Extracorporeal Circulatory Support in Acute Coronary Syndromes: A Systematic Review and Meta-Analysis

Growing Evidence for LV Unloading in VA ECMO

Impressively increasing availability of mechanical circulatory/cardiac support systems (MCSs) worldwide, together with the deepening of the knowledge of critical care medical practitioners, has inevitably led to the discussion about further improvements of intensive care associated to MCS. An appealing topic of the left ventricle (LV) overload related to VA ECMO support endangering myocardial recovery is being widely discussed within the scientific community. Unloading of LV leads to the reduction in LV end-diastolic pressure, reduction in pressure in the left atrium, and decrease in the LV thrombus formation risk. Consequently, better conditions for myocardial recovery, with comfortable filling pressures and a better oxygen delivery/demand ratio, are achieved. The combination of VA ECMO and Impella device, also called ECPELLA, seems to be a promising strategy that may bring the improvement of CS mortality rates. The series of presented trials and meta-analyses clearly showed the potential benefits of this strategy. However, the ongoing research has brought a series of new questions, such as whether Impella itself is the only appropriate unloading modality, or any other approach to unload LV would be beneficial in the same way. Benefits and potential risks of LV unloading and its timing are being discussed in this current review.

Contemporary Management of Cardiogenic Shock Complicating Acute Myocardial Infarction

Despite an improvement in pharmacological therapies and mechanical reperfusion, the outcome of patients with acute myocardial infarction (AMI) is still suboptimal, especially in patients with cardiogenic shock (CS). The incidence of CS accounts for 3-15% of AMI cases, with mortality rates of 40% to 50%. In contrast to a large number of trials conducted in patients with AMI without CS, there is limited evidence-based scientific knowledge in the CS setting. Therefore, recommendations and actual treatments are often based on registry data. Similarly, knowledge of the available options in terms of temporary mechanical circulatory support (MCS) devices is not equally widespread, leading to an underutilisation or even overutilisation in different regions/countries of these treatment options and nonuniformity in the management of CS. The aim of this article is to provide a critical overview of the available literature on the management of CS as a complication of AMI, summarising the most recent evidence on revascularisation strategies, pharmacological treatments and MCS use.

Longitudinal Trends in Bleeding Complications on Extracorporeal Life Support Over the Past Two Decades—Extracorporeal Life Support Organization Registry Analysis

OBJECTIVES

Data about inhospital outcomes in bleeding complications during extracorporeal life support (ECLS) have been poorly investigated.

DESIGN

Retrospective observational study.

SETTING

Patients reported in Extracorporeal Life Support Organization Registry.

PATIENTS

Data of 53.644 adult patients (greater than or equal to 18 yr old) mean age 51.4 ± 15.9 years, 33.859 (64.5%) male supported with single ECLS run between 01.01.2000 and 31.03.2020, and 19.748 cannulated for venovenous (V-V) ECLS and 30.696 for venoarterial (V-A) ECLS.

INTERVENTIONS

Trends in bleeding complications, bleeding risk factors, and mortality.

MEASUREMENT AND MAIN RESULTS

Bleeding complications were reported in 14.786 patients (27.6%), more often in V-A ECLS compared with V-V (30.0% vs 21.9%; p < 0.001). Hospital survival in those who developed bleeding complications was lower in both V-V ECLS (49.6% vs 66.6%; p < 0.001) and V-A ECLS (33.9 vs 44.9%; p < 0.001). Steady decrease in bleeding complications in V-V and V-A ECLS was observed over the past 20 years (coef., -1.124; p < 0.001 and -1.661; p < 0.001). No change in mortality rates was reported over time in V-V or V-A ECLS (coef., -0.147; p = 0.442 and coef., -0.195; p = 0.139).Multivariate regression revealed advanced age, ecls duration, surgical cannulation, renal replacement therapy, prone positioning as independent bleeding predictors in v-v ecls and female gender, ecls duration, pre-ecls arrest or bridge to transplant, therapeutic hypothermia, and surgical cannulation in v-a ecls.

CONCLUSIONS

A steady decrease in bleeding over the last 20 years, mostly attributable to surgical and cannula-site-related bleeding has been found in this large cohort of patients receiving ECLS support. However, there is not enough data to attribute the decreasing trends in bleeding to technological refinements alone. Especially reduction in cannulation site bleeding is also due to changes in timing, patient selection, and ultrasound guided percutaneous cannulation. Other types of bleeding, such as CNS, have remained stable, and overall bleeding remains associated with a persistent increase in mortality.

Predictors of mortality following extracorporeal membrane oxygenation support in an unselected, critically ill patient population

Introduction

Mechanical circulatory support (MCS) has been established as a means of augmenting circulation in patients with critically decreased systolic function due to a variety of underlying clinical reasons. Different methods of MCS may be used, with the venous-arterial extracorporeal membrane oxygenation system (VA-ECMO) being one of the most utilized devices in everyday care.

Aim

To determine independent predictors influencing mortality outcomes following VA-ECMO therapy in a large, unselected, adult, critically ill patient population in cardiogenic shock (CS).

Material and methods

Data on 235 consecutive, real-world VA-ECMO treatments were assessed. Analysis was conducted for all subjects requiring MCS with the VA-ECMO as the first instalment, regardless of underlying cause or eventual upgrade. All potential clinical factors influencing mortality were examined and evaluated.

Results

Overall mortality was ~66% at median 28 days follow-up and significantly depended upon pH < 7.3 (HR = 3.56; p < 0.001), and age ≥ 65 years (HR = 1.96; p = 0.001). Acute coronary syndrome (ACS) as an indication for VA-ECMO displayed a nearly significant value (HR = 1.44; p = 0.07). Heart transplant (hTX) primary graft failure as an indication for the VA-ECMO displayed a clearly favorable outcome (HR = 0.51, p = 0.025); all data based on multivariate Cox regression analysis.

Conclusions

Mortality in patients requiring VA-ECMO remains high. We conclude that only decreased pH values and advanced age clearly influence mortality in this MCS scenario. ACS also bodes unfavorably, whereas hTX as an indication clearly shows better survival.

Efficacy and safety of Impella 5.0 in cardiogenic shock: an updated systematic review

Aim: The impact on safety and efficacy outcomes of Impella 5.0 in cardiogenic shock (CS) has not been systematically assessed. Materials & methods: We conducted a systematic review of the literature (PROSPERO protocol: CRD42020164680) to critically appraise available evidence on Impella 5.0 comparative safety, efficacy and effectiveness. Results: Of 244 retrieved citations, 17 original articles met the a priori defined inclusion criteria. All included studies had a retrospective study design and, overall, reported on, respectively, 52 and 67 different safety and efficacy/effectiveness outcomes. Thirty-day survival rates ranged from 40 to 94%, myocardial recovery from 18 to 93%. Conclusion: Impella 5.0 provides a full cardiac support, it is associated with a lower rate of vascular complications, it represents a valuable bridge-to-decision and allows for resolution of intercurrent clinical conditions. As available data suggest Impella 5.0 good performance in CS of various etiologies, more solid evidence will come from much-needed large-scale all-comer registries and prospective multicenter randomized trials.

The effect of the localisation of an underlying ST-elevation myocardial infarction on the VF-waveform: A multi-centre cardiac arrest study

INTRODUCTION

In cardiac arrest, ventricular fibrillation (VF) waveform characteristics such as amplitude spectrum area (AMSA) are studied to identify an underlying myocardial infarction (MI). Observational studies report lower AMSA-values in patients with than without underlying MI. Moreover, experimental studies with 12-lead ECG-recordings show lowest VF-characteristics when the MI-localisation matches the ECG-recording direction. However, out-of-hospital cardiac arrest (OHCA)-studies with defibrillator-derived VF-recordings are lacking.

METHODS

Multi-centre (Amsterdam/Nijmegen, the Netherlands) cohort-study on the association between AMSA, ST-elevation MI (STEMI) and its localisation. AMSA was calculated from defibrillator pad-ECG recordings (proxy for lead II, inferior vantage point); STEMI-localisation was determined using ECG/angiography/autopsy findings.

RESULTS

We studied AMSA-values in 754 OHCA-patients. There were statistically significant differences between no STEMI, anterior STEMI and inferior STEMI (Nijmegen: no STEMI 13.0mVHz [7.9-18.6], anterior STEMI 7.5mVHz [5.6-13.8], inferior STEMI 7.5mVHz [5.4-11.8], p = 0.006. Amsterdam: 11.7mVHz [5.0-21.9], 9.6mVHz [4.6-17.2], and 6.9mVHz [3.2-16.0], respectively, p = 0.001). Univariate analyses showed significantly lower AMSA-values in inferior STEMI vs. no STEMI; there was no significant difference between anterior and no STEMI. After correction for confounders, adjusted absolute AMSA-values were numerically lowest for inferior STEMI in both cohorts, and the relative differences in AMSA between inferior and no STEMI was 1.4-1.7 times larger than between anterior and no STEMI.

CONCLUSION

This multi-centre VF-waveform OHCA-study showed significantly lower AMSA in case of underlying STEMI, with a more pronounced difference for inferior than for anterior STEMI. Confirmative studies on the impact of STEMI-localisation on the VF-waveform are warranted, and might contribute to earlier diagnosis of STEMI during VF.

Effects of mechanical circulatory support devices in patients with acute myocardial infarction undergoing stent implantation: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

The survival benefit of using mechanical circulatory support (MCS) in patients with acute myocardial infarction (AMI) is still controversial. It is necessary to explore the impact on clinical outcomes of MCS in patients with AMI undergoing stenting.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Embase, Cochrane Library, Medline, PubMed, Web of Science, ClinicalTrials.gov and Clinicaltrialsregister.eu databases were searched from database inception to February 2021.

ELIGIBILITY CRITERIA

Randomised clinical trials (RCTs) on MCS use in patients with AMI undergoing stent implantation were included.

DATA EXTRACTION AND SYNTHESIS

Data were extracted and summarised independently by two reviewers. Risk ratios (RRs) and 95% CIs were calculated for clinical outcomes according to random-effects model.

RESULTS

Twelve studies of 1497 patients with AMI were included, nine studies including 1382 patients compared MCS with non-MCS, and three studies including 115 patients compared percutaneous ventricular assist devices (pVADs) versus intra-aortic balloon pump (IABP). Compared with non-MCS, MCS was not associated with short-term (within 30 days) (RR=0.90; 95% CI 0.57 to 1.41; I²=46.8%) and long-term (at least 6 months) (RR=0.82; 95% CI 0.57 to 1.17; I²=37.6%) mortality reductions. In the subset of patients without cardiogenic shock (CS) compared with non-MCS, the patients with IABP treatment significantly had decreased long-term mortality (RR=0.49; 95% CI 0.27 to 0.90; I²=0), but without the short-term mortality reductions (RR=0.51; 95% CI 0.22 to 1.19; I²=17.9%). While in the patients with CS, the patients with MCS did not benefit from the short-term (RR=1.09; 95% CI 0.67 to 1.79; I²=46.6%) or long-term (RR=1.00; 95% CI 0.75 to 1.33; I²=22.1%) survival. Moreover, the application of pVADs increased risk of bleeding (RR=1.86; 95% CI 1.15 to 3.00; I²=15.3%) compared with IABP treatment (RR=1.86; 95% CI 1.15 to 3.00; I²=15.3%).

CONCLUSIONS

In all patients with AMI undergoing stent implantation, the MCS use does not reduce all-cause mortality. Patients without CS can benefit from MCS regarding long-term survival, while patients with CS seem not.

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.

Epidemiology and Clinical Characteristics of Bloodstream Infection in Patients Under Extracorporeal Membranous Oxygenation

BACKGROUND

Bloodstream infection (BSI) is an important complication of extracorporeal membranous oxygenation (ECMO) and a major cause of mortality. This study evaluated the epidemiological and clinical characteristics of BSI that occur during ECMO application according to microbial etiology.

METHODS

Adult patients who underwent ECMO from January 2009 to December 2016 were retrospectively analyzed for BSI episodes at a 2,700-bed, tertiary center. Epidemiological and clinical characteristics and outcomes of BSI were evaluated and were compared for etiologic groups (gram-positive cocci, gram-negative rods, and fungi groups). Risk factors for 14-day mortality were analyzed.

RESULTS

A total of 1,100 patients underwent ECMO during the study period, and 65 BSI episodes occurred in 61 patients. The BSI incidence was 8.3 episodes/1,000 ECMO days, which significantly decreased over time (P = 0.03), primarily in gram-positive cocci BSI. Gram-positive cocci, gram-negative rods, and fungi accounted for 38%, 40%, and 22% of the 73 blood isolates, respectively. Baseline characteristics were comparable between groups. Catheter-related infection (CRI) and pneumonia were the most common sources of BSI; 52% of gram-positive cocci BSIs and 79% of fungi BSIs were caused by CRI, and 75% of gram-negative BSIs by pneumonia. Patients with gram-negative rods BSI died more frequently and earlier than those with other BSIs. Independent risk factors for 14-day mortality were older age and gram-negative rods BSI.

CONCLUSIONS

The decreased BSI incidence during ECMO was mainly because of the decrease of gram-positive cocci BSI. The high early mortality of gram-negative rods BSI makes prevention and adequate treatment necessary.

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.

Predictors of complications associated with extracorporeal membrane oxygenation

OBJECTIVES

to identify in the literature, the predictors of ECMO complications in adult patients.

METHODS

integrative review of literature, including articles in Portuguese, English and Spanish published from 2014 to 2018 in five databases. Included articles which analyzed the predictive factors of ECMO complications in adult patients using multivariate analysis.

RESULTS

a total of 1629 articles were identified, of which 19 were included. Nineteen predictors were identified for neurological complications (e.g., post-ECMO hypoglycemia), seven for bleeding complications (e.g., fungal pneumonia), four for infections complications (e.g., preoperative creatinine level), three for kidney complications (e.g., the length of ICU stay> 20 days) and a combination of factors for mechanical complications (e.g., median flow).

CONCLUSIONS

different predictors were identified to ECMO complications. The knowledge of these predictors enables the individualized targeting of preventive interventions by multidisciplinary team for modifiable factors, as well as intensification of monitoring for early recognition of non-modifiable factors.

Antithrombotic therapy in patients with acute coronary syndrome complicated by cardiogenic shock or out-of-hospital cardiac arrest: a joint position paper from the European Society of Cardiology (ESC) Working Group on Thrombosis, in association with the Acute Cardiovascular Care Association (ACCA) and European Association of Percutaneous Cardiovascular Interventions (EAPCI)

Timely and effective antithrombotic therapy is critical to improving outcome, including survival, in patients with acute coronary syndrome (ACS). Achieving effective platelet inhibition and anticoagulation, with minimal risk, is particularly important in high-risk ACS patients, especially those with cardiogenic shock (CS) or those successfully resuscitated following out-of-hospital cardiac arrest (OHCA), who have a 30-50% risk of death or a recurrent ischaemic event over the subsequent 30 days. There are unique challenges to achieving effective and safe antithrombotic treatment in this cohort of patients that are not encountered in most other ACS patients. This position paper focuses on patients presenting with CS or immediately post-OHCA, of presumed ischaemic aetiology, and examines issues related to thrombosis and bleeding risk. Both the physical and pharmacological impacts of CS, namely impaired drug absorption, metabolism, altered distribution and/or excretion, associated multiorgan failure, co-morbidities and co-administered treatments such as opiates, targeted temperature management, renal replacement therapy and circulatory or left ventricular assist devices, can have major impact on the effectiveness and safety of antithrombotic drugs. Careful attention to the choice of antithrombotic agent(s), route of administration, drug-drug interactions, therapeutic drug monitoring and factors that affect drug efficacy and safety, may reduce the risk of sub- or supra-therapeutic dosing and associated adverse events. This paper provides expert opinion, based on best available evidence, and consensus statements on optimising antithrombotic therapy in these very high-risk patients, in whom minimising the risk of thrombosis and bleeding is critical to improving outcome.

Extracorporeal Membrane Oxygenation Use in Cardiogenic Shock: Impact of Age on In-Hospital Mortality, Length of Stay, and Costs

OBJECTIVES

Increasing age is a well-recognized risk factor for in-hospital mortality in patients receiving extracorporeal membrane oxygenation for cardiogenic shock, but the shape of this relationship is unknown. In addition, the impact of age on hospital length of stay, patterns of patient disposition, and costs has been incompletely characterized.

DESIGN

Retrospective analysis of the National Inpatient Sample.

SETTING

U.S. nonfederal hospitals, years 2004-2016.

PATIENTS

Adults with cardiogenic shock treated with extracorporeal membrane oxygenation (3,094; weighted national estimate: 15,415).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The mean age of extracorporeal membrane oxygenation recipients was 54.8 ± 15.4 years (range, 18-90 yr). Crude in-hospital mortality was 57.7%. Median time-to-death was 8 days (interquartile range, 3-17 d). A linear relationship between age and in-hospital mortality was observed with a 14% increase in the adjusted odds of in-hospital mortality for every 10-year increase in age (adjusted odds ratio, 1.14; 95% CI, 1.08-1.21; p < 0.0001). Thirty-four percent of patients were discharged alive at a median time of 30 days (interquartile range, 19-48 d). The median length of stay and total hospitalization costs were 14 days (interquartile range, [5-29 d]) and $134,573 ($71,782-$239,439), respectively, both of which differed significantly by age group (length of stay range from 17 d [18-49 yr] to 9 d [80-90 yr]; p < 0.0001 and cost range $147,548 [18-49 yr] to $105,350 [80-90 yr]; p < 0.0001).

CONCLUSIONS

Age is linearly associated with increasing in-hospital mortality in individuals receiving extracorporeal membrane oxygenation for cardiogenic shock without evidence of a threshold effect. Median time-to-death is approximately 1 week. One third of patients are discharged from the hospital alive, but the median time-to-discharge is 1 month. Median length of stay ranges from 9 to 17 days depending on age. Hospitalization costs exceed $100,000 in all age groups.

Developments to monitor the exhalome in organ failure in critically ill patients-a look into the future

Critically ill patients typically need some kind of functional organ support or replacement. Cardiopulmonary and renal replacement therapies are well established measures in intensive care units. However, there are also inherent risks associated with these treatments. The appropriate and timely commencement, maintenance and termination of organ replacement procedures currently use weak surrogates as decision support in clinical practice. A more reasonable application of extracorporeal organ support can be expected to potentially lower adverse events and save costs in healthcare systems, if a precise online monitoring was available. The analysis of the exhalome offers great opportunities to detect circulatory, pulmonary, and renal failure in critically ill patients. Volatile organic compounds and exhalation patterns are associated with a series of metabolic disorders and may be key to indicate the appropriate time point for initiation, maintenance and termination of organ support technologies. It may thus be expected that mortality, infection risk, replacement therapy days, and medical costs of intensive care treatment may possibly be reduced using exhalome analysis for control of organ replacement therapies in the distant future.

Outcomes of Impella 5.0 in Cardiogenic Shock

Objective

The aim of the study was to comprehensively summarize the survival outcomes and complications of Impella 5.0 (Abiomed Inc, Danvers, MA USA) use in patients with cardiogenic shock (CS).

Methods

We performed a literature review for relevant studies by searching in Medline, Medline In-Process, EMBASE, and the CENTRAL bibliographic databases on April 30, 2017. Nonoverlapping studies with 10 patients or more supported for cardiogenic shock with Impella 5.0 or Impella left direct were included. Data on patient characteristics, indication of support, and outcomes were extracted. A random effect was used to pool the various outcomes.

Results

This meta-analysis included six studies totaling 163 patients (mean ± SD age = 56.3 ± 12.0, male 81%). Indications for support included 88 (54.0%) for acute on chronic decompensated heart failure, 35 (21.5%) for postcardiotomy cardiogenic shock, 27 (16.6%) for acute myocardial infarction complicated by cardiogenic shock, and, 13 (8.0%) for cardiogenic shock due to other reasons. Survival to next therapy was 73.5% in patients supported for acute on chronic decompensated heart failure. The survival to device explant among patients supported for postcardiotomy cardiogenic shock or acute myocardial infarction complicated by cardiogenic shock was 90.2%, and of those, myocardial recovery was achieved in 73.8%. The overall estimated survival to discharge, 30, 180, and 365 days was 73.5%, 72.6%, 62.7%, and 58.4%, respectively. Patients supported for postcardiotomy cardiogenic shock had the highest heart recovery among survivors to explant (92.1%) and highest survival at 30 (89.5%) and 365 days (69.5%).

Conclusions

Impella 5.0/LD is associated with favorable survival outcomes and higher rate of myocardial recovery in patients with cardiogenic shock.

[Organ assist devices in the future : Limits and perspectives]

In the last decade, extracorporeal organ assist devices (extracorporeal membrane oxygenation [ECMO]) have been increasingly applied to treat the most severe forms of respiratory failure and cardiogenic shock, although the underlying scientific evidence is still limited and the methods carry a high risk of complications despite all technical improvements. The selection of those patients who most benefit from these devices is still a great challenge for intensivists and all other involved disciplines. Besides the severity of the acute organ failure, it is important to thoroughly evaluate etiology and treatment options of the underlying disease, comorbidities, and the functional status of the patients in an interdisciplinary team. This also includes ethical challenges. Because of the complexity of the treatment and the high organizational demands it is reasonable to concentrate ECMO treatments in specifically qualified centers and to promote a comprehensive scientific analysis of the treatment data.