Venting during venoarterial extracorporeal membrane oxygenation

Impact of left ventricular unloading on postheart transplantation outcomes in patients bridged with VA-ECMO

INTRODUCTION AND OBJECTIVES

The impact of preoperative left ventricular (LV) unloading on postoperative outcomes in patients bridged with venoarterial extracorporeal membrane oxygenation (VA-ECMO) to heart transplantation (HT) is unknown. Our aim was to compare posttransplant outcomes in patients bridged to HT with VA-ECMO, with or without the use of different mechanical strategies for LV decompression.

METHODS

We conducted a retrospective analysis of the postoperative outcomes of consecutive HT candidates bridged with VA-ECMO, with or without concomitant LV unloading. Patients were included from 16 Spanish centers from 2010 to 2020. The primary endpoint was 1-year post-HT survival, which was assessed using Cox regression.

RESULTS

Overall, 245 patients underwent high-emergency HT while supported with VA-ECMO. A mechanical strategy for LV unloading was used in 133 (54.3%) patients, with the intra-aortic balloon pump being the most commonly used method (n=112; 84.2%). One-year posttransplant survival was 74.4% in the LV unloading group and 59.8% in the control group (P=.025). In multivariate analyses, preoperative LV unloading was independently associated with lower 1-year mortality (adjusted HR, 0.50; 95%CI, 0.32-0.78; P=.003). This association was observed both in patients managed with an intra-aortic balloon pump alone (adjusted HR, 0.52; 95%CI, 0.32-0.84; P=.007) and with other strategies for mechanical LV unloading (adjusted HR, 0.43; 95%CI, 0.19-0.97; P=.042). No significant differences were found between groups regarding other postoperative complications.

CONCLUSIONS

Preoperative LV unloading was independently associated with increased 1-year posttransplant survival in candidates bridged with VA-ECMO.

Mechanical circulatory support for patients with infarct-related cardiogenic shock: a state-of-the-art review

Acute myocardial infarction-related cardiogenic shock (AMI-CS) is a severe, life-threatening condition characterised by inadequate tissue perfusion due to the heart's inability to pump blood effectively. The pathophysiology of AMI-CS usually arises from the sudden loss of myocardial contractility, leading to a decrease in cardiac output and systemic hypoperfusion. In approximately 90% of AMI-CS cases, the left ventricle is the primary site of dysfunction.Despite early recognition and the implementation of strategies such as primary percutaneous coronary intervention, the mortality rate associated with AMI-CS remains alarmingly high, reflecting significant unmet clinical needs. A major challenge lies in identifying the optimal patient population for mechanical circulatory support (MCS) devices, as these interventions are costly and can lead to serious complications.This review provides a comprehensive overview of the pathophysiological mechanisms underlying AMI-CS, explores the current range of MCS devices available and offers an in-depth discussion on the balance of benefits and risks associated with these devices. By highlighting key evidence from recent studies, we aim to shed light on the clinical decision-making process and improve outcomes in this high-risk patient population.

2025 American Association for Thoracic Surgery (AATS) Expert Consensus Document: Surgical management of acute myocardial infarction and associated complications

BACKGROUND

Complications of acute myocardial infarction (AMI) can result in significant morbidity and mortality. This document reports the findings and recommendations of a multidisciplinary group of experts on the management of patients with complications of AMI, with particular focus on the use of mechanical circulatory support in this context.

METHODS

Through the American Association of Thoracic Surgery Clinical Practice Standards Committee, a committee of multidisciplinary experts, including both cardiologists and cardiothoracic surgeons, was established. A list of topics was developed. Committee members were divided into subgroups that developed relevant questions. A systematic literature review was then performed, and the results were synthesized into clinical recommendations. Expert consensus was then established using the Delphi process.

RESULTS

Based on the results of the systematic literature review, as well as the clinical expertise of the committee, clinical recommendations were developed. Each of these recommendations, the strength of each recommendation, and the level or quality of evidence on which the recommendation was based are presented here. Topics addressed include general considerations, revascularization strategies, cardiogenic shock, papillary muscle rupture, postinfarction ventricular septal defect, free wall rupture, arrhythmias, and the use of durable therapies in this context.

CONCLUSIONS

AMI may result in cardiogenic shock, malignant arrhythmias, or mechanical complications, each of which is associated with high mortality. Prompt management of these complications, including consideration for mechanical circulatory support, is warranted.

Clinical and Preclinical Evidence on a Novel Percutaneous Pulsatile Ventricular Assist Device (PulseCath): Protocol for a Scoping Review

Background and Aims

Temporary mechanical circulatory support (tMCS) devices play a crucial role in improving survival for patients with hemodynamic instability by providing cardiac assistance, and may serve as either a bridge to recovery or destination therapy. Recently, the PulseCath (iVAC2L and iVAC3L) has been introduced into the broader tMCS landscape. Due to its ease of implantation and low cost, it appears to enhance and complement the spectrum of tMCS devices. This planned scoping review aims to summarize the potential applications and reported side effects of PulseCath, while elucidating its underlying pathophysiological principles and hemodynamic effects, incorporating both preclinical in vivo and clinical published data.

Methods

We will perform a scoping review in accordance to the JBI methodology and the extension for Scoping Reviews of the PRISMA checklist. We will conduct a comprehensive search of PubMed/MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, and Google Scholar (from their inception until February 28, 2025) to identify and retrieve preclinical in vivo and clinical investigations on the implantation of the PulseCath. EndNote X9 and Rayyan softwares will be used to aid article selection. Standardized forms will be employed for subsequent data charting and extraction. The ROBINS-I and RoB2 tools will be employed to perform a formal assessment of the risk of bias of included studies.

Results

Included studies will be categorized into two groups: preclinical in vivo and clinical. The clinical studies will be further classified according to implantation strategy, either pre-emptive or bail-out. The main findings from the selected studies will be presented through a narrative synthesis. If sufficient homogeneity exists among the studies, the presentation of quantitative data will be conducted. Tables and figures will be used to aid in the illustration of the findings.

Conclusion

The planned scoping review will systematically examine the existing evidence on the hemodynamic effects, pathophysiology, and potential complications of PulseCath, ultimately seeking to delineate optimal clinical settings for its use. The findings could highlight research gaps in tMCS support and expand the clinical application of PulseCath, thus improving patient outcomes and enhancing clinicians' understanding of this novel device.

Different Mechanical Circulatory Support Strategies for Infarct-Related Cardiogenic Shock: A Subanalysis of the ECLS-SHOCK Trial

BACKGROUND

Mechanical circulatory support (MCS) devices are frequently used in patients with acute myocardial infarction complicated by cardiogenic shock. In clinical practice, escalation of MCS device therapy is performed in a significant proportion of patients aiming to improve hemodynamic status.

OBJECTIVES

The aim of this study was to analyze outcomes of different MCS device strategies in the ECLS-SHOCK (Extracorporeal Life Support in Cardiogenic Shock) trial.

METHODS

The present subanalysis from the ECLS-SHOCK trial analyzed outcomes of patients treated with upfront extracorporeal life support (ECLS) only, bailout MCS, and escalated MCS therapy. The primary outcome was 30-day all-cause mortality.

RESULTS

Upfront ECLS only, bailout MCS, and escalated MCS therapy were used in 165 (78.9%), 54 (26.0%), and 27 (12.9%) patients, respectively. Thirty-day all-cause mortality was 44.8% (95% CI: 37.1%-52.8%), 61.1% (95% CI: 46.9%-74.1%), and 55.6% (95% CI: 35.3%-74.5%) in the upfront ECLS, bailout MCS, and escalated MCS group (P = 0.09). Need for renal replacement therapy was higher in the bailout MCS (35.2%; 95% CI: 22.7%-49.4%) than in upfront ECLS (7.3%; 95% CI: 3.8%-12.4%) and escalated MCS (14.8%; 95% CI: 4.2%-33.8%) (P < 0.001). Moderate or severe bleeding complications were similar in the upfront ECLS (25.5%; 95% CI: 19.0%-32.8%), bailout MCS (22.2%; 95% CI: 12.0%-35.6%), and escalated MCS (22.2%; 95% CI: 8.6%-42.3%) group (P = 0.86).

CONCLUSIONS

Bailout and escalated MCS therapy is associated with numerically higher 30-day mortality compared with upfront ECLS use only. Bailout MCS use is also associated with higher need for renal replacement therapy. (Extracorporeal Life Support in Cardiogenic Shock [ECLS-SHOCK]; NCT03637205).

Transaortic Catheter Venting for Left Ventricular Unloading in Veno-Arterial Extracorporeal Life Support: A Porcine Cardiogenic Shock Model

Background and Objectives: Left ventricle (LV) overloading during veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) is detrimental to myocardial recovery. To determine whether LV unloading using transaortic catheter venting (TACV) is effective, we analyzed the effect of TACV in a human-sized porcine model. Materials and Methods: Hypoxic biventricular dysfunction was induced in 11 pigs using femoro-femoral VA-ECMO and custom-made TACV catheters in the LV through the common carotid artery. Hemodynamic conditions were then simulated. The TACV was either opened or closed under a controlled ECMO flow. Conversely, the ECMO flow was adjusted, varying from 1 L to 4 L, with and without TACV; 2115 observations were collected. Results: In comparing observations without TACV (TACV-) and with TACV (TACV+), the change in left ventricular end-diastolic pressure (LVEDP) after TACV application was -1.2 mmHg (p < 0.001). In the linear regression model, the reduction in LVEDP was maximized when the baseline LVEDP and ECMO flow were higher. When escalating the ECMO flow in the respective settings of TACV- and TACV+, the rise in LVEDP was significantly lower in TACV+. Conclusions: TACV decreased LVEDP; this effect was more prominent when ECMO flow and baseline LVEDP were higher. These findings suggest that TACV might support LV recovery through effective unloading, even when ECMO flow is high.

Useful central mechanical circulatory support system for critical biventricular heart failure associated with high pulmonary vascular resistance

BACKGROUND

Peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) is a powerful life-saving tool; however, it can sometimes induce severe pulmonary edema in patients with critical heart failure. We report favorable outcomes in critically ill patients by using a central ECMO system with an innovative blood perfusion method.

METHODS

We analyzed 10 patients with severe heart failure and pulmonary edema who were treated with the central ECMO system at our institution between April 2022 and October 2023. The system consists of central cannulation with two inflows from the right atrium and left ventricle, and two outflows to the aorta and pulmonary artery, connected by two Y-connectors to a single ECMO circuit (RALV-AOPA ECMO). In this system, blood flow to the pulmonary artery is adjusted and mean pulmonary artery pressure is limited to <20 mm Hg, which reduces right ventricular afterload and prevents the worsening of pulmonary edema and hemorrhage.

RESULTS

Six patients were diagnosed with fulminant lymphocytic myocarditis, and four were diagnosed with coronavirus disease 2019-related myocardial injury. The ejection fraction was 6.5 ± 4.1%. The average intraoperative pulmonary vascular resistance was 4.6 ± 1.3 Wood units. After 24 h, the mean pulmonary arterial pressure was 12.8 ± 4.3 mm Hg, and pulmonary vascular resistance was 1.5 ± 0.3 Wood units. The duration of central RALV-AOPA ECMO was 3.7 ± 2.1 days. Finally, six patients were weaned, three received HeartMate3, and one received heart transplantation. At follow-up, all patients remained alive (428 ± 208 days), and two patients experienced cerebrovascular accidents without any lasting sequelae.

CONCLUSIONS

The central RALV-AOPA ECMO is an innovative system that achieves early improvement in pulmonary vascular resistance and is safe and feasible for patients with acute biventricular failure and pulmonary edema.

Variability in triggers for mechanical left ventricular unloading in VA-ECMO: A literature search

BACKGROUND

Venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO) is a means of supporting the lungs or the heart and lungs in patients with hemodynamic compromise that is refractory to conventional measures. VA-ECMO is most commonly deployed in a percutaneous fashion with femoral arterial and venous access. While VA-ECMO, particularly in a femoral-femoral configuration, provides both hemodynamic and ventilatory support, it also causes increased afterload on the left ventricle (LV) which in turn may result in LV distension (LVD). LV thrombus formation, ventricular arrhythmias, pulmonary edema, and pulmonary hemorrhage are clinical manifestations of LVD. LV unloading is a means of preventing LVD and its sequelae. If less invasive methods fail to achieve adequate LV unloading, invasive mechanical methods are pursued such as intra-aortic balloon pump counter-pulsation, atrial septostomy, surgical venting, left atrial cannulation, and percutaneous transvalvular micro-axial pump placement.

METHODS

We sought to review indicators of LVD, thresholds, and options for mechanical venting strategies. A Pubmed search was performed to identify current literature about LV unloading for VA ECMO. This was categorized and summarized to determine commonly reported thresholds for mechanical LV unloading.

RESULTS

Multiple physiologic and radiographic indicators were reported without uniformity. Common indicators included increased pulmonary artery catheter pressures, decreased Aortic Line Pulse Pressure, as well as multiple Echocardiographic, and radiographic indicators.

CONCLUSION

Although there has been significant interest in the topic, there is currently limited uniformity in thresholds for when to initiate and escalate mechanical LV unloading. While the method of LV unloading is an active area of investigation, the threshold for which to initiate invasive venting strategies is largely unexplored.

Effectiveness of an Impella Versus Intra-Aortic Balloon Pump in Patients Who Received Extracorporeal Membrane Oxygenation

BACKGROUND

It is unclear whether an intra-aortic balloon pump (IABP) or percutaneous ventricular assist device (Impella) in combination with extracorporeal membrane oxygenation (ECMO) is better.

METHODS

Using the Japanese Diagnosis Procedure Combination database from September 2016 to March 2022, we identified inpatients who received an Impella or IABP in combination with ECMO (ECPella or ECMO+IABP group, respectively). The primary outcome was in-hospital mortality, and the secondary outcomes included the length of hospital stay, length of ECMO, total hospitalization cost, complications, and durable mechanical circulatory support implantations. Propensity score matching was performed to compare the outcomes between the groups.

RESULTS

Of 14 319 eligible patients, 590 (4.1%) received ECPella and 13 729 (96%) received ECMO+IABP. The mean age of patients was 65 years, 77% were men, and 57% had acute coronary syndrome. After propensity score matching, the patient characteristics were well balanced between the groups. The 14-day mortality rate was lower in the ECPella group than in the ECMO+IABP group (28.0% versus 36.8%; risk difference, -8.2% [95% CI, -13.8 to -2.7]), whereas there was no significant difference in in-hospital mortality between the groups (58.3% versus 56.6%; risk difference, 2.4% [95% CI, -3.5 to 8.2]). The ECPella group had a higher total hospitalization cost, increased renal replacement therapy during hospitalization, and more durable mechanical circulatory support implantations than the ECMO+IABP group.

CONCLUSIONS

This nationwide inpatient database study showed no significant difference in in-hospital mortality between the groups, but ECPella was associated with a higher total hospitalization cost, increased renal replacement therapy during hospitalization, and more durable mechanical circulatory support implantations than ECMO+IABP.

A randomized embedded multifactorial adaptive platform for extra corporeal membrane oxygenation (REMAP ECMO) - design and rationale of the left ventricular unloading trial domain

BACKGROUND

The use of Extracorporeal Membrane Oxygenation (ECMO) remains associated with high rates of complications, weaning failure and mortality which can be partly explained by a knowledge gap on how to properly manage patients on ECMO support. To address relevant patient management issues, we designed a "Randomized Embedded Multifactorial Adaptive Platform (REMAP)" in the setting of ECMO (REMAP ECMO) and a first embedded randomized controlled trial (RCT) investigating the effects of routine early left ventricular (LV) unloading through intra-aortic balloon pumping (IABP).

METHODS

REMAP ECMO describes a registry-based platform allowing for the embedding of multiple response adaptive RCTs (trial domains) which can perpetually address the effect of relevant patient management issues on ECMO weaning success. A first trial domain studies the effects of LV unloading by means of an IABP as an adjunct to veno-arterial (V-A) ECMO versus V-A ECMO alone on ECMO weaning success at 30 days in adult cardiogenic shock patients admitted to the Intensive Care Unit (ICU). The primary outcome of this trial is "successful weaning from ECMO" being defined as a composite of survival without the need for mechanical circulatory support, heart transplantation, or left ventricular assist device (LVAD) at 30 days after initiation of ECMO. Secondary outcomes include the need for interventional escalation of LV unloading strategy, mechanistic endpoints, survival characteristics until 1 year after ECMO initiation, and quality of life. Trial data will be analysed using a Bayesian statistical framework. The adaptive design allows for a high degree of flexibility, such as response adaptive randomization and early stopping of the trial for efficacy or futility. The REMAP ECMO LV unloading study is approved by the Medical Ethical Committee of the Erasmus Medical Center and is publicly registered.

CONCLUSION

This REMAP ECMO trial platform enables the efficient roll-out of multiple RCTs on relevant patient management issues. A first embedded trial domain will compare routine LV unloading by means of an IABP as an adjunct to V-A ECMO versus V-A ECMO alone.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05913622.

Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) Support in New Era of Heart Transplant

Heart failure is a serious and challenging medical condition characterized by the inability of the heart to pump blood effectively, leading to reduced blood flow to organs and tissues. Several underlying causes may be linked to this, including coronary artery disease, hypertension, or previous heart attacks. Therefore, it is a chronic condition that requires ongoing management and medical attention. HF affects >64 million individuals worldwide. Heart transplantation remains the gold standard of treatment for patients with end-stage cardiomyopathy. The recruitment of marginal donors may be considered an asset at the age of cardiac donor organ shortage. Primary graft dysfunction (PGD) is becoming increasingly common in the new era of heart transplantations. PGD is the most common cause of death within 30 days of cardiac transplantation. Mechanical Circulatory Support (MCS), particularly venoarterial extracorporeal membrane oxygenation (V-A ECMO), is the only effective treatment for severe PGD. VA-ECMO support ensures organ perfusion and provides the transplanted heart with adequate rest and recovery. In the new era of heart transplantation, early use allows for increased patient survival and careful management reduces complications.

Impact of Left Ventricular Venting on Acute Brain Injury in Patients with Cardiogenic Shock: An Extracorporeal Life Support Organization Registry Analysis

Background

While left ventricular (LV) venting reduces LV distension in cardiogenic shock patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO), it may also amplify risk of acute brain injury (ABI). We investigated the hypothesis that LV venting is associated with increased risk of ABI. We also compared ABI risk of the two most common LV venting strategies, percutaneous microaxial flow pump (mAFP) and intra-aortic balloon pump (IABP).

Methods

The Extracorporeal Life Support Organization registry was queried for patients on peripheral VA-ECMO for cardiogenic shock (2013-2024). ABI was defined as hypoxic-ischemic brain injury, ischemic stroke, or intracranial hemorrhage. Secondary outcome was hospital mortality. We compared no LV venting with 1) LV venting, 2) mAFP, and 3) IABP using multivariable logistic regression. To compare ABI risk of mAFP vs. IABP, propensity score matching was performed.

Results

Of 13,276 patients (median age=58.2, 69.9% male), 1,456 (11.0%) received LV venting (65.5% mAFP and 29.9% IABP), and 525 (4.0%) had ABI. After multivariable regression, LV-vented patients had increased odds of ABI (adjusted odds ratio (aOR)=1.76, 95% CI=1.29, 2.37, p<0.001) but no difference in mortality (aOR=1.08, 95% CI=0.91-1.28, p=0.39) compared to non-LV-vented patients. In the propensity- matched cohort of IABP (n=231) vs. mAFP (n=231) patients, there was no significant difference in odds of ABI (aOR=1.35, 95%CI=0.69-2.71, p=0.39) or mortality (aOR=0.88, 95%CI=0.58-1.31, p=0.52).

Conclusions

LV venting was associated with increased odds of ABI but not mortality in patients receiving peripheral VA-ECMO for cardiogenic shock. There was no difference in odds of ABI or mortality for IABP vs. mAFP patients.

Clinical Perspective

In patients receiving peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) for cardiogenic shock, left ventricular venting is associated with increased odds of acute brain injury (ABI) but not mortality. However, mode of venting-intra-aortic balloon pump (IABP) or percutaneous microaxial flow pump (mAFP)-does not appear to impact either odds of ABI or mortality. These findings highlight a link between venting strategies and neurological outcomes in this high-risk population. Clinicians must weigh the benefits of venting against ABI risk when managing neurocritically ill patients, though our findings provide reassurance clinicians that both IABP and mAFP may offer comparable neurologic safety profiles.

Cardiogenic shock

Cardiogenic shock is a complex syndrome defined by systemic hypoperfusion and inadequate cardiac output arising from a wide array of underlying causes. Although the understanding of cardiogenic shock epidemiology, specific subphenotypes, haemodynamics, and cardiogenic shock severity staging has evolved, few therapeutic interventions have shown survival benefit. Results from seminal randomised controlled trials support early revascularisation of the culprit vessel in infarct-related cardiogenic shock and provide evidence of improved survival with the use of temporary circulatory support in selected patients. However, numerous questions remain unanswered, including optimal pharmacotherapy regimens, the role of mechanical circulatory support devices, management of secondary organ dysfunction, and best supportive care. This Review summarises current definitions, pathophysiological principles, and management approaches in cardiogenic shock, and highlights key knowledge gaps to advance individualised shock therapy and the evidence-based ethical use of modern technology and resources in cardiogenic shock.

ECMO Alone Versus ECPELLA in Patients Affected by Cardiogenic Shock: The Multicenter EVACS Study

The objective was to investigate the outcomes of concomitant venoarterial extracorporeal membrane oxygenation (ECMO) and left ventricular unloading with Impella (ECPELLA) compared with ECMO alone to treat patients affected by cardiogenic shock. Data from patients needing mechanical circulatory support from 4 international centers were analyzed. Of 438 patients included, ECMO alone and ECPELLA were adopted in 319 (72.8%) and 119 (27.2%) patients, respectively. Propensity score matching analysis identified 95 pairs. In the matched cohort, 30-day mortality rates in the ECMO and ECPELLA were 49.5% and 43.2% ( P = 0.467). The incidences of complications did not differ significantly between groups ( P = 0.877, P = 0.629, P = 1.000, respectively). After a median follow-up of 0.18 years (interquartile range 0.02-2.55), the use of ECPELLA was associated with similar mortality compared with ECMO alone (hazard ratio 0.81, 95% confidence interval 0.54-1.20, P = 0.285), with 1-year overall survival rates of 51.3% and 46.6%, for ECPELLA and ECMO alone, respectively. ECMO alone and ECPELLA are both effective strategies in patients needing mechanical circulatory support for cardiogenic shock, showing similar rates of early and mid-term survival.

Left ventricle unloading during veno-arterial extracorporeal membrane oxygenation: review with updated evidence

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is widely used to treat medically refractory cardiogenic shock and cardiac arrest, and its usage has increased exponentially over time. Although VA-ECMO has many advantages over other mechanical circulatory supports, it has the unavoidable disadvantage of increasing retrograde arterial flow in the afterload, which causes left ventricular (LV) overload and can lead to undesirable consequences during VA-ECMO treatment. Weak or no antegrade flow without sufficient opening of the aortic valve increases the LV end-diastolic pressure, and that can cause refractory pulmonary edema, blood stagnation, thrombosis, and refractory ventricular arrhythmia. This hemodynamic change is also related to an increase in myocardial energy consumption and poor recovery, making LV unloading an essential management issue during VA-ECMO treatment. The principal factors in effective LV unloading are its timing, indications, and modalities. In this article, we review why LV unloading is required, when it is indicated, and how it can be achieved.

Factors Influencing Successful Weaning From Venoarterial Extracorporeal Membrane Oxygenation: A Systematic Review

With advancements in extracorporeal life support (ECLS) technologies, venoarterial extracorporeal membrane oxygenation (VA-ECMO) has emerged as a crucial cardiopulmonary support mechanism. This review explores the significance of VA-ECMO system configuration, cannulation strategies, and timing of initiation. Through an analysis of medication management strategies, complication management, and comprehensive preweaning assessments, it aims to establish a multidimensional evaluation framework to assist clinicians in making informed decisions regarding weaning from VA-ECMO, thereby ensuring the safe and effective transition of patients.

A comparative study of femoral artery and combined femoral and axillary artery cannulation in veno-arterial extracorporeal membrane oxygenation patients

Objective

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a critical support technique for cardiac surgery patients. This study compares the outcomes of femoral artery cannulation vs. combined femoral and axillary artery cannulation in post-cardiotomy VA-ECMO patients. This study aimed to compare the clinical outcomes of critically ill patients post-cardiac surgery under VA-ECMO support using different cannulation strategies. Specifically, the focus was on the impact of femoral artery (FA) cannulation vs. combined femoral artery and axillary artery (FA+AA) cannulation on patient outcomes.

Methods

Through a retrospective analysis, we compared 51 adult patients who underwent cardiac surgery and received VA-ECMO support based on the cannulation strategy employed-FA cannulation in 27 cases vs. FA+AA cannulation in 24 cases.

Results

The FA+AA group showed significant advantages over the FA group in terms of the incidence of chronic renal failure (CRF) (37.50% vs. 14.81%, p = 0.045), preoperative blood filtration requirement (37.50% vs. 11.11%, p = 0.016), decreased platelet count (82.67 ± 44.95 vs. 147.33 ± 108.79, p = 0.014), and elevated creatinine (Cr) levels (151.80 ± 60.73 vs. 110.26 ± 57.99, p = 0.041), although the two groups had similar 30-day mortality rates (FA group 40.74%, FA+AA group 33.33%). These findings underscore that a combined approach may offer more effective hemodynamic support and better clinical outcomes when selecting an ECMO cannulation strategy.

Conclusion

Despite the FA+AA group patients presenting with more preoperative risk factors, this group has exhibited lower rates of complications and faster recovery during ECMO treatment. While there has been no significant difference in 30-day mortality rates between the two cannulation strategies, the FA+AA approach may be more effective in reducing complications and improving limb ischemia. These findings highlight the importance of individualized treatment strategies and meticulous monitoring in managing post-cardiac surgery ECMO patients.

A case of metformin-associated lactic acidosis with cardiogenic and vasoplegic shock supported by ECPella

Metfomin-associated lactic acidosis (MALA) is a rare but life-threatening complication of metformin use. We present a case of MALA with concurrent cardiogenic and vasoplegic shock which was successfully supported by ECPella (concurrent use of VA-ECMO and Impella). Early recognition, aggressive hemodynamic support with ECPella and early hemodialysis can be life-saving. Monitoring of both lactate and SvO2 trends can help understand the response to treatment.

Unloading in cardiogenic shock: the rationale and current evidence

PURPOSE OF REVIEW

Discussing the rationale and current evidence for left ventricular unloading in cardiogenic shock.

RECENT FINDINGS

Microaxial flow pumps (MFP) and intra-aortic balloon pumps (IABP) augment cardiac output while simultaneously unloading the left ventricle (e.g. reducing left ventricular pressure), thereby targeting a key mechanism of cardiogenic shock. A recent randomized trial has shown a mortality reduction with MFP in selected patients with cardiogenic shock, strengthening the rationale for this strategy, although the evidence for the IABP is so far neutral. MFP/IABP can also be used concomitantly with veno-arterial extracorporeal membrane oxygenation (va-ECMO) to alleviate the va-ECMO-related increase in left ventricular afterload, to facilitate weaning and ultimately to improve myocardial recovery and prognosis of affected patients. However, the use of MFP/IABP in this indication solely relies on retrospective data, which need to be interpreted with caution, especially as these strategies are associated with more complications. Currently ongoing randomized trials will help to further clarify the role of left ventricular unloading in patients on va-ECMO.

SUMMARY

Left ventricular unloading addresses a key mechanism of cardiogenic shock, with strong evidence to support MFP use in selected patients, but further randomized controlled trials are required to clarify the role of different devices/strategies for the overall shock population.

Scrutinizing the Role of Venoarterial Extracorporeal Membrane Oxygenation: Has Clinical Practice Outpaced the Evidence?

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for temporary mechanical circulatory support in various clinical scenarios has been increasing consistently, despite the lack of sufficient evidence regarding its benefit and safety from adequately powered randomized controlled trials. Although the ARREST trial (Advanced Reperfusion Strategies for Patients with Out-of-Hospital Cardiac Arrest and Refractory Ventricular Fibrillation) and a secondary analysis of the PRAGUE OHCA trial (Prague Out-of-Hospital Cardiac Arrest) provided some evidence in favor of VA-ECMO in the setting of out-of-hospital cardiac arrest, the INCEPTION trial (Early Initiation of Extracorporeal Life Support in Refractory Out-of-Hospital Cardiac Arrest) has not found a relevant improvement of short-term mortality with extracorporeal cardiopulmonary resuscitation. In addition, the results of the recently published ECLS-SHOCK trial (Extracorporeal Life Support in Cardiogenic Shock) and ECMO-CS trial (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock) discourage the routine use of VA-ECMO in patients with infarct-related cardiogenic shock. Ongoing clinical trials (ANCHOR [Assessment of ECMO in Acute Myocardial Infarction Cardiogenic Shock, NCT04184635], REVERSE [Impella CP With VA ECMO for Cardiogenic Shock, NCT03431467], UNLOAD ECMO [Left Ventricular Unloading to Improve Outcome in Cardiogenic Shock Patients on VA-ECMO, NCT05577195], PIONEER [Hemodynamic Support With ECMO and IABP in Elective Complex High-risk PCI, NCT04045873]) may clarify the usefulness of VA-ECMO in specific patient subpopulations and the efficacy of combined mechanical circulatory support strategies. Pending further data to refine patient selection and management recommendations for VA-ECMO, it remains uncertain whether the present usage of this device improves outcomes.

[Treatment of cardiogenic shock due to right ventricular involvement]

The right ventricle is susceptible to changes in preload, afterload, and contractility. The answer is its dilation with dysfunction/acute failure; filling is limited to the left ventricle and cardiac output. Systemic venous congestion is retrograde to the right heart, it is involved in the genesis of cardiogenic shock due to right ventricle involvement. This form of shock is less well known than that which occurs due to left ventricular failure, therefore, treatment may differ. Once the primary treatment has been carried out, since no response is obtained, supportive treatment aimed at ventricular pathophysiology will be the next option. It is suggested to evaluate the preload for the reasoned indication of liquids, diuretics or even ultrafiltration. Restore or maintain heart rate and sinus rhythm, treat symptomatic bradycardia, arrhythmias that make patients unstable, use of temporary pacing or cardioversion procedures. Improving contractility and vasomotility, using vasopressors and inotropes, alone or in combination, the objective will be to improve right coronary perfusion pressure. Balance the effect of drugs and maneuvers on preload and/or afterload, such as mechanical ventilation, atrial septostomy and pulmonary vasodilators. And the increasing utility of mechanical support of the circulation that has become a useful tool to preserve/restore right heart function.

[Extracorporeal cardiopulmonary resuscitation-When the heart no longer functions]

Extracorporeal cardiopulmonary resuscitation (ECPR) is an option for restoring blood circulation in patients with refractory circulatory failure. While conventional resuscitation measures are being continued, venoarterial extracorporeal membrane oxygenation (VA ECMO) is established in patients with cardiac arrest. This bypass can compensate for the functions of the heart and lungs until recovery of organ function. The benefit of ECPR compared to conventional resuscitation appears to be evident, especially after a prolonged resuscitation period; however, in three prospective randomized controlled studies an advantage has not yet been conclusively proven for widespread use in clinical routine. ECPR systems are complex and resource-intensive and should therefore be limited to specialized centers where sufficient numbers of patients are treated to ensure a high level of expertise in the teams.

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.

Pulmonary Protection from Left Ventricular Distension During Venoarterial Extracorporeal Membrane Oxygenation: Review and Management Algorithm

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in adults for refractory cardiogenic shock has risen exponentially during the prior decade. Although VA-ECMO provides cardiopulmonary support, it can alter left ventricular (LV) loading conditions leading to LV distension, which makes the lungs susceptible to congestion and promotes intracardiac thrombosis. These conditions can be alleviated by pharmacologic and mechanical unloading, but gaps in knowledge remain on optimal timing and methods of this approach. This review provides an overview of the epidemiology of VA-ECMO, describes pathophysiology and methods for monitoring and reducing LV loading and summarizes contemporary studies examining the association between LV unloading and adverse events. We offer a simple protocol for implementing LV unloading during VA-ECMO to provide pulmonary protection and improve outcomes.

Adjusted mortality of extracorporeal membrane oxygenation for acute myocardial infarction patients in cardiogenic shock

Cardiogenic shock (CS) is a common cause of death following acute myocardial infarction (MI). This study aimed to evaluate the adjusted mortality of venoarterial extracorporeal membrane oxygenation (VA-ECMO) with intra-aortic balloon counterpulsation (IABP) for patients with MI-CS. We included 300 MI patients selected from a multinational registry and categorized into VA-ECMO + IABP (N = 39) and no VA-ECMO (medical management ± IABP) (N = 261) groups. Both groups' 30-day and 1-year mortality were compared using the weighted Kaplan-Meier, propensity score, and inverse probability of treatment weighting methods. Adjusted incidences of 30-day (VA-ECMO + IABP vs No VA-ECMO, 77.7% vs 50.7; P = .083) and 1-year mortality (92.3% vs 84.8%; P = .223) along with propensity-adjusted and inverse probability of treatment weighting models in 30-day (hazard ratio [HR], 1.57; 95% confidence interval [CI], 0.92-2.77; P = .346 and HR, 1.44; 95% CI, 0.42-3.17; P = .452, respectively) and 1-year mortality (HR, 1.56; 95% CI, 0.95-2.56; P = .076 and HR, 1.33; 95% CI, 0.57-3.06; P = .51, respectively) did not differ between the groups. However, better survival benefit 30 days post-ECMO could be supposed (31.6% vs 83.4%; P = .022). Therefore, patients with MI-CS treated with IABP with additional VA-ECMO and those not supported with ECMO have comparable overall 30-day and 1-year mortality risks. However, VA-ECMO-supported survivors might have better long-term clinical outcomes.

Case report: Refractory cardiac arrest supported with veno-arterial-venous extracorporeal membrane oxygenation and left-ventricular Impella CP®-Physiological insights and pitfalls of ECMELLA

INTRODUCTION

To the best of our knowledge, this is the first case report which provides insights into patient-specific hemodynamics during veno-arterio-venous-extracorporeal membrane oxygenation (VAV ECMO) combined with a left-ventricular (LV) Impella® micro-axial pump for therapy-refractory cardiac arrest due to acute myocardial infarction, complicated by acute lung injury (ALI).

PATIENT PRESENTATION

A 54-year-old male patient presented with ST-segment elevation acute coronary syndrome complicated by out-of-hospital cardiac arrest with ventricular fibrillation upon arrival of the emergency medical service. As cardiac arrest was refractory to advanced cardiac life support, the patient was transferred to the Cardiac Arrest Center for immediate initiation of extracorporeal cardiopulmonary resuscitation (ECPR) with peripheral VA ECMO and emergency percutaneous coronary intervention using drug eluting stents in the right coronary artery. Due to LV distension and persistent asystole after coronary revascularization, an Impella® pump was inserted for LV unloading and additional hemodynamic support (i.e., "ECMELLA"). Despite successful unloading by ECMELLA, post-cardiac arrest treatment was further complicated by sudden differential hypoxemia of the upper body. This so called "Harlequin phenomenon" was explained by a new onset of ALI, necessitating escalation of VA ECMO to VAV ECMO, while maintaining Impella® support. Comprehensive monitoring as derived from the Impella® console allowed to illustrate patient-specific hemodynamics of cardiac unloading. Ultimately, the patient recovered and was discharged from the hospital 28 days after admission. 12 months after the index event the patient was enrolled in the ECPR Outpatient Care Program which revealed good recovery of neurologic functions while physical exercise capacities were impaired.

CONCLUSION

A combined mechanical circulatory support strategy may successfully be deployed in complex cases of severe cardio-circulatory and respiratory failure as occasionally encountered in clinical practice. While appreciating potential clinical benefits, it seems of utmost importance to closely monitor the physiological effects and related complications of such a multimodal approach to reach the most favorable outcome as illustrated in this case.