Extracorporeal Membrane Oxygenation for Advanced Refractory Shock in Acute and Chronic Cardiomyopathy

Case Report: Extended cardiopulmonary resuscitation in sudden cardiac arrest after acute myocardial infarction

Out-of-hospital cardiac arrest (OHCA) mostly occurs in crowded public places outside hospitals, such as public sports facilities, airports, railway stations, subway stations, and shopping malls. The emergency department of Liaocheng People's Hospital in Shandong Province admitted one patient with OHCA in August 2021, who suddenly suffered a loss of consciousness and cardiac arrest during exercise after dinner. Witnesses immediately gave continuous chest compressions and artificial respiration and called our hospital's emergency department (at 120). Arriving at the emergency department, we continued to provide chest compressions and ventilator-assisted ventilation after performing endotracheal intubation. We administered adrenaline for cardiac excitation, dopamine for maintained blood pressure, sodium bicarbonate to correct the acidosis, and multiple electric defibrillations. However, the patient's cardiac Doppler ultrasound indicated poor cardiac contractions, and extracorporeal membrane oxygenation (ECMO) was started immediately. We performed coronary angiography for the patient with ECMO support, indicating that the patient had an 80% critical stenosis of the left main coronary artery and an 80%-90% stenosis in the middle section of the left anterior descending artery with an aneurysm. Fortunately, there was no obvious stenosis in the right coronary artery. The patient was transferred to the intensive care unit and received comprehensive treatment, including anticoagulation, myocardial nutritional support, improvement of cardiac function, continuous renal replacement therapy, organ function protection, anti-inflammatory treatment, and rehabilitation. Coronary artery bypass grafting was performed after the patient's condition stabilized, and he was finally discharged. ECMO support therapy for patients with cardiac arrest can be considered when economic conditions permit. It is very important to conduct the necessary examinations in the early stage of resuscitation with ECMO support to clarify the cause of the cardiac arrest and to treat it accordingly.

High incidence of acute kidney injury in extracorporeal resuscitation, Leading to poor prognosis

Background

Extracorporeal membrane oxygenation (ECMO) patients have a high incidence of acute kidney injury (AKI). Extracorporeal cardiopulmonary resuscitation (ECPR) patients are more likely to develop AKI than ECMO patients because of serious injury during cardiac arrest (CA).

Objectives

This study aims to assess the occurrence and outcomes of AKI in ECPR and ECMO, and to identify specific risk factors and clinical implications of AKI in ECPR.

Methods

This is a retrospective observational study from a single tertiary care hospital in Gwangju, Korea. Adults (≥18 years) who received ECMO with cardiac etiology in the emergency and inpatient departments from January 2015 to December 2021 were included. The patients (n = 169) were divided into two groups, ECPR and ECMO without CA, and the occurrence of AKI was investigated. The primary outcome of the study was in-hospital mortality, and the secondary outcomes were six-month cerebral performance category (CPC) and AKI during hospitalization.

Results

The incidence of AKI was significantly higher with ECPR (67.5 %) than with ECMO without CA (38.4 %). ECPR was statistically significant for Expire (adjusted OR (aOR) 2.45, 95 % CI 1.28-4.66) and Poor CPC (2.59, 1.32-5.09). AKI was also statistically significant for Expire (6.69, 3.37-13.29) and Poor CPC (5.45, 2.73-10.88). AKI was the determining factor for the outcomes of ECPR (p = 0.01).

Conclusions

ECPR patients are more likely to develop AKI than ECMO without CA patients. In ECPR patients, AKI leads to poor outcomes. Therefore, clinicians should be careful not to develop AKI in ECPR patients.

Patients with fulminant myocarditis supported with veno-arterial extracorporeal membrane oxygenation: a systematic review and meta-analysis of short-term mortality and impact of risk factors

Fulminant myocarditis (FM) may lead to cardiogenic shock requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Results of effectiveness studies of VA-ECMO have been contradictory. We evaluated the aggregate short-term mortality after VA-ECMO and predictive factors in patients with FM. We systematically searched in electronic databases (February 2022) to identify studies evaluating short-term mortality (defined as mortality at 30 days or in-hospital) after VA-ECMO support for FM. We included studies with 5 or more patients published after 2009. We assessed the quality of the evidence using the QUIPS and GRADE tools. Mortality was pooled using random effect models. We performed meta-regression to explore heterogeneity based on a priori defined factors. We included 54 observational studies encompassing 2388 FM patients supported with VA-ECMO. Median age was 41 years (25th to 75th percentile 37-47), and 50% were female. The pooled short-term mortality was 35% (95% CI 29-40%, I² = 69%; moderate certainty). By meta-regression, studies with younger populations showed lower mortality. Female sex, receiving a biopsy, cardiac arrest, left ventricular unloading, and earlier recruitment time frame, did not explain heterogeneity. These results remained consistent regardless of continent and the risk of bias category. In individual studies, low pH value, high lactate, absence of functional cardiac recovery on ECMO, increased burden of malignant arrhythmia, high peak coronary markers, and IVIG use were identified as independent predictors of mortality. When conventional therapies have failed, especially in younger patients, cardiopulmonary support with VA-ECMO should be considered in the treatment of severe FM.

Intraoperative Management of Adult Patients on Extracorporeal Membrane Oxygenation: An Expert Consensus Statement From the Society of Cardiovascular Anesthesiologists-Part I, Technical Aspects of Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is used to support patients with refractory cardiopulmonary failure. Given ECMO's increased use in adults and the fact that many ECMO patients are cared for by anesthesiologists, the Society of Cardiovascular Anesthesiologists ECMO working group created an expert consensus statement that is intended to help anesthesiologists manage adult ECMO patients who are cared for in the operating room. In the first part of this 2-part series, technical aspects of ECMO are discussed, and related expert consensus statements are provided.

Proposal for a trial of early left ventricular venting during venoarterial extracorporeal membrane oxygenation for cardiogenic shock

Objective

Patients with profound cardiogenic shock may require venoarterial (VA) extracorporeal membrane oxygenation (ECMO) for circulatory support most commonly via the femoral vessels. The rate of cardiac recovery in this population remains low, possibly because peripheral VA-ECMO increases ventricular afterload. Whether direct ventricular unloading in peripheral VA-ECMO enhances cardiac recovery is unknown, but is being more frequently utilized. A randomized trial is warranted to evaluate the clinical effectiveness of percutaneous left ventricle venting to enhance cardiac recovery in the setting of VA-ECMO.

Methods

We describe the rationale, design, and initial testing of a randomized controlled trial of VA-ECMO with and without percutaneous left ventricle venting using a percutaneous micro-axial ventricular assist device.

Results

This is an ongoing prospective randomized controlled trial in adult patients with primary cardiac failure presenting in cardiogenic shock requiring peripheral VA-ECMO, designed to test the safety and effectiveness of percutaneous left ventricle venting in improving the rate of cardiac recovery.

Conclusions

The results of this nonindustry-sponsored trial will provide critical information on whether left ventricle unloading in peripheral VA-ECMO is safe and effective.

Intraoperative Management of Adult Patients on Extracorporeal Membrane Oxygenation: an Expert Consensus Statement From the Society of Cardiovascular Anesthesiologists-Part I, Technical Aspects of Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is used to support patients with refractory cardiopulmonary failure. Given ECMO's increased use in adults and the fact that many ECMO patients are cared for by anesthesiologists, the Society of Cardiovascular Anesthesiologists ECMO working group created an expert consensus statement that is intended to help anesthesiologists manage adult ECMO patients who are cared for in the operating room. In the first part of this 2-part series, technical aspects of ECMO are discussed, and related expert consensus statements are provided.

Comparison of Impella 5.0 and extracorporeal left ventricular assist device in patients with cardiogenic shock

INTRODUCTION

Choice of mechanical circulatory support to stabilize hemodynamics until cardiac recovery or next treatment is a strategic cornerstone for improving outcomes in patients with severe cardiogenic shock. We aimed to clarify the difference in treatment course and outcomes with the use of Impella 5.0 and an extracorporeal left ventricular assist device (eLVAD) in patients with cardiogenic shock refractory to medical therapy or other mechanical circulatory support.

METHODS

We performed a retrospective medical record review of consecutive patients who were implanted with Impella 5.0 or eLVAD as a bridge to decision at our medical center.

RESULTS

A total of 26 patients (median age 40 years, 16 males) were analyzed. Of seven patients managed with Impella 5.0, the Impella 5.0 was removed successfully in two patients and five patients underwent surgery for durable LVAD implantation. Of 19 patients managed with eLVAD, the eLVAD was successfully removed in 3 patients, 9 patients required durable LVAD, and 7 patients died during eLVAD management. The period between Impella 5.0 or eLVAD implantation to durable LVAD surgery was significantly shorter with Impella 5.0 (58 vs 235 days, p = 0.001). Cardiopulmonary bypass time was significantly shorter and a significantly smaller amount of red blood cell transfusion was required with Impella 5.0 (149 vs 192 min, p = 0.042; 7.0 vs 15.0 units, p = 0.019). There were four massive stroke events with eLVAD, but no massive stroke event with Impella 5.0.

CONCLUSION

Impella 5.0 facilitates smoother management as a bridge to decision and reduces surgical invasiveness during durable LVAD implantation.

Understanding the "extracorporeal membrane oxygenation gap" in veno-arterial configuration for adult patients: Timing and causes of death

Timing and causes of hospital mortality in adult patients undergoing veno‐arterial extracorporeal membrane oxygenation (V‐A ECMO) have been poorly described. Aim of the current review was to investigate the timing and causes of death of adult patients supported with V‐A ECMO and subsequently define the “V‐A ECMO gap,” which represents the patients who are successfully weaned of ECMO but eventually die during hospital stay. A systematic search was performed using electronic MEDLINE and EMBASE databases through PubMed. Studies reporting on adult V‐A ECMO patients from January 1993 to December 2020 were screened. The studies included in this review were studies that reported more than 10 adult, human patients, and no mechanical circulatory support other than V‐A ECMO. Information extracted from each study included mainly mortality and causes of death on ECMO and after weaning. Complications and discharge rates were also extracted. Sixty studies with 9181 patients were included for analysis in this systematic review. Overall mortality was 38.0% (95% confidence intervals [CIs] 34.2%‐41.9%) during V‐A ECMO support (reported by 60 studies) and 15.3% (95% CI 11.1%‐19.5%, reported by 57 studies) after weaning. Finally, 44.0% of patients (95% CI 39.8‐52.2) were discharged from hospital (reported by 60 studies). Most common causes of death on ECMO were multiple organ failure, followed by cardiac failure and neurological causes. More than one‐third of V‐A ECMO patients die during ECMO support. Additionally, many of successfully weaned patients still decease during hospital stay, defining the “V‐A ECMO gap.” Underreporting and lack of uniformity in reporting of important parameters remains problematic in ECMO research. Future studies should uniformly define timing and causes of death in V‐A ECMO patients to better understand the effectiveness and complications of this support.

Outcomes of temporary mechanical circulatory support in cardiogenic shock due to end-stage heart failure

Background

There are few reports of mechanical circulatory support (MCS) in patients with cardiogenic shock (CS) due to end-stage heart failure (ESHF). We evaluated our institutional MCS strategy and compared the outcomes of INTERMACS 1 and 2 patients with CS due to ESHF.

Methods

Retrospective analysis of prospectively collected data (November 2014 to July 2019) from a single centre. ESHF was defined by a diagnosis of HF prior to presentation with CS. Other causes of CS (eg: acute myocardial infarction) were excluded. We compared the clinical course, complications and 90-day survival of patients with CS due to ESHF in INTERMACS profile 1 and 2.

Results

We included 60 consecutive patients with CS due to ESHF Differences in baseline characteristics were consistent with the INTERMACS profiles. The duration of MCS was similar between INTERMACS 1 and 2 patients (14 (10–33) vs 15 (7–23) days, p = 0.439). There was no significant difference in the number of patients with complications that required intervention. Compared to INTERMACS 2, INTERMACS 1 patients had more organ dysfunction on support and significant lower 90-day survival (66% vs 34%, p = 0.016).

Conclusion

Our temporary MCS strategy, including earlier intervention in patients with CS due to ESHF at INTERMACS 2 was associated with less organ dysfunction and better 90-day survival compared to INTERMACS 1 patients.

Coronary Artery Bypass Grafting in Cardiogenic Shock: Decision-Making, Management Options, and Outcomes

Coronary artery bypass grafting is a highly efficacious mode of myocardial revascularization that reduces mortality from ischemic heart disease. The patient presenting after acute myocardial infarction in cardiogenic shock presents a unique challenge. Early revascularization is proven to reduce mortality, but many questions remain, including the optimal mode and extent of revascularization, the role of mechanical circulatory support, and which patients are candidates for surgical intervention. Unprecedented attention to the outcomes of cardiac surgery means decisions about the management of the acute myocardial infarction in cardiogenic shock patients are influenced by risk aversion. The authors here review this topic to arm the reader with a comprehensive understanding of the literature to better guide surgical decision-making and perioperative management.

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.

Predictors of Survival for Patients with Acute Decompensated Heart Failure Requiring Extra-Corporeal Membrane Oxygenation Therapy

Chronic systolic heart failure (HF) with acute decompensation can result in cardiogenic shock (CS) requiring short-term mechanical circulatory support. We sought to identify predictors of survival for acute decompensated HF (ADHF) patients requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Patients >18 years old treated at our institution with VA-ECMO from 2009 to 2018 for ADHF with CS were studied. Demographic, hemodynamic, and echocardiographic data were collected. The primary outcome was survival to discharge. Fifty-two patients received VA-ECMO for ADHF with CS; 24 (46.2%) survived. Seventeen (32.7%) had suffered cardiac arrest, and 37 (71.2%) were mechanically ventilated. Mean lactate was 4.33 ± 3.45 mmol/L, and patients were receiving 2.7 ± 1.2 vasopressor/inotropic infusions at ECMO initiation; these did not differ significantly between survivors and nonsurvivors. Pre-ECMO cardiac index was 1.84 ± 0.56L/min/m and 1.94 ± 0.63L/min/m in survivors and nonsurvivors, respectively (p = 0.57). In multivariable analysis, only diabetes mellitus (DM; OR, 13.25; CI, 1.42-123.40; p = 0.02) and mineralocorticoid receptor antagonist use (OR, 0.12; CI, 0.02-0.78; p = 0.03) were independent predictors of mortality. Nineteen (79.2%) survivors required durable ventricular assist device. Among ADHF patients receiving VA-ECMO, DM is a powerful predictor of outcomes while markers of clinical acuity including hemodynamics, vasopressor/inotrope use, and lactate are not. The vast majority of survivors required durable left-ventricular assist devices.

Extracorporeal Membrane Oxygenation Use in Acute Myocardial Infarction in the United States, 2000 to 2014

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly used in acute myocardial infarction (AMI); however, there are limited large-scale national data.

METHODS

Using the National Inpatient Sample database from 2000 to 2014, a retrospective cohort of AMI utilizing ECMO was identified. Use of percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous left ventricular assist device (LVAD) was also identified in this population. Outcomes of interest included temporal trends in utilization of ECMO alone and with concomitant procedures (percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous LVAD), in-hospital mortality, and resource utilization.

RESULTS

In ≈9 million AMI admissions, ECMO was used in 2962 (<0.01%) and implanted a median of 1 day after admission. ECMO was used in 0.5% and 0.3% AMI admissions complicated by cardiogenic shock and cardiac arrest, respectively. ECMO was used more commonly in admissions that were younger, nonwhite, and with less comorbidity. ECMO use was 11× higher in 2014 as compared with 2000 (odds ratio, 11.37 [95% CI, 7.20-17.97]). Same-day percutaneous coronary intervention was performed in 23.1%; intra-aortic balloon pump/percutaneous LVAD was used in 57.9%, of which 30.3% were placed concomitantly. In-hospital mortality with ECMO was 59.2% overall but decreased from 100% (2000) to 45.1% (2014). Durable LVAD and cardiac transplantation were performed in 11.7% as an exit strategy. Of the hospital survivors, 40.8% were discharged to skilled nursing facilities. Older age, male sex, nonwhite race, and lower socioeconomic status were independently associated with higher in-hospital mortality with ECMO use.

CONCLUSIONS

In AMI admissions, a steady increase was noted in the utilization of ECMO alone and with concomitant procedures (percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous LVAD). In-hospital mortality remained high in AMI admissions treated with ECMO.

Optimal Strategy and Timing of Left Ventricular Venting During Veno-Arterial Extracorporeal Life Support for Adults in Cardiogenic Shock

Background:

Veno-arterial extracorporeal life support (VA-ECLS) is widely used to treat refractory cardiogenic shock. However, increased left ventricular (LV) afterload in VA-ECLS can worsen pulmonary congestion and compromise myocardial recovery. Our objectives were to explore the efficacy, safety, and optimal timing of adjunctive LV venting strategies.

Methods:

A systematic search was performed on Medline, EMBASE, PubMed, CDSR, CCRCT, CINAHL, ClinicalTrials.Gov, and WHO ICTRP from inception until January 2019 for all relevant studies, including LV venting. Data were analyzed for mortality and weaning from VA-ECLS on the basis of timing of LV venting, along with adverse complications.

Results:

A total of 7995 patients were included from 62 observational studies, wherein 3458 patients had LV venting during VA-ECLS. LV venting significantly improved weaning from VA-ECLS (odds ratio, 0.62 [95% CI, 0.47–0.83]; P =0.001) and reduced short-term (30 day; risk ratio [RR], 0.86 [95% CI, 0.77–0.96]; P =0.008) but not in-hospital (RR, 0.92 [95% CI, 0.83–1.01] P =0.09) or long-term (6 months; RR, 0.96 [95% CI, 0.90–1.03]; P =0.27) mortality. Early (<12 hours; RR, 0.86 [95% CI, 0.75–0.99]; P =0.03) but not late (≥12 hours; RR, 0.99 [95% CI, 0.71–1.38]; P =0.93) LV venting significantly reduced short-term mortality. Patients with LV venting spent more time on VA-ECLS (3.6 versus 2.8 days, P <0.001), and mechanical ventilation (7.1 versus 4.6 days, P =0.013). With the exception of hemolysis (RR, 2.18 [95% CI, 1.58–3.01]; P <0.00001), overall adverse events did not differ.

Conclusions:

LV venting, especially if done early (<12 hours), appears to be associated with an increased success of weaning and reduced short-term mortality. Future studies are required to delineate the importance of any or early LV venting adjuncts on mortality and morbidity outcomes.

Incidence and Impact of Acute Kidney Injury in Patients Receiving Extracorporeal Membrane Oxygenation: A Meta-Analysis

BACKGROUND

Although acute kidney injury (AKI) is a frequent complication in patients receiving extracorporeal membrane oxygenation (ECMO), the incidence and impact of AKI on mortality among patients on ECMO remain unclear. We conducted this systematic review to summarize the incidence and impact of AKI on mortality risk among adult patients on ECMO.

METHODS

A literature search was performed using EMBASE, Ovid MEDLINE, and Cochrane Databases from inception until March 2019 to identify studies assessing the incidence of AKI (using a standard AKI definition), severe AKI requiring renal replacement therapy (RRT), and the impact of AKI among adult patients on ECMO. Effect estimates from the individual studies were obtained and combined utilizing random-effects, generic inverse variance method of DerSimonian-Laird. The protocol for this systematic review is registered with PROSPERO (no. CRD42018103527).

RESULTS

41 cohort studies with a total of 10,282 adult patients receiving ECMO were enrolled. Overall, the pooled estimated incidence of AKI and severe AKI requiring RRT were 62.8% (95%CI: 52.1%-72.4%) and 44.9% (95%CI: 40.8%-49.0%), respectively. Meta-regression showed that the year of study did not significantly affect the incidence of AKI (p = 0.67) or AKI requiring RRT (p = 0.83). The pooled odds ratio (OR) of hospital mortality among patients receiving ECMO with AKI on RRT was 3.73 (95% CI, 2.87-4.85). When the analysis was limited to studies with confounder-adjusted analysis, increased hospital mortality remained significant among patients receiving ECMO with AKI requiring RRT with pooled OR of 3.32 (95% CI, 2.21-4.99). There was no publication bias as evaluated by the funnel plot and Egger's regression asymmetry test with p = 0.62 and p = 0.17 for the incidence of AKI and severe AKI requiring RRT, respectively.

CONCLUSION

Among patients receiving ECMO, the incidence rates of AKI and severe AKI requiring RRT are high, which has not changed over time. Patients who develop AKI requiring RRT while on ECMO carry 3.7-fold higher hospital mortality.

An audit of mortality by using ECMO specific scores and APACHE II scoring system in patients receiving extracorporeal membrane oxygenation in a tertiary intensive care unit in Hong Kong

Background

Outcomes of patients receiving extracorporeal membrane oxygenation (ECMO) therapies risk-adjusted by ECMO specific scores have rarely been reported. Our primary aim was to determine the risk adjusted outcome of these patients by the use of Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP), Survival After Veno-Arterial-ECMO (SAVE) and APACHE II scores. The differences in predicted mortality between these scoring systems were analyzed.

Methods

This is a single-center retrospective study reviewing 62 patients who received venous-venous ECMO (VV-ECMO) and venous-arterial ECMO (VA-ECMO) between 2009 and 2017 in a tertiary ICU. Demographic, clinical, laboratory, imaging data were analyzed. Primary outcome measures were the crude mortality and standardized mortality ratio (SMR), expressed as observed mortality divided by expected mortality predicted from RESP, SAVE and APACHE II scores, respectively. We also examined the difference in predicted mortality derived from RESP, SAVE, and APACHE II by using Bland Altman plots.

Results

Twenty and Forty-two patients received VV-ECMO (20 runs) and VA-ECMO (43 runs) respectively. For VV-ECMO, the mean RESP was 0.6 [standard deviation (SD) 4.86] with RESP-SMR of 1.16 [95% confidence interval (95% CI) =0.44-1.88]. For VA-ECMO, the mean SAVE score was -7.8 (SD 5.6), with SAVE-SMR of 0.69 (95% CI =0.39-0.98). In the Bland Altman plot for VA-ECMO, mean difference in predicted mortality between SAVE and APACHE II was 17.6% (95% CI: 7.6% to 27.6%, P<0.0001), with 95% limit of agreement of -30.2% to 65.5% and beta coefficient of -1.04. APACHE II predicted mortality for VA-ECMO was lower than that for SAVE until it crossed SAVE prediction at about 80% mortality. After this point, it becomes progressively higher than that for SAVE.

Conclusions

The mortality outcome of our patients on VV-ECMO and VA-ECMO compares favorably with predicted mortality based on RESP and SAVE, respectively. In our cohort of patients receiving VA-ECMO, APACHE II tends to underestimate mortality in lower risk patients, and overestimate the mortality in patients at high risk of death.

Different Clinical Course and Complications in Interagency Registry for Mechanically Assisted Circulatory Support 1 (INTERMACS) Patients Managed With or Without Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) as a bridge to left ventricular assist device (LVAD) implantation has shown promise in improving end-organ function and optimizing outcomes in some critically ill patients, but the practice remains controversial. Retrospective review of patients who received LVADs from May 2008 to September 2016 at a high-volume, tertiary care cardiovascular center was performed. Subjects were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) class 1 patients divided into ECMO bridge and non-ECMO bridge cohorts. Patient demographics, adverse events, and survival at immediate and 1 year postoperative time points were compared between groups. In total, 235 patients received a HeartMate II or HVAD during the study period. Among INTERMACS 1 patients, 18 were ECMO bridge and 17 were non-ECMO bridge. Age, gender and bridge-to-transplant proportions (50% vs. 53%) were similar between groups. The ECMO bridge group had lower hemoglobin (7.9 ± 1.1 vs. 10.2 ± 2.2; p < 0.01), platelet (101 [70] vs. 176 [115]; p < 0.05), and prealbumin levels (10.6 ± 4.3 vs. 17.3 ± 7.7; p < 0.01). Nearly half (n = 8; 44%) of the ECMO bridge patients required packed red blood cell transfusions before VAD and were more likely to be on an epinephrine drip (78% vs. 12%; p < 0.01). However, along with these adjunctive measures, the ECMO bridge did effectively improve hemodynamic profiles by the time of VAD implant resulting in lower central venous pressure (7.7 ± 2.5 vs. 10.4 ± 4.8; p < 0.01) and mean pulmonary arterial pressure (18 ± 9 vs. 32 ± 8; p < 0.01). It also allowed for restoration of end-organ function as noted by comparable creatinine (1.0 [1.2] vs. 1.4 [0.6]) and total bilirubin levels (1.6 ± 1 vs.1.5 ± 1.7) between the two groups. There was no difference in rates of adverse events. Survival at 30 days postoperative and at 1 year (77% vs. 88%; p = 0.6) was similar. This study demonstrates that ECMO bridge is a central component of a multifaceted strategy for stabilization of select patients with severe hemodynamic instability before LVAD implantation. Further studies to optimize patient selection should be further explored.

Midterm Outcomes of Bridge-to-Recovery Patients After Short-Term Mechanical Circulatory Support

BACKGROUND

The use of short-term mechanical circulatory support (ST-MCS) has increased for refractory cardiogenic shock. However, there are scant data about bridge-to-recovery patients.

METHODS

We retrospectively reviewed 502 patients with cardiogenic shock who received venoarterial extracorporeal membrane oxygenation or a temporary surgical ventricular assist device as ST-MCS between 2010 and 2016. There were 178 patients (35.5%) who survived through device explantation. Of these, 149 patients (29.7%) survived to discharge and were included for analysis. The primary outcome was midterm survival without undergoing heart replacement therapy.

RESULTS

In our bridge-to-recovery cohort, 101 patients (67.8%) were men, and the median age was 59 years (interquartile range, 51 to 67 years). Etiology of cardiogenic shock included postcardiotomy shock in 35.6% of patients (n = 53), allograft failure in 26.8% (n = 40), acute myocardial infarction (AMI) in 24.2% (n = 36), and other acute decompensated heart failure in 14.4% (n = 20). There were 24 major events (16.1%) recorded, including 21 patients who died and 3 patients who received heart replacement therapy during median follow-up of 306 days (interquartile range, 58.25 to 916.75 days). Overall freedom from event at 3 years was 74.2%. In subgroup analysis, AMI patients had a significantly worse freedom-from-event rate at 40.4% (p < 0.001). By univariate Cox analysis, AMI etiology (p = 0.003), length of ST-MCS (p = 0.06), blood urea nitrogen (p = 0.012), and left ventricular ejection fraction (p = 0.005) at discharge were predictors for adverse events.

CONCLUSIONS

The overall midterm outcome of patients explanted from ST-MCS is favorable except for AMI patients.

Selective implantation of durable left ventricular assist devices as primary therapy for refractory cardiogenic shock

OBJECTIVE

Surgical therapy for refractory primary cardiogenic shock is largely based on emergent placement of extracorporeal membrane oxygenation or short-term ventricular assist devices. We have adopted a strategy of routine implantation of durable left ventricular assist devices (LVAD) as initial therapy for refractory cardiogenic shock, in patients who are potential candidates for heart transplantation, and report our experience.

METHODS

Retrospective review of 43 consecutive patients with refractory shock caused by acute myocardial infarction (n = 21) or acute decompensated heart failure (n = 22) who were treated with primary implantation of a durable LVAD in a single institution.

RESULTS

All patients received durable LVAD (axial flow, n = 37; centrifugal, n = 4; pulsatile, n = 2), with concurrent placement of right ventricular assist device (RVAD) in 5 patients (12%). One patient had delayed RVAD implantation. Mean operative time was 362 minutes and mean cardiopulmonary bypass time was 94 minutes. Twenty patients underwent concurrent cardiac procedures. Major early adverse events included operative mortality 14% (6/43), reoperation for bleeding 7% (3/43), and stroke 4.7% (2/43). Median time on mechanical ventilation was 3.5 days, ICU stay 9 days, and hospital stay 25 days. Kaplan-Meier survival was 82.7 ± 6.0% at 6 months and 73.9 ± 8.0% at 12 months. Using competing analysis, the cumulative incidence of transplantation was 10.3 ± 5.0% at 6 months and 30.8 ± 7.9% at 1 year.

CONCLUSIONS

Our data challenge the notion that patients in refractory cardiogenic shock are best served by an initial period of stabilization with temporary devices. Primary implantation of durable LVADs in cardiogenic shock can yield good midterm outcomes and may have potential benefits.

Retrieval of Adult Patients on Extracorporeal Membrane Oxygenation by an Intensive Care Physician Model

The optimal staffing model during the inter-hospital transfer of patients on extracorporeal membrane oxygenation (ECMO) is not known. We report the complications and outcomes of patients who were commenced on ECMO at a referring hospital by intensive care physicians and compare these findings with patients who had ECMO established at an ECMO center in Australia. This was a single center, retrospective observational study based on a prospectively collected ECMO database from Melbourne, Australia. Patients with severe cardiac and/or respiratory failure failing conventional supportive treatment between 2007-2013 were placed on ECMO via a physician-led model of ECMO retrieval, including two intensivists in a four person team, using percutaneous ECMO cannulation. Patients (198) underwent ECMO over the study period, of which 31% were retrieved. Veno-venous (VV)-ECMO and veno-arterial (VA)-ECMO accounted for 27 and 73% respectively. The VA-ECMO patients had more intra-transport interventions compared with VV-ECMO transported patients, but none resulting in serious morbidity or death. There was no overall difference in survival at 6 months between retrieved and ECMO center patients: VV-ECMO (75 vs. 70%, P = 0.690) versus VA-ECMO (70 vs. 68%, P = 1.000). An intensive care physician-led team was able to safely place all critically ill patients on ECMO and retrieve them to an ECMO center. This may be an appropriate staffing model for ECMO retrieval.

Controversies and Challenges in the Management of ST-Elevation Myocardial Infarction Complicated by Cardiogenic Shock

The prognosis in ST-elevation myocardial infarction has improved with coronary care units, revascularization, and anticoagulant strategies; however, cardiogenic shock (CS) remains a highly fatal condition. Controversies remain about optimal pharmacologic therapies, revascularization strategies, the role of mechanical circulatory support (MCS), and evidence-based patient selection. The current informed consent paradigm for clinical trials creates challenges testing treatments in CS patients, who are too ill to consent and require immediate treatment. Several trials are underway comparing revascularization strategies and MCS options. Although the prognosis is grim, careful, new and existing treatments could change the course of this condition in the coming years.

Extracorporeal Life Support: Physiological Concepts and Clinical Outcomes

Extracorporeal life support (ECLS) describes a system that involves drainage from the venous circulation and return via an oxygenator into the arterial circulation (veno-arterial extracorporeal membrane oxygenation). ECLS provides effective cardiopulmonary support, but the parallel circulation has complex effects on the systemic and pulmonary circulatory physiology. An understanding of the physiological changes is fundamental to the management of ECLS. In this review, the key physiological concepts and the implications on the clinical management of ECLS are discussed. In addition, the clinical outcomes associated with ECLS in cardiogenic shock are systematically reviewed. The paucity of clinical trials on ECLS highlights the need for randomized trials to guide the selection of patients.

Moving Beyond SHOCK: New Paradigms in the Management of Acute Myocardial Infarction Complicated by Cardiogenic Shock

The current management of patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is associated with a high rate of mortality, despite widespread regional implementation of rapid transfer to percutaneous coronary intervention-capable centres for prompt infarct-related artery reperfusion. The limited clinical effectiveness of early revascularization in patients with AMI-CS might be secondary to the extent of coronary artery disease in these patients and the risk of incomplete revascularization, as well as the lower probability of achieving successful reperfusion compared with acute myocardial infarction without hemodynamic instability. Also, the severity of end-organ injury is a critical determinant of outcome. We review adjunctive therapies to early revascularization in AMI-CS, specifically with a focus on the role of short-term mechanical circulatory support. In selected patients with AMI-CS, there might be a benefit associated with early institution of mechanical circulatory support before revascularization.

Contemporary Outcomes of Venoarterial Extracorporeal Membrane Oxygenation for Refractory Cardiogenic Shock at a Large Tertiary Care Center

Refractory cardiogenic shock (RCS) is associated with significant morbidity and mortality, and current mainstays of medical therapy appear inadequate. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) represents an increasingly accepted therapy for RCS. Demographics, past medical history, preoperative characteristics, outcomes, and adverse events were collected for consecutive patients who received VA-ECMO support for RCS at our institution from March 2007 to December 2013. One hundred and seventy-nine patients with a mean age of 56.9 ± 16.1 years were included. Etiologies of RCS included postcardiotomy shock in 70 patients (39%), acute myocardial infarction in 46 patients (26%), primary graft failure in 17 patients (10%), and acute decompensated heart failure in 24 patients (13%). Mean arterial pressure before VA-ECMO support was 59.4 ± 22.8 mm Hg and 30.7% (n = 55) were undergoing active cardiopulmonary resuscitation at the time of cannulation. Overall, 38.6% of patients (n = 69) survived to discharge and 44.7% of patients (n = 80) survived to 30 days. Myocardial recovery was achieved in 79.7% of survivors (n = 55) and 39.1% were transitioned to a more durable device. Univariate analysis identified age (p = 0.002) and etiology of RCS (p = 0.041) as the most significant predictors of in-hospital mortality. Venoarterial extracorporeal membrane oxygenation for RCS appears successful as salvage therapy. Age and etiology should be considered when evaluating patients for VA-ECMO.

Using the Minimally Invasive Impella 5.0 via the Right Subclavian Artery Cutdown for Acute on Chronic Decompensated Heart Failure as a Bridge to Decision

BACKGROUND

Outcomes of traditional mechanical support paradigms (extracorporeal membrane oxygenation, intraaortic balloon pump [IABP], and permanent left ventricular assist device [LVAD]) in acute decompensated heart failure have generally been suboptimal. Novel approaches, such as minimally invasive LVAD therapy (Impella 5.0 device), promise less invasive but equivalent hemodynamic support. However, it is yet unknown whether the outcomes with such devices support widespread acceptance of this new technology. We recently started utilizing the right subclavian artery (RSA) for Impella 5.0 implantation and report our early experience and outcomes with this novel approach.

METHODS

A single-center retrospective review was performed of 24 patients with acute on chronic decompensated heart failure who received the Impella 5.0 via the RSA from June 2011 to May 2014. The device was implanted via a cutdown through an 8-mm vascular graft sewn to the RSA. The device was positioned with fluoroscopy and transesophageal echocardiography.

RESULTS

The mean age of the patients was 51.29 years, and 75% were male. At implantation, all patients were mechanically ventilated on at least 2 inotropes with persistent cardiogenic shock, and 17 (70.8%) were on IABP support. Postimplantation, 21 (87.5%) tolerated extubation, and all 17 of the patients with IABPs tolerated discontinuation of IABP support. The reduction in the Model for End-Stage Liver Disease score preimplantation vs postimplantation was statistically significant (21.17 vs 14.88, P=0.0014), suggesting improvement in end organ function. A significant decrease was also seen in creatinine levels before and after implantation (2.17 mg/dL vs 1.50 mg/dL, P=0.0043). The endpoint of support included recovery in 6 patients (25.0%), permanent LVAD in 9 (37.5%), and heart transplantation in 2 (8.3%). Death occurred in 7 patients (29.2%) as a result of multisystem organ failure, infection, or patient withdrawal of care.

CONCLUSION

Minimally invasive LVAD therapy using the Impella 5.0 via the RSA cutdown is an attractive option in acute on chronic decompensated heart failure. Improvement in end organ function allows for transition to recovery or to advanced surgical therapies such as permanent LVAD and heart transplantation. Significant advantages to this approach include improved left ventricular unloading, lower anticoagulation need, and the potential for ambulation and physical therapy.

Clinical Features and outcomes in adults with cardiogenic shock supported by extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is an increasingly used supportive measure for patients with refractory cardiogenic shock (CS). Despite its increasing use, there remain minimal data regarding which patients with refractory CS are most likely to benefit from ECMO. We retrospectively studied all patients (n = 123) who underwent initiation of ECMO for CS from February 2009 to September 2014 at a single center. Baseline patient characteristics, including demographics, co-morbid illness, cause of CS, available laboratory values, and patient outcomes were analyzed. Overall, 69 patients (56%) were weaned from ECMO, with 48 patients (39%) surviving to discharge. Survivors were younger (50 vs 60 years; p ≤0.0001), had a lower rate of previous smoking (27 vs 56%; p = 0.01) and chronic kidney disease (2% vs 13%; p = 0.03), and had lower lactate measured soon after ECMO initiation (3.1 vs 10.2 mmol/l; p = 0.01). Patients with pulmonary embolism (odds ratio 8.0, 95% confidence interval 2.00 to 31.99; p = 0.01) and acute cardiomyopathy (odds ratio 7.5, 95% confidence interval 1.69 to 33.27; p = 0.01) had a higher rate of survival than acute myocardial infarction, chronic cardiomyopathy, and miscellaneous etiologies compared to postcardiotomy CS as a referent. In conclusion, survival after ECMO initiation differs based on underlying cause of CS. Survival may be lower in older patients and those with early evidence of persistent hypoperfusion after initiation of ECMO for CS.

Acute Myocardial Infarction Complicated by Cardiogenic Shock: An Algorithm-Based Extracorporeal Membrane Oxygenation Program Can Improve Clinical Outcomes

Extracorporeal membrane oxygenation (ECMO) in our institution resulted in near total mortality prior to the establishment of an algorithm-based program in July 2010. We hypothesized that an algorithm-based ECMO program improves the outcome of patients with acute myocardial infarction complicated with cardiogenic shock. Between March 2003 and July 2013, 29 patients underwent emergent catheterization for acute myocardial infarction due to left main or proximal left anterior descending artery occlusion complicated with cardiogenic shock (defined as systolic blood pressure <90 mm Hg despite multiple inotropes, with or without intra-aortic balloon pump, lactic acidosis). Of 29 patients, 15 patients were treated before July 2010 (Group 1, old program), and 14 patients were treated after July 2010 (Group 2, new program). There were no significant differences in the baseline characteristics, including age, sex, coronary risk factors, and left ventricular ejection fraction between the two groups. Cardiopulmonary resuscitation prior to ECMO was performed in two cases (13%) in Group 1 and four cases (29%) in Group 2. ECMO support was performed in one case (6.7%) in Group 1 and six cases (43%) in Group 2. The 30-day survival of Group 1 versus Group 2 was 40 versus 79% (P = 0.03), and 1-year survival rate was 20 versus 56% (P = 0.01). The survival rate for patients who underwent ECMO was 0% in Group 1 versus 83% in Group 2 (P = 0.09). In Group 2, the mean duration on ECMO was 9.8 ± 5.9 days. Of the six patients who required ECMO in Group 2, 100% were successfully weaned off ECMO or were bridged to ventricular assist device implantation. Initiation of an algorithm-based ECMO program improved the outcomes in patients with acute myocardial infarction complicated by cardiogenic shock.

Use of Extracorporeal Membrane Oxygenation to Rescue Patients With Refractory Ventricular Arrhythmia in Acute Myocardial Infarction

Refractory ventricular arrhythmia is a serious problem in acute myocardial infarction (AMI), with an extremely high mortality rate and limited effective treatment. Extracorporeal membrane oxygenation (ECMO) is useful to rescue patients with cardiopulmonary collapse. However, little is known about whether ECMO is a potential rescue technique for patients with refractory ventricular arrhythmia in AMI.We retrospectively analyzed prospectively collected data on patients with AMI and refractory ventricular arrhythmia who underwent ECMO as rescue therapy and the bridge to revascularization from February 2001 to January 2013. Primary endpoint was mortality on index admission, and secondary endpoint was mortality on index admission or advanced brain damage at discharge.A total of 69 (62 men) patients were enrolled in this study. During the index admission, 39 patients (56.5%) met primary endpoint, and 45 patients (65.2%) met secondary endpoint, respectively. In multivariate Cox regression analysis, both the presence of profound anoxic encephalopathy and acute renal failure requiring dialysis were significant predictive factors for both primary and secondary endpoints.ECMO is a feasible rescue therapy and bridge to revascularization in patients with refractory ventricular arrhythmia in acute myocardial infarction. The presence of profound anoxic encephalopathy and acute renal failure requiring dialysis were significant prognostic factors.

Percutaneous Mechanical Support in Cardiogenic Shock: A Review

Cardiogenic shock (CS) is a life-threatening condition associated with significant morbidity and mortality. Pharmacological therapy is often the first line of treatment but mechanical support can provide substantial hemodynamic improvement in refractory CS. Percutaneous mechanical support devices are placed in a minimally invasive manner and provide life-saving assistance to the failing myocardium. We review the percutaneous devices currently available, the evidence behind their use, and the new advances in percutaneous technology being evaluated for the treatment of CS.

Veno-arterial extracorporeal membrane oxygenation for adult cardiovascular failure

PURPOSE OF REVIEW

To examine the utility and technical challenges of applying veno-arterial extracorporeal membrane oxygenation for acute cardiovascular failure in adults with acute and chronic causes of heart failure.

RECENT FINDINGS

The role of mechanical circulatory support in acute cardiovascular continues to evolve as technology and clinical experience develop. There is increasing interest in the role of veno-arterial extracorporeal membrane oxygenation as a bridging therapy and as an adjunct to conventional cardiopulmonary resuscitation.

SUMMARY

Veno-arterial extracorporeal membrane oxygenation is an expensive, complex, resource intensive support. It is essential that its future use be guided by evidence obtained from centres that have demonstrated timely, safe support.

Venoarterial Extracorporeal Membrane Oxygenation in Adults With Cardiac Arrest

Cardiac arrest (CA) is a major cause of morbidity and mortality worldwide. Despite the use of conventional cardiopulmonary resuscitation (CPR), rates of return of spontaneous circulation and survival with minimal neurologic impairment remain low. Utilization of venoarterial extracorporeal membrane oxygenation (ECMO) for CA in adults is steadily increasing. Propensity-matched cohort studies have reported outcomes associated with ECMO use to be superior to that of conventional CPR alone in in-hospital patients with CA. In this review, we discuss the mechanism, indications, complications, and evidence for ECMO in CA in adults.

[Use of ECMO in adult patients with cardiogenic shock: a position paper of the Austrian Society of Cardiology]

The use of ECMO to stabilize critically ill patients with severely depressed cardiac function and hemodynamics increased in the last years due to broader availability, better performance and easier implantation of the devices. The present guidelines of the Austrian Society of Cardiology focus on the use of ECMO in adult non-operated patients with cardiac diseases. Not only indications and contraindications are highlighted, but also the equally important issues of monitoring, complication management, measures during implantation and operation, and weaning of the devices are treated in detail. Thereby the present guidelines aim to optimize the use of ECMO in the individual centers, and aim to help current non-ECMO centers in developing a local ECMO-program or to contact ECMO-centers for discussion of individual patients.

Venoarterial extracorporeal membrane oxygenation for cardiogenic shock and cardiac arrest: a meta-analysis

OBJECTIVE

To evaluate the effect of extracorporeal membrane oxygenation (ECMO) on survival and complication rates in adults with refractory cardiogenic shock or cardiac arrest.

DESIGN

Meta-analysis.

SETTING

University hospitals.

PARTICIPANTS

One thousand one hundred ninety-nine patients from 22 observational studies.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Observational studies published from the year 2000 onwards, examining at least 10 adult patients who received ECMO for refractory cardiogenic shock or cardiac arrest were included. Pooled estimates with 95% confidence intervals were calculated based on the Freeman-Tukey double-arcsine transformation and DerSimonian-Laird random-effect model. Survival to discharge was 40.2% (95% confidence intervals [CI], 33.9-46.7), while survival at 3, 6, and 12 months was 55.9% (95% CI, 41.5-69.8), 47.6% (95% CI, 25.4-70.2), and 54.4% (95% CI, 36.6-71.7), respectively. Survival up to 30 days was higher in cardiogenic shock patients (52.5%, 95% CI, 43.7%-61.2%) compared to cardiac arrest (36.2%, 95% CI, 23.1%-50.4%). Concurrently, complication rates were particularly substantial for neurologic deficits (13.3%, 95% CI, 8.3-19.3), infection (25.1%, 95%CI, 15.9-35.5), and renal impairment (47.4%, 95% CI, 30.2-64.9). Significant heterogeneity was detected, although its levels were similar to previous meta-analyses that only examined short-term survival to discharge.

CONCLUSIONS

Venoarterial ECMO can improve short-term survival in adults with refractory cardiogenic shock or cardiac arrest. It also may provide favorable long-term survival at up to 3 years postdischarge. However, ECMO also is associated with significant complication rates, which must be incorporated into the risk-benefit analysis when considering treatment. These findings require confirmation by large, adequately controlled and standardized trials with long-term follow-up.

Important role of mechanical circulatory support in acute myocardial infarction complicated by cardiogenic shock

OBJECTIVES

Acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) remains associated with significant mortality despite the widespread application of early revascularization strategies. Recent evidence suggests that the use of intra-aortic balloon pump (IABP) counterpulsation does not improve mortality in this cohort of patients. We summarize our experience with mechanical circulatory support (MCS) therapy for AMI/CS.

METHODS

This is a retrospective review of 61 patients who received MCS therapy for AMI/CS at our institution between March 2007 and March 2013.

RESULTS

Mean age was 60.2 ± 10.3 years; mean ejection fraction was 24 ± 15% and 29% of patients were receiving active cardiopulmonary resuscitation at the time of support initiation. Prior to the initiation of MCS, 70.5% of patients had an IABP. Mean arterial pressure improved significantly with MCS (63 mmHg prior to MCS, 82 mmHg after MCS, P ≤ 0.01). Mean length of support was 9.5 ± 11.0 days, and overall survival to 30 days was 59.0%. Among 30-day survivors, 44.4% required device exchange to a durable MCS device. Ultimately, only 31% (52.8% of patients who survived to 30 days) achieved myocardial recovery.

CONCLUSIONS

Short-term MCS therapy with subsequent aggressive use of durable MCS device may improve the unacceptably high mortality rate in AMI/CS. Rigorous prospective studies of MCS therapy in AMI/CS are warranted.

Extracorporeal life support in critically ill adults

Extracorporeal life support (ECLS) has become increasingly popular as a salvage strategy for critically ill adults. Major advances in technology and the severe acute respiratory distress syndrome that characterized the 2009 influenza A(H1N1) pandemic have stimulated renewed interest in the use of venovenous extracorporeal membrane oxygenation (ECMO) and extracorporeal carbon dioxide removal to support the respiratory system. Theoretical advantages of ECLS for respiratory failure include the ability to rest the lungs by avoiding injurious mechanical ventilator settings and the potential to facilitate early mobilization, which may be advantageous for bridging to recovery or to lung transplantation. The use of venoarterial ECMO has been expanded and applied to critically ill adults with hemodynamic compromise from a variety of etiologies, beyond postcardiotomy failure. Although technology and general care of the ECLS patient have evolved, ECLS is not without potentially serious complications and remains unproven as a treatment modality. The therapy is now being tested in clinical trials, although numerous questions remain about the application of ECLS and its impact on outcomes in critically ill adults.