Mechanical Left Ventricular Unloading in Patients Undergoing Venoarterial Extracorporeal Membrane Oxygenation

Advanced Critical Care Techniques in the Field

Critical care principles and techniques continue to hold promise for improving patient outcomes in time-dependent diseases encountered by emergency medical services such as cardiac arrest, acute ischemic stroke, and hemorrhagic shock. In this review, the authors discuss several current and evolving advanced critical care modalities, including extracorporeal cardiopulmonary resuscitation, resuscitative endovascular occlusion of the aorta, prehospital thrombolytics for acute ischemic stroke, and low-titer group O whole blood for trauma patients. Two important critical care monitoring technologies-capnography and ultrasound-are also briefly discussed.

ECPELLA: Beyond a Left Ventricular Venting Strategy When to Unload the Left Ventricle and How to Decide

Left ventricular (LV) unloading has been shown to improve survival for patients requiring veno-arterial extracorporeal membrane oxygenation (VA ECMO) support for cardiogenic shock. A mortality benefit has been shown for ECMO and concomitant placement of a transcatheter unloading LV pump such as an Impella device (colloquially referred to as ECPELLA or ECMELLA) for patients resuscitated with VA ECMO after a short period of cardiac arrest. Despite the described benefit of LV unloading with VA ECMO for cardiopulmonary resuscitation, it remains unclear as to what criteria should be used and what other diagnostic and therapeutic adjuncts may be useful. We describe here the successful utilization of concomitant VA ECMO and Impella in a 43 year old male with acute heart failure and cardiac arrest. Distinguishing itself from the currently reported methods, our methodology incorporates transesophageal echocardiography (TEE) in the emergency department for rapid decision-making in addition to an automatic chest compression device, the Lund University Cardiac Assist System (LUCAS) device (Stryker, Portage, MI) as a bridge to LV unloading in a hybrid operating suite.

Transcatheter Axial Pump Use in Pediatric Patients on Veno-Arterial Extracorporeal Membrane Oxygenation: An ACTION Collaborative Experience

We report the largest pediatric multicenter experience with Impella pump use and peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support. Utilizing the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) collaborative database, we conducted a retrospective, multicenter study of all patients with cardiogenic shock requiring VA-ECMO support with subsequent Impella implant between October 2014 and December 2021. The primary outcome was defined as death while on Impella support. Secondary outcomes were recovery, transplantation, and transition to durable ventricular assist device (VAD) at the time of Impella explantation. Adverse events were defined according to the ACTION registry criteria. Twenty subjects were supported with Impella; Impella 2.5 (n = 3), CP (n = 12), 5.0/5.5 (n = 5). The median Interquartile range (IQR) age, weight, and body surface area at implantation were 15.6 years (IQR = 13.9-17.2), 65.7 kg (IQR = 53.1-80.7), and 1.74 m2 (IQR = 1.58-1.98). Primary cardiac diagnoses were dilated cardiomyopathy/myocarditis in nine (45%), congenital heart disease in four (20%), graft failure/rejection in four (20%), and three (15%) others. Most common adverse events included hemolysis (50%) and bleeding (20%). There were two deaths (10%) in the cohort. Nine patients (45%) were explanted for recovery, eight (40%) were transitioned to a durable VAD, and one (5%) underwent heart transplantation. Impella percutaneous pump support should be considered in the older pediatric population supported with peripheral VA-ECMO, as a means of left heart decompression, and a strategy to come off ECMO to achieve endpoints of myocardial recovery, transition to a durable VAD, or transplantation.

Hemodynamic management of cardiogenic shock in the intensive care unit

Hemodynamic derangements are defining features of cardiogenic shock. Randomized clinical trials have examined the efficacy of various therapeutic interventions, from percutaneous coronary intervention to inotropes and mechanical circulatory support (MCS). However, hemodynamic management in cardiogenic shock has not been well-studied. This State-of-the-Art review will provide a framework for hemodynamic management in cardiogenic shock, including a description of the 4 therapeutic phases from initial 'Rescue' to 'Optimization', 'Stabilization' and 'de-Escalation or Exit therapy' (R-O-S-E), phenotyping and phenotype-guided tailoring of pharmacological and MCS support, to achieve hemodynamic and therapeutic goals. Finally, the premises that form the basis for clinical management and the hypotheses for randomized controlled trials will be discussed, with a view to the future direction of cardiogenic shock.

Impact of Left Ventricular Unloading on Outcome of Heart Transplant Bridging With Extracorporeal Membrane Oxygenation Support in New Allocation Policy

BACKGROUND

The new heart allocation policy places veno-arterial extracorporeal membrane oxygenation (VA-ECMO)-supported heart transplant (HT) candidates at the highest priority status. Despite increasing evidence supporting left ventricular (LV) unloading during VA-ECMO, the effect of LV unloading on transplant outcomes following bridging to HT with VA-ECMO remains unknown.

METHODS AND RESULTS

From October 18, 2018 to March 21, 2023, 624 patients on VA-ECMO at the time of HT were identified in the United Network for Organ Sharing database and were divided into 2 groups: VA-ECMO alone (N=384) versus VA-ECMO with LV unloading (N=240). Subanalysis was performed in the LV unloading group: Impella (N=106) versus intra-aortic balloon pump (N=134). Recipient age was younger in the VA-ECMO alone group (48 versus 53 years, P=0.018), as was donor age (VA-ECMO alone, 29 years versus LV unloading, 32 years, P=0.041). One-year survival was comparable between groups (VA-ECMO alone, 88.0±1.8% versus LV unloading, 90.4±2.1%; P=0.92). Multivariable Cox hazard model showed LV unloading was not associated with posttransplant mortality after HT (hazard ratio, 0.92; P=0.70). Different LV unloading methods had similar 1-year survival (intra-aortic balloon pump, 89.2±3.0% versus Impella, 92.4±2.8%; P=0.65). Posttransplant survival was comparable between different Impella versions (Impella 2.5, versus Impella CP, versus Impella 5.0, versus Impella 5.5).

CONCLUSIONS

Under the current allocation policy, LV unloading did not impact waitlist outcome and posttransplant survival in patients bridged to HT with VA-ECMO, nor did mode of LV unloading. This highlights the importance of a tailored approach in HT candidates on VA-ECMO, where routine LV unloading may not be universally necessary.

Left Ventricular Unloading in Extracorporeal Membrane Oxygenation: A Clinical Perspective Derived from Basic Cardiovascular Physiology

PURPOSE OF REVIEW

To present an abridged overview of the literature and pathophysiological background of adjunct interventional left ventricular unloading strategies during veno-arterial extracorporeal membrane oxygenation (V-A ECMO). From a clinical perspective, the mechanistic complexity of such combined mechanical circulatory support often requires in-depth physiological reasoning at the bedside, which remains a cornerstone of daily practice for optimal patient-specific V-A ECMO care.

RECENT FINDINGS

Recent conventional clinical trials have not convincingly shown the superiority of V-A ECMO in acute myocardial infarction complicated by cardiogenic shock as compared with medical therapy alone. Though, it has repeatedly been reported that the addition of interventional left ventricular unloading to V-A ECMO may improve clinical outcome. Novel approaches such as registry-based adaptive platform trials and computational physiological modeling are now introduced to inform clinicians by aiming to better account for patient-specific variation and complexity inherent to V-A ECMO and have raised a widespread interest. To provide modern high-quality V-A ECMO care, it remains essential to understand the patient's pathophysiology and the intricate interaction of an individual patient with extracorporeal circulatory support devices. Innovative clinical trial design and computational modeling approaches carry great potential towards advanced clinical decision support in ECMO and related critical care.

Innovating to resolve the pressure-oxygenation-paradox created by VA-ECMO could improve outcomes for acute myocardial infarction and cardiogenic shock

VA-ECMO use is growing exponentially. Recent data shows no clinical benefit with routine use of VA-ECMO in acute myocardial infarction and shock, however clinical experience with ECMO is growing. Two key variables that may impact outcomes with ECMO in acute myocardial infarction and shock include it's effect on systemic pressure and oxygenation. We define the pressure-oxygenaton paradox of ECMO as a potential new avenue for therapeutic discovery.

The physiology of venoarterial extracorporeal membrane oxygenation - A comprehensive clinical perspective

Venoarterial extracorporeal membrane oxygenation (VA ECMO) has become a standard of care for severe cardiogenic shock, refractory cardiac arrest and related impending multiorgan failure. The widespread clinical use of this complex temporary circulatory support modality is still contrasted by a lack of formal scientific evidence in the current literature. This might at least in part be attributable to VA ECMO related complications, which may significantly impact on clinical outcome. In order to limit adverse effects of VA ECMO as much as possible an indepth understanding of the complex physiology during extracorporeally supported cardiogenic shock states is critically important. This review covers all relevant physiological aspects of VA ECMO interacting with the human body in detail. This, to provide a solid basis for health care professionals involved in the daily management of patients supported with VA ECMO and suffering from cardiogenic shock or cardiac arrest and impending multiorgan failure for the best possible care.

Contemporary Outcomes of Children With Acute Fulminant Myocarditis Supported With Peripheral Extracorporeal Membrane Oxygenation

Despite extracorporeal membrane oxygenation (ECMO) utilization in nearly 20% of cases, there are limited data in children with acute fulminant myocarditis (AFM) requiring ECMO. Herein we identify risk factors for death or heart transplant (HT) in children with AFM supported with ECMO, describe our experience with left atrial (LA) decompression, and depict long-term outcomes of survivors. We performed a retrospective cohort of patients <18 years with AFM (≤14 days of symptoms, rapid cardiogenic shock, and normal left ventricular [LV] size on presentation) supported with ECMO admitted to a single intensive care unit from 1997 to 2021. Among 28 patients (median age 9 years), 21 (75%) survived to discharge without HT. Patients were supported on ECMO for a median of 6 days. Three patients were bridged to HT with durable ventricular assist devices (VAD). Four patients died, two of whom were supported with VAD. At presentation, seven (25%) patients had high grade or complete atrioventricular block and eight (29%) had ventricular tachycardia. Before ECMO cannulation, 21 (75%) patients received CPR. The death/HT group had higher peak troponin levels (12.5 vs . 1.0 ng/ml, p = 0.02) and initial mean LA or pulmonary capillary wedge pressure (27 vs . 18 mm Hg, p = 0.03). Left atrial decompression was performed in 22 patients (79%). Twenty-two (79%) had acute myocarditis on endomyocardial biopsy. Among transplant-free survivors, 18 (86%) had normalization in LV function (median 7 days); the remaining three patients had persistent mild LV dysfunction at last follow-up (median 842 days). Transplant-free survival of pediatric patients with AFM supported on ECMO was 75% and associated with lower initial LA pressure and lower peak troponin. Recovery in ventricular function among survivors was rapid and durable.

Outcomes of Veno-Arterial Extracorporeal Membrane Oxygenation With Percutaneous Left Ventricular Unloading in Fulminant Myocarditis

Fulminant myocarditis requiring peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has a high mortality rate. We investigated clinical outcomes of combined use of VA-ECMO and percutaneous left ventricular assist device (VAD) (Impella) for fulminant myocarditis in 104 consecutive patients enrolled in the Japan Registry for Percutaneous VAD (J-pVAD) between October 2017 and January 2020. Patients were followed until hospital discharge and predictors of survival were analyzed with a Cox proportional hazards model. The median support duration of combined use of VA-ECMO and Impella (ECMO/Impella) was 6 days, and the median left ventricular ejection fraction improved from 15% to 52% during support ( p < 0.0001). Overall, 66 patients (63%) survived to discharge. Multivariate analysis revealed ECMO/Impella support at a transplant center as an independent predictor of survival ( p = 0.0231). Patients treated at transplant centers had better 60 days survival rates when compared to nontransplant centers (83% vs. 55%, p = 0.005). However, baseline characteristics and treatment strategies differed between the two groups. This real-world national registry database suggested the difference in survival after ECMO/Impella support for fulminant myocarditis between transplant and nontransplant centers, which may indicate hospital variations regarding patient management, although further controlled studies are needed.

Left ventricular unloading in patients supported with veno-arterial extra corporeal membrane oxygenation; an international EuroELSO survey

INTRODUCTION

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) improves end-organ perfusion in cardiogenic shock but may increase afterload, which can limit cardiac recovery. Left ventricular (LV) unloading strategies may aid cardiac recovery and prevent complications of increased afterload. However, there is no consensus on when and which unloading strategy should be used.

METHODS

An online survey was distributed worldwide via the EuroELSO newsletter mailing list to describe contemporary international practice and evaluate heterogeneity in strategies for LV unloading.

RESULTS

Of 192 respondents from 43 countries, 53% routinely use mechanical LV unloading, to promote ventricular recovery and/or to prevent complications. Of those that do not routinely unload, 65% cited risk of complications as the reason. The most common indications for unplanned unloading were reduced arterial line pulsatility (68%), pulmonary edema (64%) and LV dilatation (50%). An intra-aortic balloon pump was the most frequently used device for unloading followed by percutaneous left ventricular assist devices. Echocardiography was the most frequently used method to monitor the response to unloading.

CONCLUSIONS

Significant variation exists with respect to international practice of ventricular unloading. Further research is required that compares the efficacy of different unloading strategies and a randomized comparison of routine mechanical unloading versus unplanned unloading.

Management of cardiogenic shock: a narrative review

Cardiogenic shock (CS) is characterized by low cardiac output and sustained tissue hypoperfusion that may result in end-organ dysfunction and death. CS is associated with high short-term mortality, and its management remains challenging despite recent advances in therapeutic options. Timely diagnosis and multidisciplinary team-based management have demonstrated favourable effects on outcomes. We aimed to review evidence-based practices for managing patients with ischemic and non-ischemic CS, detailing the multi-organ supports needed in this critically ill patient population.

Temporary extracorporeal life support: single-centre experience with a new concept

OBJECTIVES

The combination of veno-arterial extracorporeal membrane oxygenation with a micro-axial flow pump (ECMELLA) is increasingly used for cardiogenic shock (CS) therapy. We report our experience with a novel single-artery access ECMELLA setup with either femoral (2.0) or jugular venous cannulation (2.1), respectively.

METHODS

Data from 67 consecutive CS patients treated with ECMELLA 2.0 (n = 56) and 2.1 (n = 11) from December 2020 and December 2022 in a tertiary cardiac center were retrospectively analyzed.

RESULTS

The mean age was 60.7 ± 11 years, 56 patients (84%) were male. CS aetiology was acute on chronic heart failure (n = 35, 52%), myocardial infarction (n = 13, 19.5%), postcardiotomy syndrome (n = 16, 24%) and myocarditis (n = 3, 4.5%). Preoperatively 31 patients (46%) were resuscitated, 53 (79%) were on a ventilator and 60 (90%) were on inotropic support. The median vasoactive inotropic score was 32, and the mean arterial lactate was 8.1 mmol/l. In 39 patients (58%), veno-arterial extracorporeal membrane oxygenation was explanted after a median ECMELLA support of 4 days. Myocardial recovery was achieved in 18 patients (27%), transition to a durable left ventricular assist device in 16 (24%). Thirty-three patients (n = 33; 49%) died on support (25 on ECMELLA and 8 on Impella after de-escalation), 9 (13%) of whom were palliated. Axillary access site bleeding occurred in 9 patients (13.5%), upper limb ischaemia requiring surgical revision in 3 (4.5%). Axillary site infection occurred in 6 cases (9%), and perioperative stroke in 10 (15%; 6 hemorrhagic, 4 thromboembolic).

CONCLUSIONS

ECMELLA 2.0/2.1 is a feasible and effective therapy for severe CS. The single-artery cannulation technique is associated with a relatively low rate of access-related complications.

Impella Versus Intra-Aortic Balloon Pump in Patients With Cardiogenic Shock Treated With Venoarterial Extracorporeal Membrane Oxygenation: An Observational Study

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used for patients with cardiogenic shock. Although Impella or intra-aortic balloon pump (IABP) is frequently used for left ventricular unloading (LVU) during VA-ECMO treatment, there are limited data on comparative outcomes. We compared outcomes of Impella and IABP for LVU during VA-ECMO.

METHODS AND RESULTS

Using the Nationwide Readmissions Database between 2016 and 2020, we analyzed outcomes in 3 groups of patients with cardiogenic shock requiring VA-ECMO based on LVU strategies: extracorporeal membrane oxygenation (ECMO) only, ECMO with IABP, and ECMO with Impella. Of 15 980 patients on VA-ECMO, IABP and Impella were used in 19.4% and 16.4%, respectively. The proportion of patients receiving Impella significantly increased from 2016 to 2020 (6.5% versus 25.8%; P-trend<0.001). In-hospital mortality was higher with ECMO with Impella (54.8%) compared with ECMO only (50.4%) and ECMO with IABP (48.4%). After adjustment, ECMO with IABP versus ECMO only was associated with lower in-hospital mortality (adjusted odds ratio [aOR], 0.83; P=0.02). ECMO with Impella versus ECMO only had similar in-hospital mortality (aOR, 1.09; P=0.695) but was associated with more bleeding (aOR, 1.21; P=0.007) and more acute kidney injury requiring hemodialysis (aOR, 1.42; P<0.001). ECMO with Impella versus ECMO with IABP was associated with greater risk of acute kidney injury requiring hemodialysis (aOR, 1.49; P=0.002), higher in-hospital mortality (aOR, 1.32; P=0.001), and higher 40-day mortality (hazard ratio, 1.25; P<0.001).

CONCLUSIONS

In patients with cardiogenic shock on VA-ECMO, LVU with Impella, particularly with 2.5/CP, was not associated with improved survival at 40 days but was associated with increased adverse events compared with IABP. More data are needed to assess Impella platform-specific comparative outcomes of LVU.

Timing of Initiation of Extracorporeal Membrane Oxygenation Support and Outcomes Among Patients With Cardiogenic Shock

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (ECMO) provides full hemodynamic support for patients with cardiogenic shock, but optimal timing of ECMO initiation remains uncertain. We sought to determine whether earlier initiation of ECMO is associated with improved survival in cardiogenic shock.

METHODS AND RESULTS

We analyzed adult patients with cardiogenic shock who received venoarterial ECMO from the international Extracorporeal Life Support Organization (ELSO) registry from 2009 to 2019, excluding those cannulated following an operation. Multivariable logistic regression evaluated the association between time from admission to ECMO initiation and in-hospital death. Among 8619 patients (median, 56.7 [range, 44.8-65.6] years; 33.5% women), the median duration from admission to ECMO initiation was 14 (5-32) hours. Patients who had ECMO initiated within 24 hours (n=5882 [68.2%]) differed from those who had ECMO initiated after 24 hours, with younger age, more preceding cardiac arrest, and worse acidosis. After multivariable adjustment, patients with ECMO initiated >24 hours after admission had higher risk of in-hospital death (adjusted odds ratio, 1.20 [95% CI, 1.06-1.36]; P=0.004). Each 12-hour increase in the time from admission to ECMO initiation was incrementally associated with higher adjusted in-hospital mortality rate (adjusted odds ratio, 1.06 [95% CI, 1.03-1.10]; P<0.001). The association between longer time to ECMO and worse outcomes appeared stronger in patients with lower shock severity.

CONCLUSIONS

Longer delays from admission to ECMO initiation were associated with higher a mortality rate in a large-scale, international registry. Our analysis supports optimization of door-to-support time and the avoidance of inappropriately delayed ECMO initiation.

Intra-aortic balloon pump in patients with extracorporeal cardiopulmonary resuscitation after cardiac arrest caused by acute coronary syndrome

BACKGROUND

This study evaluated the association between intra-aortic balloon pump (IABP) use in patients with out-of-hospital cardiac arrest (OHCA) caused by acute coronary syndrome (ACS) who received extracorporeal cardiopulmonary resuscitation (ECPR) and 30-day outcomes.

METHODS

This study was a secondary analysis of data from the SAVE-J II study, a retrospective, multicenter registry study involving 36 participating institutions in Japan. Patients with cardiac arrest caused by ACS who received ECPR were divided into two groups depending on whether or not they received IABP. The primary outcome was 30-day survival. Subgroup analysis was performed to detect what type of patients were mostly associated with improved outcomes.

RESULTS

Of 2,157 patients registered in the SAVE-J II study, 877 patients were enrolled in this study, 702 patients in the IABP group and 175 patients in the non-IABP group. Multivariable logistic regression analysis did not reveal a significant difference in 30-day survival (OR 1.37, 95% CI 0.91-2.07, p = 0.13). In the subgroup analysis, 30-day survival among patients without percutaneous coronary intervention (PCI) and stenosis of multiple coronary vessels were associated with IABP use.

CONCLUSIONS

IABP use in patients with OHCA with ACS who received ECPR is not associated with 30-day survival. The use of IABP in patients who did not have PCI and have multiple coronary vessel stenoses warrants further study.

Differential effect of left ventricular unloading according to the aetiology of cardiogenic shock

AIMS

Evidence for the effectiveness of left ventricular (LV) unloading in patients who received venoaterial extracorporeal membrane oxygenation (VA-ECMO) for acute myocardial infarction (AMI) or non-AMI induced cardiogenic shock (CS) is limited. The aim of the present study was to compare the effect of LV unloading in AMI-induced and non-AMI-induced CS.

METHODS AND RESULTS

This is a single-centre retrospective observational study of patients with CS undergoing VA-ECMO from January 2011 to March 2019. Patients were classified as AMI-induced and non-AMI-induced CS. The association of LV unloading with 90-day mortality in both groups was analysed using Cox proportional hazard regression analysis.

RESULTS

Of the 128 CS patients, 71 (55.5%) patients received VA-ECMO due to AMI-induced CS, and the remaining 57 (44.5%) received VA-ECMO due to non-AMI-induced CS. The modality of LV unloading was predominantly with IABP (94.5%). In the AMI-induced CS group, LV unloading did not reduce 90-day mortality (adjusted hazard ratio 1.96, 95% confidence interval 0.90-4.27, P = 0.089). However, in the non-AMI-induced CS group, LV unloading combined with VA-ECMO significantly reduced 90-day mortality (adjusted hazard ratio 0.37, 95% confidence interval 0.14-0.96, P = 0.041; P for interaction = 0.029) as compared with those who received VA-ECMO alone.

CONCLUSIONS

LV unloading with VA-ECMO may reduce 90-day mortality compared with VA-ECMO alone in patients with non-AMI-induced CS, but not in AMI-induced CS.

Use of Extracorporeal Membrane Oxygenation for Primary Graft Dysfunction After Cardiac Transplantation: Results of an A Priori Ventless Approach

Primary graft dysfunction (PGD) after cardiac transplantation is a devastating complication with increasing frequency lately in the setting of donation after circulatory death (DCD). Severe PGD is commonly treated with extracorporeal membrane oxygenation (ECMO) using central or peripheral cannulation. We retrospectively reviewed the outcomes of PGD after cardiac transplantation requiring ECMO support at our center from 2015 to 2020, focused on our now preferential approach using peripheral cannulation without a priori venting. During the study period, 255 patients underwent heart transplantation at our center and 26 (10.2%) of them required ECMO for PGD. Of 24 patients cannulated peripherally 19 (79%) were alive at 30 days and 17 (71%) 1 year after transplant; two additional patients underwent central ECMO cannulation due to unfavorable size of femoral vessels and concern for limb ischemia. Successful decannulation with full graft function recovery occurred in 22 of 24 (92%) patients cannulated peripherally. Six of them had an indwelling intra-aortic balloon pump placed before the transplantation. None of the other 18 patients received a ventricular vent. In conclusion, the use of an a priori peripheral and ventless ECMO approach in patients with PGD after heart transplant is an effective strategy associated with high rates of graft recovery and survival.

Adult Highlights From the Extracorporeal Life Support Organization Registry: 2017-2022

The Extracorporeal Life Support Organization (ELSO) registry captures clinical data and outcomes on patients receiving extracorporeal membrane oxygenation (ECMO) support across the globe at participating centers. It provides a very unique opportunity to benchmark outcomes and analyze the clinical course to help identify ways of improving patient outcomes. In this review, we summarize select adult ECMO articles published using the ELSO registry over the past 5 years. These articles highlight innovative utilization of the registry data in generating hypotheses for future clinical trials. Members of the ELSO Scientific Oversight Committee can be found here: https://www.elso.org/registry/socmembers.aspx .

Age and associated outcomes among patients receiving venoarterial extracorporeal membrane oxygenation-analysis of the Extracorporeal Life Support Organization registry

PURPOSE

Venoarterial extracorporeal membrane oxygenation (V-A ECMO) can be used to support severely ill patients with cardiogenic shock. While age is commonly used in patient selection, little is known regarding its association with outcomes in this population. We sought to evaluate the association between increasing age and outcomes following V-A ECMO.

METHODS

We used individual-level patient data from 440 centers in the international Extracorporeal Life Support Organization registry. We included all adult patients receiving V-A ECMO from 2017 to 2019. The primary outcome was hospital mortality. Secondary outcomes included a composite of complications following initiation of V-A ECMO. We conducted Bayesian analyses of the relationship between increasing age and outcomes of interest.

RESULTS

We included 15,172 patients receiving V-A ECMO. Of these, 8172 (53.9%) died in hospital. For the analysis conducted using weakly informed priors, and as compared to the reference category of age 18-29, the age bracket of 30-39 (odds ratio [OR] 0.94, 95% credible interval [CrI] 0.79-1.10) was not associated with hospital mortality, but age brackets 40-49 (odds ratio [OR] 1.26, 95% CrI: 1.08-1.47), 50-59 (OR 1.78, 95% CrI: 1.55-2.06), 60-69 (OR 2.24, 95% CrI: 1.94-2.59), 70-79 (OR 2.90, 95% CrI: 2.49-3.39) and ≥ 80 (OR 4.02, 95% CrI: 3.13-5.20) were independently associated with increasing hospital mortality. Similar results were found in the analysis conducted with an informative prior, as well as between increasing age and post-ECMO complications.

CONCLUSIONS

Among patients receiving V-A ECMO for cardiogenic shock, increasing age is strongly associated with increasing odds of death and complications, and this association emerges as early as 40 years of age.

Temporary ventricular assist device support with a catheter-based axial pump: Changing the paradigm at a pediatric heart center

OBJECTIVE

We report the largest pediatric single-center experience with an Impella (Abiomed Inc) catheter-based axial pump support.

METHODS

We conducted a retrospective cohort study of all patients with acute decompensated heart failure or cardiogenic shock requiring catheter-based axial pump support between October 2014 and February 2022. The primary outcome per individual encounter (hospital admission) was defined as bridge-to-recovery, bridge-to-durable ventricular assist device support, bridge-to-cardiac transplantation, or death at 6 months after catheter-based axial pump explantation. Adverse events were defined according to the Pediatric Interagency Registry for Mechanical Circulatory Support criteria.

RESULTS

Our final study cohort included 37 encounters with 43 catheter-based axial pump implantations. A single catheter-based axial pump device was used for support in 33 encounters (89%), with 2 catheter-based axial pump devices used in 3 (8%) separate encounters and 3 catheter-based axial pump devices used in 1 (3%) encounter. The median [range] age, weight, and body surface area at implantation were 16.8 [6.9-42.8] years, 61.1 [23.1-123.8] kg, and 1.7 [0.8-2.5] m2, respectively. The predominant causes of circulatory failure were graft failure/rejection in 16 patients (43%), followed by cardiomyopathy in 7 patients (19%), arrhythmia refractory to medical therapies in 6 patients (16%), myocarditis/endocarditis in 4 patients (11%), and heart failure due to congenital heart disease in 4 patients (11%). Competing outcomes analysis showed a positive outcome with bridge-to-recovery in 58%, bridge-to-durable VAD support in 14%, and bridge-to-cardiac transplantation in 14% at 6 months. Fourteen percent of encounters resulted in death at 6 months.

CONCLUSIONS

We demonstrate that catheter-based axial pump support in children results in excellent 1- and 6-month survival with an acceptable adverse event profile.

Association of Prophylactic Distal Perfusion Cannulation With Mortality in Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation

Prophylactic distal perfusion cannulation (PDPC) is protectively associated with limb ischemia in patients with cardiogenic shock (CS) receiving femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO). However, evidence supporting its benefits beyond limb ischemia reduction is scarce. We aimed to investigate whether PDPC, compared with no-PDPC, is associated with a lower risk of mortality in patients receiving VA-ECMO. From a multicenter registry, we identified 479 patients who underwent VA-ECMO support for refractory CS. The association of PDPC with 30-day mortality was assessed using multiple methods, including instrumental variable analysis, overlap weighting, and propensity score matching. Of the 479 patients, 154 (32.2%) received PDPC. The 30-day mortality rate was 33.1% in the PDPC group and 53.2% in the no-PDPC group. The instrumental variable analysis showed a protective association of PDPC with 30-day mortality (absolute risk difference -16.7%, 95% confidence interval -31.3% to -2.1%; relative risk 0.68, 95% confidence interval 0.40 to 0.96). The findings were consistent in the overlap-weighted analysis (hazard ratio 0.68, 95% confidence interval 0.48 to 0.98) and in the propensity score-matched analysis (hazard ratio 0.67, 95% confidence interval 0.45 to 1.00). There were no significant differences in safety outcomes, including stroke, ECMO site bleeding, gastrointestinal bleeding, and sepsis, between PDPC and no-PDPC. In conclusion, PDPC was associated with a lower risk of mortality at 30 days in patients with CS receiving VA-ECMO. The efficacy and safety of PDPC merit evaluation in future randomized studies. Clinical trial registration: ClinicalTrials.gov; NCT02985008.

Early Left Ventricular Unloading or Conventional Approach After Venoarterial Extracorporeal Membrane Oxygenation: The EARLY-UNLOAD Randomized Clinical Trial

BACKGROUND

Although venoarterial extracorporeal membrane oxygenation (VA-ECMO) is beneficial for the treatment of profound cardiogenic shock, peripheral VA-ECMO cannulation can increase left ventricular afterload, thus compromising myocardial recovery. We investigated whether early routine left ventricular unloading can reduce 30-day mortality compared with the conventional approach in patients with cardiogenic shock undergoing VA-ECMO.

METHODS

This randomized clinical trial involved 116 patients with cardiogenic shock undergoing VA-ECMO from March 2021 to September 2022 at Chonnam National University Hospital, Gwangju, South Korea. The patients were randomly assigned to undergo either early routine left ventricular unloading with transseptal left atrial cannulation within 12 hours after randomization (n=58) or the conventional approach, which permitted rescue transseptal left atrial cannulation in case of an increased left ventricular afterload (n=58). The primary outcome was all-cause mortality within 30 days.

RESULTS

All 116 randomized patients (mean age, 67.6±13.5 years; 34 [29.3%] women) completed the trial. At 30 days, all-cause death had occurred in 27 (46.6%) patients in the early group and 26 (44.8%) patients in the conventional group (hazard ratio, 1.02 [95% CI, 0.59-1.74]; P=0.942). Crossover to rescue transseptal left atrial cannulation occurred in 29 patients (50%) in the conventional group according to a clear indication. Time to rescue transseptal cannulation in the conventional group was a median of 21.8 (interquartile range, 12.4-52.2) hours after randomization. There were no significant differences in other secondary outcomes between the 2 groups except for a shorter time to disappearance of pulmonary congestion in the early group (median, 3 [interquartile range, 2-6] versus 5 [interquartile range, 3-7] days; P=0.027).

CONCLUSIONS

Among patients with cardiogenic shock undergoing VA-ECMO, early routine left ventricular unloading with transseptal left atrial cannulation did not reduce 30-day mortality compared with the conventional strategy, which permitted rescue transseptal left atrial cannulation. These findings should be cautiously interpreted until the results of multicenter trials using other unloading modalities become available.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04775472.

Early left atrial venting versus conventional treatment for left ventricular decompression during venoarterial extracorporeal membrane oxygenation support: The EVOLVE-ECMO randomized clinical trial

AIMS

Few studies have reported data on the optimal timing of left ventricular (LV) unloading during venoarterial extracorporeal membrane oxygenation (VA-ECMO) for cardiac arrest or shock. This study evaluated the feasibility of an early LV unloading strategy compared with a conventional strategy in VA-ECMO.

METHODS AND RESULTS

Between December 2018 and August 2022, 60 patients at two institutions were randomized in a 1:1 ratio to receive early (n = 30) or conventional (n = 30) LV unloading strategies. The early LV unloading strategy was defined as LV unloading performed at the time of VA-ECMO insertion. LV unloading was performed using a percutaneous transseptal left atrial cannulation via the femoral vein incorporated into the ECMO venous circuit. The early and conventional LV unloading groups included 29 (96.7%) and 23 (76.7%) patients, respectively (median time from VA-ECMO insertion to LV unloading: 48.4 h, interquartile range 47.8-96.5 h). The groups showed no significant differences in the rate of VA-ECMO weaning as the primary endpoint (70.0% vs. 76.7%; relative risk 0.91; 95% confidence interval 0.67-1.24; p = 0.386) and survival to discharge (53.3% vs. 50.0%, p = 0.796). However, the pulmonary congestion score index at 48 h after LV unloading was significantly improved only in the early LV unloading group (2.0 ± 0.7 vs. 1.7 ± 0.6 at baseline vs. at 48 h; p = 0.008).

CONCLUSIONS

Compared with the conventional approach, early LV unloading did not improve the VA-ECMO weaning rate, despite the rapid improvement in pulmonary congestion. Therefore, the results of this study do not support the application of this strategy after VA-ECMO insertion.

Extracorporeal Life Support in Infarct-Related Cardiogenic Shock

BACKGROUND

Extracorporeal life support (ECLS) is increasingly used in the treatment of infarct-related cardiogenic shock despite a lack of evidence regarding its effect on mortality.

METHODS

In this multicenter trial, patients with acute myocardial infarction complicated by cardiogenic shock for whom early revascularization was planned were randomly assigned to receive early ECLS plus usual medical treatment (ECLS group) or usual medical treatment alone (control group). The primary outcome was death from any cause at 30 days. Safety outcomes included bleeding, stroke, and peripheral vascular complications warranting interventional or surgical therapy.

RESULTS

A total of 420 patients underwent randomization, and 417 patients were included in final analyses. At 30 days, death from any cause had occurred in 100 of 209 patients (47.8%) in the ECLS group and in 102 of 208 patients (49.0%) in the control group (relative risk, 0.98; 95% confidence interval [CI], 0.80 to 1.19; P = 0.81). The median duration of mechanical ventilation was 7 days (interquartile range, 4 to 12) in the ECLS group and 5 days (interquartile range, 3 to 9) in the control group (median difference, 1 day; 95% CI, 0 to 2). The safety outcome consisting of moderate or severe bleeding occurred in 23.4% of the patients in the ECLS group and in 9.6% of those in the control group (relative risk, 2.44; 95% CI, 1.50 to 3.95); peripheral vascular complications warranting intervention occurred in 11.0% and 3.8%, respectively (relative risk, 2.86; 95% CI, 1.31 to 6.25).

CONCLUSIONS

In patients with acute myocardial infarction complicated by cardiogenic shock with planned early revascularization, the risk of death from any cause at the 30-day follow-up was not lower among the patients who received ECLS therapy than among those who received medical therapy alone. (Funded by the Else Kröner Fresenius Foundation and others; ECLS-SHOCK ClinicalTrials.gov number, NCT03637205.).

Perioperative Management of Heart Transplantation: A Clinical Review

In this clinical review, the authors summarize the perioperative management of heart transplant patients with a focus on hemodynamics, immunosuppressive strategies, hemostasis and hemorrage, and the prevention and treatment of infectious complications.

Protocolised Management of Cardiogenic Shock and Shock Teams: A Narrative Review

Despite advances in therapy, the incidence of cardiogenic shock continues to increase, with significant mortality that has improved minimally over time. Treatment options for cardiogenic shock are complex and time-, resource-, and case volume-dependent, and involve multiple medical specialties. To provide early, more equitable, and standardised access to cardiogenic shock expertise with advanced therapies, cardiogenic shock teams with a protocolised treatment approach have been proposed. These processes have been applied across hospitals into integrated cardiogenic shock networks. This narrative review evaluates the role of cardiogenic shock teams, protocolised and regionalised shock networks, and the main individual components of protocolised shock management approaches.

Perspectives and Considerations of IABP in the Era of ECMO for Cardiogenic Shock

The development of mechanical circulatory support (MCS) has been rapid, and its use worldwide in patients with cardiogenic shock is increasingly widespread. However, current statistical data and clinical research do not demonstrate its significant improvement in the patient prognosis. This review focuses on the widely used intra-aortic balloon pumps (IABP) and veno-arterial extracorporeal membrane oxygenation (VA-ECMO), analyzing and comparing their characteristics, efficacy, risk of complications, and the current exploration status of left ventricular mechanical unloading. Subsequently, we propose a rational approach to viewing the negative outcomes of current MCS, and look ahead to the future development trends of IABP.

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.

Interactions between extracorporeal support and the cardiopulmonary system

This review describes the intricate physiological interactions involved in the application of extracorporeal therapy, with specific focus on cardiopulmonary relationships. Extracorporeal therapy significantly influences cardiovascular and pulmonary physiology, highlighting the necessity for clinicians to understand these interactions for improved patient care. Veno-arterial extracorporeal membrane oxygenation (veno-arterial ECMO) unloads the right ventricle and increases left ventricular (LV) afterload, potentially exacerbating LV failure and pulmonary edema. Veno-venous (VV) ECMO presents different challenges, where optimal device and ventilator settings remain unknown. Influences on right heart function and native gas exchange as well as end-expiratory lung volumes are important concepts that should be incorporated into daily practice. Future studies should not be limited to large clinical trials focused on mortality but rather address physiological questions to advance the understanding of extracorporeal therapies. This includes exploring optimal device and ventilator settings in VV ECMO, standardizing cardiopulmonary function monitoring strategies, and developing better strategies for device management throughout their use. In this regard, small human or animal studies and computational physiological modeling may contribute valuable insights into optimizing the management of extracorporeal therapies.

Bivalirudin versus heparin anticoagulation in patients receiving extracorporeal membrane oxygenation

OBJECTIVE

Bivalirudin has been suggested as an alternative to heparin for anticoagulation in patients receiving extracorporeal membrane oxygenation (ECMO). Nevertheless, there is limited evidence about the benefit of bivalirudin in ECMO patients compared with heparin. Hence, we conducted a meta-analysis to assess the effect of bivalirudin versus heparin on clinical outcomes in patients receiving ECMO.

METHODS

PubMed, Embase, and the Cochrane Library were systematically searched from inception up to 1 April 2022 for cohort studies and randomized controlled trials comparing bivalirudin versus heparin in patients who received ECMO. The primary outcome was short-term death. Secondary outcomes included thrombotic events and bleeding events.

RESULTS

We selected 12 retrospective cohort studies with 1232 ECMO patients focusing on bivalirudin anticoagulation (n = 497) versus heparin anticoagulation (n = 735). Two hundred and one of 497 patients (40.4%) in the bivalirudin group versus 350 of 735 patients (47.6%) in the heparin group did not survive to hospital discharge. Compared with the heparin group, bivalirudin anticoagulation did not significantly decrease in-hospital mortality in patients receiving ECMO (RR, 0.95; 95% CI, 0.79-1.13; p = 0.546). Fifty-seven of 374 patients (15.2%) in the bivalirudin versus 99 of 381 patients (26.0%) in the heparin group suffered from thrombotic events. Compared with the heparin group, bivalirudin anticoagulation did not significantly decrease the rate of thrombotic events for patients receiving ECMO (RR, 0.78; 95% CI, 0.45-1.35; p = 0.378). However, bivalirudin anticoagulation significantly decreased the incidence of bleeding events compared to the heparin group (RR, 0.48; 95% CI, 0.25-0.95; p = 0.035).

CONCLUSIONS

Compared with heparin anticoagulation, bivalirudin did not decrease the rates of short-term mortality and thrombotic events, but reduced the incidence of bleeding events in patients receiving ECMO.

Advances in the Management of Cardiogenic Shock

OBJECTIVES

To review a contemporary approach to the management of patients with cardiogenic shock (CS).

DATA SOURCES

We reviewed salient medical literature regarding CS.

STUDY SELECTION

We included professional society scientific statements and clinical studies examining outcomes in patients with CS, with a focus on randomized clinical trials.

DATA EXTRACTION

We extracted salient study results and scientific statement recommendations regarding the management of CS.

DATA SYNTHESIS

Professional society recommendations were integrated with evaluated studies.

CONCLUSIONS

CS results in short-term mortality exceeding 30% despite standard therapy. While acute myocardial infarction (AMI) has been the focus of most CS research, heart failure-related CS now predominates at many centers. CS can present with a wide spectrum of shock severity, including patients who are normotensive despite ongoing hypoperfusion. The Society for Cardiovascular Angiography and Intervention Shock Classification categorizes patients with or at risk of CS according to shock severity, which predicts mortality. The CS population includes a heterogeneous mix of phenotypes defined by ventricular function, hemodynamic profile, biomarkers, and other clinical variables. Integrating the shock severity and CS phenotype with nonmodifiable risk factors for mortality can guide clinical decision-making and prognostication. Identifying and treating the cause of CS is crucial for success, including early culprit vessel revascularization for AMI. Vasopressors and inotropes titrated to restore arterial pressure and perfusion are the cornerstone of initial medical therapy for CS. Temporary mechanical circulatory support (MCS) is indicated for appropriately selected patients as a bridge to recovery, decision, durable MCS, or heart transplant. Randomized controlled trials have not demonstrated better survival with the routine use of temporary MCS in patients with CS. Accordingly, a multidisciplinary team-based approach should be used to tailor the type of hemodynamic support to each individual CS patient's needs based on shock severity, phenotype, and exit strategy.

Percutaneous cannulation is associated with lower rate of severe neurological complication in femoro-femoral ECPR: results from the Extracorporeal Life Support Organization Registry

BACKGROUND

Percutaneous cannulation is now accepted as the first-line strategy for extracorporeal cardiopulmonary resuscitation (ECPR) in adults. However, previous studies comparing percutaneous cannulation to surgical cannulation have been limited by small sample size and single-center settings. This study aimed to compare in-hospital outcomes in cardiac arrest (CA) patients who received femoro-femoral ECPR with percutaneous vs surgical cannulation.

METHODS

Adults with refractory CA treated with percutaneous (percutaneous group) or surgical (surgical group) femoro-femoral ECPR between January 2008 and December 2019 were extracted from the international Extracorporeal Life Support Organization registry. The primary outcome was severe neurological complication. Multivariable logistic regression analyses were performed to assess the association between percutaneous cannulation and in-hospital outcomes.

RESULTS

Among 3575 patients meeting study inclusion, 2749 (77%) underwent percutaneous cannulation. The proportion of patients undergoing percutaneous cannulation increased from 18% to 89% over the study period (p < 0.001 for trend). Severe neurological complication (13% vs 19%; p < 0.001) occurred less frequently in the percutaneous group compared to the surgical group. In adjusted analyses, percutaneous cannulation was independently associated with lower rate of severe neurological complication (odds ratio [OR] 0.62; 95% CI 0.46-0.83; p = 0.002), similar rates of in-hospital mortality (OR 0.93; 95% CI 0.73-1.17; p = 0.522), limb ischemia (OR 0.84; 95% CI 0.58-1.20; p = 0.341) and cannulation site bleeding (OR 0.90; 95% CI 0.66-1.22; p = 0.471). The comparison of outcomes provided similar results across different levels of center percutaneous experience or center ECPR volume.

CONCLUSIONS

Among adults receiving ECPR, percutaneous cannulation was associated with probable lower rate of severe neurological complication, and similar rates of in-hospital mortality, limb ischemia and cannulation site bleeding.

Extracorporeal Membrane Oxygenation (VA-ECMO) in Management of Cardiogenic Shock

Cardiogenic shock is a critical condition of low cardiac output resulting in insufficient systemic perfusion and end-organ dysfunction. Though significant advances have been achieved in reperfusion therapy and mechanical circulatory support, cardiogenic shock continues to be a life-threatening condition associated with a high rate of complications and excessively high patient mortality, reported to be between 35% and 50%. Extracorporeal membrane oxygenation can provide full cardiopulmonary support, has been increasingly used in the last two decades, and can be used to restore systemic end-organ hypoperfusion. However, a paucity of randomized controlled trials in combination with high complication and mortality rates suggest the need for more research to better define its efficacy, safety, and optimal patient selection. In this review, we provide an updated review on VA-ECMO, with an emphasis on its application in cardiogenic shock, including indications and contraindications, expected hemodynamic and echocardiographic findings, recommendations for weaning, complications, and outcomes. Furthermore, specific emphasis will be devoted to the two published randomized controlled trials recently presented in this setting.

Transvalvular Unloading Mitigates Ventricular Injury Due to Venoarterial Extracorporeal Membrane Oxygenation in Acute Myocardial Infarction

Whether extracorporeal membrane oxygenation (ECMO) with Impella, known as EC-Pella, limits cardiac damage in acute myocardial infarction remains unknown. The authors now report that the combination of transvalvular unloading and ECMO (EC-Pella) initiated before reperfusion reduced infarct size compared with ECMO alone before reperfusion in a preclinical model of acute myocardial infarction. EC-Pella also reduced left ventricular pressure-volume area when transvalvular unloading was applied before, not after, activation of ECMO. The authors further observed that EC-Pella increased cardioprotective signaling but failed to rescue mitochondrial dysfunction compared with ECMO alone. These findings suggest that ECMO can increase infarct size in acute myocardial infarction and that EC-Pella can mitigate this effect but also suggest that left ventricular unloading and myocardial salvage may be uncoupled in the presence of ECMO in acute myocardial infarction. These observations implicate mechanisms beyond hemodynamic load as part of the injury cascade associated with ECMO in acute myocardial infarction.

Mechanical circulatory support for adults in Japan: A 10-year perspective

Globalization in Asia and consequent strengthening of healthcare economic factors in tandem with an increasing heart failure (HF) population have enhanced potential for development and progress in the fields of HF medicine and mechanical circulatory support (MCS). In Japan, there are unique opportunities to investigate the outcome of acute and chronic MCS and a national registry for percutaneous and implantable left ventricular assist device (LVAD) including Impella pumps has been established. A Peripheral extracorporeal membrane oxygenation (ECMO) for acute MCS has been used in more than 7000 patients annually and Impella usage in more than 4000 patients over the past 4 years was noted. Recently, a novel centrifugal pump with hydrodynamically levitated impeller was developed and approved for mid-term extracorporeal circulatory support. In terms of chronic MCS more than 1200 continuous flow LVADs have been implanted during the past decade, and 2-year survival rate after primary LVAD implantation is 91%. Because of donor organ shortage, more than 70% of heart transplant recipients required LVAD support for more than 3 years and prevention and treatment of complications during long-term LVAD support have become important. Five important topics including hemocompatibility-related complications, LVAD infections, aortic valve insufficiency, right ventricular failure and cardiac recovery during LVAD support are discussed in this review for improving clinical outcomes. Findings from Japan will continue to provide useful information regarding MCS for the Asia-Pacific region and beyond.