (ECPELLA) in cardiogenic shock (CS) remains to be defined. The aim of this meta-analysis is to evaluate the benefit of ECPELLA compared to VA-ECMO in patients with non post-pericardiotomy CS.

METHODS

All studies reporting short term outcomes of ECpella or VA ECMO in non post-pericardiotomy CS were included. The primary endpoint was 30-day mortality. Vascular and bleeding complications and LVAD implantation/heart transplant within 30-days were assessed as secondary outcomes.

RESULTS

Of 407 studies identified, 13 observational studies (13,682 patients, 13,270 with ECMO and 412 with ECpella) were included in this analysis. 30-day mortality was 55.8% (51.6-59.9) in the VA-ECMO group and 58.3% (53.5-63.0) in the ECpella group. At meta-regression analysis the implantation of IABP did not affect mortality in the ECMO group. The rate of major bleeding in patients on VA-ECMO and ECpella support were 21.3% (16.9-26.5) and 33.1% (25.9-41.2) respectively, while the rates of the composite outcome of LVAD implantation and heart transplantation within 30-days in patients on VA-ECMO and ECpella support were 14.4% (9.0-22.2) and 10.8%. When directly compared in 3 studies, ECpella showed a positive effect on 30-day mortality compared to ECMO (OR: 1.81: 1.039-3.159).

CONCLUSION

Our data suggest that ECpella may reduce 30-day mortality and increase left ventricle recovery, despite increased of bleeding rates.

Complications After Heart Transplantation According to the Type of Pretransplant Circulatory/Ventricular Support

BACKGROUND

The purpose of the study was to analyze postcardiac transplant complications in patients who received transplants with short-term mechanical ventricular assist devices and to compare complications according to the type of device.

METHODS

Ambispective and consecutive study of urgent heart transplants from 2015 to 2019. Pediatric transplants, retransplants, and combined transplants were excluded. A total of 45 patients were analyzed in 4 groups: (1) venoarterial extracorporeal membrane oxygenation (ECMO) implanted <10 days before heart transplant (HTx) (n = 17); (2) ECMO implanted for more than 10 days (n = 8); (3) Levitronix Centrimag implanted in INTERMACS 2 to 3 patients (n = 13); and (4) Levitronix Centrimag implanted in INTERMACS 2 patients (n = 7). ECMO assistance was in INTERMACS 2 and severe right ventricular dysfunction. Levitronix Centrimag was implanted in patients with preserved right ventricular function.

RESULTS

Primary graft failure associated with the need for ECMO was more frequent in patients with ECMO than with Levitronix (P < .05). When comparing the 2 groups with ECMO, an implant more than 10 days before HTx was associated, after transplant, with a longer stay in the critical care unit (P = .02), higher mortality (P = .03), and an increase in complications in general. When comparing the 2 groups with Levitronix, all the parameters studied were much better when the Levitronix was implanted in INTERMACS 2-3 (P < .05). On the other hand, all cases of deep vein thrombosis and pulmonary thromboembolism occurred in patients who were assisted with ECMO.

CONCLUSIONS

HTx with mechanical assist devices is associated with significant complications. ECMO produces more complications than the Levitronix Centrimag, although they are related to the days of implantation. The best group are patients implanted with a Levitronix in INTERMACS 2-3.

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.

Temporary mechanical circulatory support devices: updates from recent studies

PURPOSE OF REVIEW

Over the past several years, the role of short-term mechanical circulatory support (MCS) devices has become the dominant focus in efforts to improve outcomes in patients with cardiogenic shock (CS). Alongside these efforts, temporary MCS devices have been increasingly used to support patients prior to cardiac surgery, during high-risk percutaneous coronary intervention, awaiting cardiac transplantation, and in the setting of refractory cardiac arrest. The present review aims to provide an update on the recent literature evaluating the evolving role of temporary MCS devices, and to provide insights into the current challenges and future directions of MCS research.

RECENT FINDINGS

Recent observational data have demonstrated potential roles for intra-aortic balloon pump preoperatively in high-risk patients awaiting coronary artery bypass grafting, and advanced heart failure patients awaiting transplantation. Impella continues to demonstrate promising results as part of an early MCS strategy in CS, as a temporary bridge to transplantation, and as a mechanism for left ventricular unloading in patients on venoarterial extracorporeal membrane oxygenation (ECMO). Finally, the first randomized trial of ECMO facilitated resuscitation in the United States demonstrated improved survival in patients with refractory out of hospital cardiac arrest.

SUMMARY

Though randomized data remains limited, observational data continue to support the role of temporary MCS devices in a variety of clinical settings.

The mechanical support of cardiogenic shock

PURPOSE OF REVIEW

Cardiogenic shock (CS) therapy involving catecholamines, inotropes, fluids and revascularization is often insufficient, and short-term mortality remains 50%. Different treatment algorithms and mechanical circulatory support devices (MCS) have been increasingly used in the treatment of CS. Coronavirus disease 2019 (COVID-19) pandemic is a major challenge faced by intensive care medicine providers inevitably influencing also CS management.

RECENT FINDINGS

There is a lack of prospective data as well as international consensus regarding CS classification, patient risk stratification, and MCS use. Veno-arterial extracorporeal membrane oxygenation is considered the first line MCS in refractory CS and Impella the MCS of choice for the left ventricle unloading. Several ongoing randomized trials will provide much-needed evidence for MCS use in the coming years. COVID-19 infection is associated with several cardiovascular disorders complicated by CS and more data regarding the prevalence and mortality of CS during COVID-19 infection are needed.

SUMMARY

This review summarizes current trends in the use of MCS in CS and discusses differences in CS management during the COVID-19 pandemic. Careful patient selection, early MCS initiation, and comprehensive intensive care by experienced team is key to successful outcome in patients with refractory CS.

Predictors of Mortality in Patients Treated with Veno-Arterial ECMO for Cardiogenic Shock Complicating Acute Myocardial Infarction: a Systematic Review and Meta-Analysis

BACKGROUND

Mortality for patients on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for cardiogenic shock (CS) complicating acute myocardial infarction (AMI) remains high. This meta-analysis aims to identify factors that predict higher risk of mortality after VA-ECMO for AMI.

METHODS

We meta-analyzed mortality after VA-ECMO for CS complicating AMI and the effect of factors from systematically selected studies published after 2009.

RESULTS

72 studies (10,276 patients) were included with a pooled mortality estimate of 58 %. With high confidence in estimates, failure to achieve TIMI III flow and left main culprit were identified as factors associated with higher mortality. With low-moderate confidence, older age, high BMI, renal dysfunction, increasing lactate, prothrombin activity < 50%, VA-ECMO implantation after revascularization, and non-shockable ventricular arrythmias were identified as factors associated with mortality.

CONCLUSION

These results provide clinicians with a framework for selecting patients for VA-ECMO for CS complicating AMI.

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.

Association Between Timing of Extracorporeal Membrane Oxygenation and Clinical Outcomes in Refractory Cardiogenic Shock

OBJECTIVES

The aim of this study was to investigate whether earlier extracorporeal membrane oxygenation (ECMO) support is associated with improved clinical outcomes in patients with refractory cardiogenic shock (CS).

BACKGROUND

The prognosis of patients with refractory CS receiving ECMO remains poor. However, little is known about the association between the timing of ECMO implantation and clinical outcomes in these patients.

METHODS

From a multicenter registry, 362 patients with refractory CS who underwent ECMO between January 2014 and December 2018 were identified. Participants were classified into 3 groups according to tertiles of shock-to-ECMO time (early, intermediate, and late ECMO). Inverse probability of treatment weighting was conducted to adjust for baseline differences among the groups, followed by a weighted Cox proportional hazards regression analysis to calculate hazard ratios and 95% confidence intervals for 30-day mortality associated with each ECMO time group.

RESULTS

The overall 30-day mortality rate was 40.9%. The risk for 30-day mortality was lower in the early group than in the late group (hazard ratio: 0.53; 95% confidence interval: 0.28 to 0.99). Early ECMO support was also associated with lower risk for in-hospital mortality, ECMO weaning failure, composite of all-cause mortality or rehospitalization for heart failure at 1 year, all-cause mortality at 1 year, and poor neurological outcome at discharge. However, the incidence of adverse events, including stroke, limb ischemia, ECMO-site bleeding, and gastrointestinal bleeding, did not differ significantly among the groups.

CONCLUSIONS

Earlier ECMO support was associated with improved clinical outcomes in patients with refractory CS.

Variability in reporting of key outcome predictors in acute myocardial infarction cardiogenic shock trials

BACKGROUND

Among acute myocardial infarction patients with cardiogenic shock (AMICS), a number of key variables predict mortality, including cardiac arrest (CA) and shock classification as proposed by Society for Cardiovascular Angiography and Intervention (SCAI). Given this prognostic importance, we examined the frequency of reporting of high risk variables in published randomized controlled trials (RCTs) of AMICS patients.

METHODS

We identified 15 RCTs enrolling 2,500 AMICS patients and then reviewed rates of CA, baseline neurologic status, right heart catheterization data, lactate levels, inotrope and vasopressor requirement, hypothermia, mechanical ventilation, left ventricular ejection fraction (LVEF), mechanical circulatory support, and specific cause of death based on the primary manuscript and Data in S1.

RESULTS

A total of 2,500 AMICS patients have been enrolled in 15 clinical trials over 21 years with only four trials enrolling >80 patients. The reporting frequency and range for key prognostic factors was: neurologic status (0% reported), hypothermia (28% reported, prevalence 33-75%), specific cause of death (33% reported), cardiac index and wedge pressure (47% reported, range 1.6-2.3 L min^-1 m^-2 and 15-24 mmHg), lactate (60% reported, range 4-7.7 mmol/L), LVEF (73% reported, range 25-45%), CA (80% reported, prevalence 0-92%), MCS (80% reported, prevalence 13-100%), and mechanical ventilation (93% reported, prevalence 35-100%). This variability was reflected in the 30-day mortality which ranged from 20-73%.

CONCLUSIONS

In a comprehensive review of seminal RCTs in AMICS, important predictors of outcome were frequently not reported. Future efforts to standardize CS trial data collection and reporting may allow for better assessment of novel therapies for AMICS.

Extracorporeal life support in patients with acute myocardial infarction complicated by cardiogenic shock - Design and rationale of the ECLS-SHOCK trial

BACKGROUND

In acute myocardial infarction complicated by cardiogenic shock the use of mechanical circulatory support devices remains controversial and data from randomized clinical trials are very limited. Extracorporeal life support (ECLS) - venoarterial extracorporeal membrane oxygenation - provides the strongest hemodynamic support in addition to oxygenation. However, despite increasing use it has not yet been properly investigated in randomized trials. Therefore, a prospective randomized adequately powered clinical trial is warranted.

STUDY DESIGN

The ECLS-SHOCK trial is a 420-patient controlled, international, multicenter, randomized, open-label trial. It is designed to compare whether treatment with ECLS in addition to early revascularization with percutaneous coronary intervention or alternatively coronary artery bypass grafting and optimal medical treatment is beneficial in comparison to no-ECLS in patients with severe infarct-related cardiogenic shock. Patients will be randomized in a 1:1 fashion to one of the two treatment arms. The primary efficacy endpoint of ECLS-SHOCK is 30-day mortality. Secondary outcome measures such as hemodynamic, laboratory, and clinical parameters will serve as surrogate endpoints for prognosis. Furthermore, a longer follow-up at 6 and 12 months will be performed including quality of life assessment. Safety endpoints include peripheral ischemic vascular complications, bleeding and stroke.

CONCLUSIONS

The ECLS-SHOCK trial will address essential questions of efficacy and safety of ECLS in addition to early revascularization in acute myocardial infarction complicated by cardiogenic shock.

Sex differences in patients with cardiogenic shock

Aims

Differences between female and male patients in clinical presentation, causes and treatment of cardiogenic shock (CS) are poorly understood. We aimed to investigate sex differences in presentation with and treatment of CS.

Methods and results

We analysed data of 978 patients presenting with CS to a tertiary care hospital between October 2009 and October 2017. Multivariable adjusted logistic/Cox regression models were fitted to investigate the association between sex and clinical presentation, use of treatments and 30 day mortality.

Median age was 70 years (interquartile range 58–79 years), and 295 (30.2%) patients were female. After adjustment for multiple relevant confounders, female patients were more likely to be older [odds ratio (OR) 1.21, 95% confidence interval (CI) 1.02–1.42, P = 0.027], but other relevant presentation characteristics did not differ between both sexes. Despite the similar presentation, female patients were less likely to be treated with percutaneous left ventricular assist devices (OR 0.78, 95% CI 0.64–0.94, P = 0.010), but more likely to be treated with catecholamines (OR 1.21, 95% CI 1.02–1.44, P = 0.033) or vasopressors (OR 1.26, 95% CI 1.05–1.50, P = 0.012). A 30 day mortality risk in female patients was as high as in male patients (hazard ratio 1.08, 95% CI 1.00–1.18, P = 0.091).

Conclusions

In this large, contemporary cohort, clinical presentation was comparable in female and male patients, and both sexes were associated with a comparably high mortality risk. Nevertheless, female patients received different treatment for CS and were most importantly less likely to be treated with percutaneous left ventricular assist devices.

Contemporary device management of cardiogenic shock following acute myocardial infarction

Despite advances in the overall management of acute myocardial infarction (AMI), cardiogenic shock in the setting of AMI (CS-AMI) continues to be associated with poor patient outcomes. There are multiple devices that can be used in CS-AMI to support the failing circulation, although their utility in improving outcomes as compared with conventional pharmacotherapy of vasopressors and inotropes remains to be established. This contemporary review provides an update on the evidence base for each of these techniques. In CS-AMI, acute thrombotic occlusion of a major epicardial artery leads to hypoxia and myocardial ischaemia in the territory subtended by that vessel. The resultant regional dysfunction in myocardial contractility can severely compromise stroke volume and result in acute circulatory failure, systemic hypoperfusion, lactic acidosis, multi-organ failure and ultimately death.

Risk Scores in ST-Segment Elevation Myocardial Infarction Patients with Refractory Cardiogenic Shock and Veno-Arterial Extracorporeal Membrane Oxygenation

Although many risk models have been tested in patients implanted by veno-arterial extracorporeal membrane oxygenation (VA-ECMO), few scores assessed patients’ prognosis in the setting of ST-segment elevation myocardial infarction (STEMI) with refractory cardiogenic shock. We aimed at assessing the performance of risk scores, notably the prEdictioN of Cardiogenic shock OUtcome foR AMI patients salvaGed by VA-ECMO (ENCOURAGE) score, for predicting mortality in this particular population. This retrospective observational study included patients admitted to Tours University Hospital for STEMI with cardiogenic shock and requiring hemodynamic support by VA-ECMO. Among the fifty-one patients, the 30-day and 6-month survival rates were 63% and 56% respectively. Thirty days after VA-ECMO therapy, probabilities of mortality were 12, 17, 33, 66, 80% according to the ENCOURAGE score classes 0–12, 13–18, 19–22, 23–27, and ≥28, respectively. The ENCOURAGE score (AUC of the Receiving Operating Characteristic curve = 0.83) was significantly better compared to other risk scores. The hazard ratio for survival at 30 days for each point of the ENCOURAGE score was 1.10 (CI 95% (1.06, 1.15); p < 0.001). Decision curve analysis indicated that the ENCOURAGE score had the best clinical usefulness of the tested risk scores and the Hosmer–Lemeshow test suggested an accurate calibration. Our data suggest that the ENCOURAGE score is valid and the most relevant score to predict 30-day mortality after VA-ECMO therapy in STEMI patients with refractory cardiogenic shock. It may help decision-making teams to better select STEMI patients with shock for VA-ECMO therapy.

Biventricular Unloading with Impella and Venoarterial Extracorporeal Membrane Oxygenation in Severe Refractory Cardiogenic Shock: Implications from the Combined Use of the Devices and Prognostic Risk Factors of Survival

Since mechanical circulatory support (MCS) devices have become integral component in the therapy of refractory cardiogenic shock (RCS), we identified 67 patients in biventricular support with Impella and venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO) for RCS between February 2013 and December 2019 and evaluated the risk factors of mortality in this setting. Mean age was 61.07 ± 10.7 and 54 (80.6%) patients were male. Main cause of RCS was acute myocardial infarction (AMI) (74.6%), while 44 (65.7%) were resuscitated prior to admission. The mean Simplified Acute Physiology Score II (SAPS II) and Sequential Organ Failure Assessment Score (SOFA) score on admission was 73.54 ± 16.03 and 12.25 ± 2.71, respectively, corresponding to an expected mortality of higher than 80%. Vasopressor doses and lactate levels were significantly decreased within 72 h on biventricular support (p < 0.05 for both). Overall, 17 (25.4%) patients were discharged to cardiac rehabilitation and 5 patients (7.5%) were bridged successfully to ventricular assist device implantation, leading to a total of 32.8% survival on hospital discharge. The 6-month survival was 31.3%. Lactate > 6 mmol/L, vasoactive score > 100 and pH < 7.26 on initiation of biventricular support, as well as Charlson comorbity index > 3 and prior resuscitation were independent predictors of survival. In conclusion, biventricular support with Impella and VA-ECMO in patients with RCS is feasible and efficient leading to a better survival than predicted through traditional risk scores, mainly via significant hemodynamic improvement and reduction in lactate levels.

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.

Left Ventricular Unloading Is Associated With Lower Mortality in Patients With Cardiogenic Shock Treated With Venoarterial Extracorporeal Membrane Oxygenation: Results From an International, Multicenter Cohort Study

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used to treat cardiogenic shock. However, VA-ECMO might hamper myocardial recovery. The Impella unloads the left ventricle. This study aimed to evaluate whether left ventricular unloading in patients with cardiogenic shock treated with VA-ECMO was associated with lower mortality.

METHODS

Data from 686 consecutive patients with cardiogenic shock treated with VA-ECMO with or without left ventricular unloading using an Impella at 16 tertiary care centers in 4 countries were collected. The association between left ventricular unloading and 30-day mortality was assessed by Cox regression models in a 1:1 propensity score-matched cohort.

RESULTS

Left ventricular unloading was used in 337 of the 686 patients (49%). After matching, 255 patients with left ventricular unloading were compared with 255 patients without left ventricular unloading. In the matched cohort, left ventricular unloading was associated with lower 30-day mortality (hazard ratio, 0.79 [95% CI, 0.63-0.98]; P=0.03) without differences in various subgroups. Complications occurred more frequently in patients with left ventricular unloading: severe bleeding in 98 (38.4%) versus 45 (17.9%), access site-related ischemia in 55 (21.6%) versus 31 (12.3%), abdominal compartment in 23 (9.4%) versus 9 (3.7%), and renal replacement therapy in 148 (58.5%) versus 99 (39.1%).

CONCLUSIONS

In this international, multicenter cohort study, left ventricular unloading was associated with lower mortality in patients with cardiogenic shock treated with VA-ECMO, despite higher complication rates. These findings support use of left ventricular unloading in patients with cardiogenic shock treated with VA-ECMO and call for further validation, ideally in a randomized, controlled trial.

Clinical Implications of Thrombocytopenia at Cardiogenic Shock Presentation: Data from a Multicenter Registry

PURPOSE

Thrombocytopenia (platelet count <150×10³/μL) is associated with poor outcomes in various critical illness settings. However, the prognostic value of platelet count in patients with cardiogenic shock (CS) remains unclear.

MATERIALS AND METHODS

We enrolled 1202 patients between January 2014 and December 2018 from a multicenter retrospective-prospective cohort registry of CS. Clinical characteristics and treatment outcomes were compared between the patients with and without thrombocytopenia.

RESULTS

At presentation with CS, 244 (20.3%) patients had thrombocytopenia. The patients with thrombocytopenia had lower blood pressure, hemoglobin level, and worse liver and renal functions compared to the patients without. During hospitalization, the patients with thrombocytopenia had more frequent gastrointestinal bleeding (10.5% vs. 3.8%, p=0.009), sepsis (8.3% vs. 2.6%, p=0.013), requirement of renal replacement therapy (36.5% vs. 18.9%, p<0.001), requirement of mechanical ventilation (65.2% vs. 54.4%, p=0.003), longer intensive care unit stay (8 days vs. 4 days, p<0.001), and thirty-day mortality (40.2% vs. 28.5%, p<0.001) compared to those without. In addition, the platelet count was an independent predictor of 30-day mortality (per 10³/μL decrease; adjusted hazard ratio: 1.002, 95% confidence interval: 1.000-1.003, p=0.021).

CONCLUSION

Thrombocytopenia at CS presentation was associated with worse clinical findings, higher frequencies of complications, and longer stay at the intensive care unit. Also, thrombocytopenia was independently associated with increased 30-day mortality. (Clinical trial registration No. NCT02985008).

The science of safety: complications associated with the use of mechanical circulatory support in cardiogenic shock and best practices to maximize safety

Acute mechanical circulatory support (MCS) devices are widely used in cardiogenic shock (CS) despite a lack of high-quality clinical evidence to guide their use. Multiple devices exist across a spectrum from modest to complete support, and each is associated with unique risks. In this review, we summarize existing data on complications associated with the three most widely used acute MCS platforms: the intra-aortic balloon pump (IABP), Impella systems, and veno-arterial extracorporeal membrane oxygenation (VA-ECMO). We review evidence from available randomized trials and highlight challenges comparing complication rates from case series and comparative observational studies where a lack of granular data precludes appropriate matching of patients by CS severity. We further offer a series of best practices to help shock practitioners minimize the risk of MCS-associated complications and ensure the best possible outcomes for patients.

Temporary circulatory support for cardiogenic shock

Cardiogenic shock can occur due to acute ischaemic or non-ischaemic cardiac events, or from progression of long-standing underlying heart disease. When addressing the cause of underlying disease, the management of cardiogenic shock consists of vasopressors and inotropes; however, these agents can increase myocardial oxygen consumption, impair tissue perfusion, and are frequently ineffective. An alternative approach is to temporarily augment cardiac output using mechanical devices. The use of these devices-known as temporary circulatory support systems-has increased substantially in recent years, despite being expensive, resource intensive, associated with major complications, and lacking high-quality evidence to support their use. This Review summarises the physiological basis underlying the use of temporary circulatory support for cardiogenic shock, reviews the evidence informing indications and contraindications, addresses ethical considerations, and highlights the need for further research.

Prognostic Impact of Active Mechanical Circulatory Support in Cardiogenic Shock Complicating Acute Myocardial Infarction, Results from the Culprit-Shock Trial

OBJECTIVES

To analyze the use and prognostic impact of active mechanical circulatory support (MCS) devices in a large prospective contemporary cohort of patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI).

BACKGROUND

Although increasingly used in clinical practice, data on the efficacy and safety of active MCS devices in patients with CS complicating AMI are limited.

METHODS

This is a predefined subanalysis of the CULPRIT-SHOCK randomized trial and prospective registry. Patients with CS, AMI and multivessel coronary artery disease were categorized in two groups: (1) use of at least one active MCS device vs. (2) no active MCS or use of intra-aortic balloon pump (IABP) only. The primary endpoint was a composite of all-cause death or renal replacement therapy at 30 days.

RESULTS

Two hundred of 1055 (19%) patients received at least one active MCS device (n = 112 Impella^®; n = 95 extracorporeal membrane oxygenation (ECMO); n = 6 other devices). The primary endpoint occurred significantly more often in patients treated with active MCS devices compared with those without active MCS devices (142 of 197, 72% vs. 374 of 827, 45%; p < 0.001). All-cause mortality and bleeding rates were significantly higher in the active MCS group (all p < 0.001). After multivariable adjustment, the use of active MCS was significantly associated with the primary endpoint (odds ratio (OR) 4.0, 95% confidence interval (CI) 2.7-5.9; p < 0.001).

CONCLUSIONS

In the CULPRIT-SHOCK trial, active MCS devices were used in approximately one fifth of patients. Patients treated with active MCS devices showed worse outcome at 30 days and 1 year.

Mechanical assist devices for acute cardiogenic shock

BACKGROUND

Cardiogenic shock (CS) is a state of critical end-organ hypoperfusion due to a primary cardiac disorder. For people with refractory CS despite maximal vasopressors, inotropic support and intra-aortic balloon pump, mortality approaches 100%. Mechanical assist devices provide mechanical circulatory support (MCS) which has the ability to maintain vital organ perfusion, to unload the failing ventricle thus reduce intracardiac filling pressures which reduces pulmonary congestion, myocardial wall stress and myocardial oxygen consumption. This has been hypothesised to allow time for myocardial recovery (bridge to recovery) or allow time to come to a decision as to whether the person is a candidate for a longer-term ventricular assist device (VAD) either as a bridge to heart transplantation or as a destination therapy with a long-term VAD.

OBJECTIVES

To assess whether mechanical assist devices improve survival in people with acute cardiogenic shock.

SEARCH METHODS

We searched CENTRAL, MEDLINE (Ovid), Embase (Ovid) and Web of Science Core Collection in November 2019. In addition, we searched three trials registers in August 2019. We scanned reference lists and contacted experts in the field to obtain further information. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials on people with acute CS comparing mechanical assist devices with best current intensive care management, including intra-aortic balloon pump and inotropic support.

DATA COLLECTION AND ANALYSIS

We performed data collection and analysis according to the published protocol. Primary outcomes were survival to discharge, 30 days, 1 year and secondary outcomes included, quality of life, major adverse cardiovascular events (30 days/end of follow-up), dialysis-dependent (30 days/end of follow-up), length of hospital stay and length of intensive care unit stay and major adverse events. We used the five GRADE considerations (study limitations, consistency of effect, imprecision, indirectness, and publication bias) to assess the quality of a body of evidence as it relates to the studies which contribute data to the meta-analyses for the prespecified outcomes Summary statistics for the primary endpoints were risk ratios (RR), hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs).

MAIN RESULTS

The search identified five studies from 4534 original citations reviewed. Two studies included acute CS of all causes randomised to treatment using TandemHeart percutaneous VAD and three studies included people with CS secondary to acute myocardial infarction who were randomised to Impella CP or best medical management. Meta-analysis was performed only to assess the 30-day survival as there were insufficient data to perform any further meta-analyses. The results from the five studies with 162 participants showed mechanical assist devices may have little or no effect on 30-day survival (RR of 1.01 95% CI 0.76 to 1.35) but the evidence is very uncertain. Complications such as sepsis, thromboembolic phenomena, bleeding and major adverse cardiovascular events were not infrequent in both the MAD and control group across the studies, but these could not be pooled due to inconsistencies in adverse event definitions and reporting. We identified four randomised control trials assessing mechanical assist devices in acute CS that are currently ongoing.

AUTHORS' CONCLUSIONS

There is no evidence from this review of a benefit from MCS in improving survival for people with acute CS. Further use of the technology, risk stratification and optimising the use protocols have been highlighted as potential reasons for lack of benefit and are being addressed in the current ongoing clinical trials.

Mechanical circulatory support devices in cardiogenic shock and acute heart failure: current evidence

PURPOSE OF REVIEW

The main purpose of this review is to highlight and summarize recently published studies on the usage of short-term mechanical circulatory support devices for treatment of cardiogenic shock. Importantly, this review will focus on percutaneously implanted devices.

RECENT FINDINGS

In recent years, usage of active mechanical circulatory support devices, such as catheter-based left ventricular-assist devices and veno-arterial extracorporeal membrane oxygenation devices, has been widely adopted. Several device-specific strategies have been proposed to improve outcome of treated patients with cardiogenic shock, ranging from early identification and treatment of patients via dedicated shock protocols to combinatory usage of these devices. However, this is not supported by prospective, randomized trials but by retrospective analysis, which are significantly impacted by bias.

SUMMARY

Randomized, controlled trials are utterly needed to guide treatment with mechanical circulatory support for patients with cardiogenic shock. Importantly, such trials should focus patient selection criteria.