Timing and Strategy for Weaning From Venoarterial ECMO are Complex Issues

Echocardiographic parameters for weaning from extracorporeal membrane oxygenation-the role of longitudinal function and cardiac time intervals

AIMS

Limited data exist on echocardiographic predictors of weaning from veno-arterial extracorporeal membrane oxygenation (V-A ECMO). We aimed to test the performance of different echocardiographic indices to predict weaning from V-A ECMO and free survival after weaning.

METHODS AND RESULTS

Observational study including patients with cardiogenic shock submitted to V-AECMO. Echocardiography was performed after V-AECMO placement and daily during the weaning trial to assess cardiac recovery. Echocardiography data after V-A ECMO implantation and during the last weaning trial before V-A ECMO removal were analysed. Besides traditional parameters, total isovolumic time (t-IVT, a left ventricular performance index) and mitral annular plane systolic excursion (MAPSE) were also tested. Seventy-six patients were included. A greater ventricular velocity time integral (LVOT VTI) at baseline was associated with a five-fold increase in weaning success (P < 0.001) as MAPSE lateral >6.15 mm (P = 0.001) did. TAPSE and S' at tricuspid annulus showed an analogous association. During the weaning trial t-IVT, LVEF, MAPSE, LVOT VTI, and TAPSE all improved significantly (P < 0.001 for all). At regression analysis t-IVT <14.4 s/min (<0.001), LVOT VTI >12.3 cm (P < 0.001), MAPSE > 8.9 mm (P < 0.001), TAPSE > 16 mm (<0.001), and E/e' < 15.5 (P = 0.001) were associated with weaning success and free survival after weaning. LVEF did not predict the weaning success and survival at any time-point (P = 0.230).

CONCLUSION

Longitudinal function, t-IVT and native ejection, measured with LVOT VTI, are reliable parameters to predict weaning success in V-A ECMO whereas the LVEF, although dynamically changing during weaning trial, it is not.

Predictors of Mortality in Venoarterial Extracorporeal Membrane Oxygenation Regardless of Early Left Ventricular Unloading: A National Experience

OBJECTIVE

The use of an intra-aortic balloon pump (IABP) has been suggested to unload the left ventricle while on venoarterial extracorporeal membrane oxygenation (VA-ECMO) for cardiogenic shock (CS), leading to possibly improved in-hospital mortality. However, the predictors of mortality on dual mechanical circulatory support have not yet been evaluated, especially in real-world clinical settings. Therefore, a case-control study was conducted to determine the rate of all-cause mortality associated with VA-ECMO use regardless of left ventricular (LV) unloading, and with early LV unloading in the setting of CS, and to identify the predictors of mortality associated with VA-ECMO, with concurrent early LV unloading.

DESIGN

Retrospective observational case-control study.

SETTING

National tertiary cardiology center.

PARTICIPANTS

All patients with CS requiring VA-ECMO cannulation during the index admission between January 06, 2016, and January 0, 2022.

INTERVENTION

VA-ECMO with or without IABP MEASUREMENTS AND MAIN RESULTS: Patient- and disease-related characteristics associated with in-hospital 30-day mortality following VA-ECMO with and without IABP support were assessed using multivariate logistic regression. Results are presented as odds ratio (OR), and a p-value < 0.05 indicates statistical significance. A total of 110 patients were included. Most were male (90%) with a mean age of 53 ± 11 years. Around 67% were Asian. The majority of patients were admitted with ST-elevation myocardial infarction (87%), with 26% presenting with left main disease. In-hospital 30-day mortality occurred in 42.7% of those who received VA-ECMO support regardless of IABP use, while it was 46.9% among those receiving early LV unloading with IABP. Significant positive predictors of mortality with VA-ECMO regardless of IABP in CS were cardiopulmonary resuscitation (CPR) >20 minutes (adjusted OR 14.74, 95% confidence interval 2.02-107.41, p-value = 0.008), older age (ie, >55 years) and left main disease of more than 50% stenosis were associated with a fourfold increase in the odds of mortality while on VA-ECMO. Conversely, CPR >20 minutes (adjusted OR 12.45, 95% confidence interval 1.79-86.36, p-value = 0.011) was the only significant positive predictor of mortality with VA-ECMO and IABP.

CONCLUSION

The mortality rate in CS requiring VA-ECMO, regardless of IABP use, remains high. However, only one predictor (ie, prolonged CPR) was found to increase the likelihood of 30-day mortality with early LV unloading, suggesting that concomitant IABP use might minimize the effect of mortality predictors.

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.

Treatment time limit for successful weaning from veno-arterial extracorporeal membrane oxygenation in cardiogenic shock

AIMS

Knowing the upper time limit for successful weaning from temporary mechanical circulatory support in cardiogenic shock will help with decision-making regarding advanced heart failure (HF) therapy or considering withdrawal of care. The aim of this study was to investigate the association between the support duration and successful weaning from veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in patients with cardiogenic shock.

METHODS AND RESULTS

A retrospective single-centre cohort study was conducted between January 2013 and June 2023. It included 100 consecutive patients with cardiogenic shock who were treated with VA-ECMO. Patients with out-of-hospital cardiac arrest were excluded. The primary outcome was successful weaning from VA-ECMO (i.e., VA-ECMO decannulation and survival to discharge). The association between the length of support duration and the weaning success rate was analysed. Patients were divided into three groups according to ECMO support duration: Group A (≤7 days), Group B (8-14 days), and Group C (≥15 days). Multivariable logistic regression analysis was used to evaluate the impact of the length of support duration on successful weaning of VA-ECMO. The median age was 67 years, and 73% of study participants were male. The underlying aetiologies of cardiogenic shock were as follows: acute myocardial infarction, 50; fulminant myocarditis, 19; cardiomyopathy, 15; valvular heart disease, 8; and other, 8. Seventy-five patients (75%) were attempted to wean VA-ECMO, and 67 moved on to decannulation. In total, 43 (43%) patients were successfully weaned from VA-ECMO. The median length of ECMO support duration was 8 [3-15] days. Compared with those who underwent successful ECMO decannulation, those who did not had a significantly longer support duration of VA-ECMO (5 [3-9] days vs. 12 [3-22] days, P = 0.004). The weaning success rate was significantly higher in patients with short support duration; 58% (29/50), 40% (10/25), 16% (4/25) in Groups A, B, and C, respectively (P = 0.002). Overall, none of the patients supported for over 24 days (0/11) were successfully weaned from VA-ECMO. On multivariable logistic regression analysis, the length of support duration was independently associated with successful weaning after adjusting for age, sex, underlying aetiology, and left ventricular ejection fraction (odds ratio, 0.813 [per 3 days]; 95% confidence interval, 0.679-0.914; P = 0.025).

CONCLUSIONS

Long support duration of VA-ECMO was significantly associated with a low rate of successful weaning in patients with cardiogenic shock. Patients who require VA-ECMO for over 1 week should start considering advanced HF therapy or withdrawal of care.

VA-ECMO weaning strategy using adjusted pulse pressure by vasoactive inotropic score in AMI complicated by cardiogenic shock

AIMS

This study evaluated how well serial pulse pressure (PP) and PP adjusted by the vasoactive inotropic score (VIS) predicted venoarterial extracorporeal membrane oxygenation (VA-ECMO) weaning success and clinical outcomes in acute myocardial infarction complicated by cardiogenic shock (AMI-CS) patients.

METHODS AND RESULTS

A total of 213 patients with AMI-CS who received VA-ECMO between January 2010 and August 2021 were enrolled in the institutional ECMO registry. Serial PP and VIS were measured immediately, 12, 24, and 48 h after VA-ECMO insertion. PP adjusted by VIS was defined as PP/√VIS. The primary outcome was successful VA-ECMO weaning. Successful weaning from VA-ECMO was observed in 151 patients (70.9%). Immediately after VA-ECMO insertion, PP [successful vs. failed weaning, 26.0 (15.5-46.0) vs. 21.0 (12.5-33.0), P = 0.386] and PP/√VIS [11.1 (5.1-25.0) vs. 6.0 (3.1-14.2), P = 0.118] did not differ between the successful and failed weaning groups. Serial PP and PP adjusted by VIS at 12, 24, and 48 h after VA-ECMO insertion were significantly higher in patients with successful weaning than those with failed weaning [successful vs. failed weaning, 24.0 (4.0-38.0) vs. 12.5 (6.0-25.5), P = 0.007 for 12 h PP, and 10.1 (5.7-22.0) vs. 2.9 (1.7-5.9), P < 0.001 for 12 h PP/√VIS]. The 12 h PP/√VIS showed better discriminative function for successful weaning than 12 h PP alone [area under the curve (AUC) 0.80, 95% confidence interval (CI) 0.72-0.88, P < 0.001 vs. AUC 0.67, 95% CI 0.57-0.77, P = 0.002]. Patients with a low 12 h PP/√VIS (≤7) had higher rates of in-hospital mortality (44.4% vs. 19.8%, P < 0.001) and 6 month follow-up mortality (hazard ratio 2.41, 95% CI 1.49-3.90, P < 0.001) than those with a high 12 h PP/√VIS (>7).

CONCLUSIONS

PP adjusted by VIS taken 12 h following VA-ECMO initiation can predict weaning from VA-ECMO more successfully than PP alone, and its low value was associated with a higher risk of mortality in AMI-CS patients.

Assessment of cardiac load-responsiveness in veno-arterial extracorporeal life support: A case series

INTRODUCTION

Well-timed explant of veno-arterial extracorporeal life support (V-A ECLS) depends on adequate assessment of cardiac recovery. Often, evaluation of cardiac recovery consists of reducing support flow while visualizing cardiac response using transoesophageal echocardiography (TEE). This method, however, is time consuming and based on subjective findings. The dynamic filling index (DFI) may aid in the quantitative assessment of cardiac load-responsiveness. The dynamic filling index is based on the relationship of support flow and pump speed, which varies with varying hemodynamic conditions. This case series intends to investigate whether the DFI may support TEE in facilitating the assessment of cardiac load-responsiveness.

METHODS

Measurements for DFI-determination were performed in seven patients while simultaneously assessing ventricular function by measuring the aortic velocity time integral (VTI) using TEE. Measurements consisted of multiple consecutive transient speed manipulations (∼100 r/min) during weaning trials, both at full support and during cardiac reloading at reduced support.

RESULTS

The VTI increased between full and reduced support in six weaning trials. In five of these trials DFI decreased or remained equal, and in one case DFI increased. Of the three trials in which VTI decreased between full and reduced support, DFI increased in two cases and decreased in one case. Changes in DFI, however, are mostly smaller than the detection threshold of 0.4 mL/rotation.

CONCLUSION

Even though current level of accuracy of the parameter requires further investigation to increase reliability and possibly predictability, DFI seems likely to be a potential parameter in supporting TEE for the assessment of cardiac load-responsiveness.

Common mistakes and evidence-based approaches in goals-of-care conversations for seriously ill older adults in cardiac care unit

For older adults with serious, life-limiting illnesses near the end of life, clinicians frequently face difficult decisions about the medical care they provide because of clinical uncertainty. This difficulty is further complicated by unique challenges and medical advancements for patients with advanced heart diseases. In this article, we describe common mistakes encountered by clinicians when having goals-of-care conversations (e.g. conversations between clinicians and seriously ill patients/surrogates to discuss patient's values and goals for clinical care near the end of life.). Then, we delineate an evidence-based approach in goals-of-care conversations and highlight the unique challenges around decision-making in the cardiac intensive care unit.

Extracorporal Membrane Oxygenation in Massive Pulmonary Embolism

BACKGROUND

Massive pulmonary embolism (MPE) carries significant 30-day mortality risk, and a change in societal guidelines has promoted the increasing use of extracorporeal membrane oxygenation (ECMO) in the immediate management of MPE-associated cardiovascular shock. This narrative review examines the current status of ECMO in MPE.

METHODS

A literature review was performed from 1982 to 2022 searching for the terms "Pulmonary embolism" and "ECMO," and the search was refined by examining those publications that covered MPE.

RESULTS

In the patient with MPE, veno-arterial ECMO is now recommended as a bridge to interventional therapy. It can reliably decrease right ventricular overload, improve RV function, and allow hemodynamic stability and restoration of tissue oxygenation. The use of ECMO in MPE has been associated with lower mortality in registry reviews, but there has been no significant difference in outcomes between patients treated with and without ECMO in meta-analyses. Applying ECMO is also associated with substantial multisystem morbidity due to systemic inflammatory response, bleeding with coagulopathy, hemorrhagic stroke, renal dysfunction, and acute limb ischemia, which must be factored into the outcomes.

CONCLUSIONS

The application of ECMO in MPE should be combined with an aggressive interventional pulmonary interventional program and should strictly adhere to the current selection criteria.

Comparison of Conventional Methods with Pump-Controlled Retrograde Trial off for Weaning Adults with Cardiogenic Shock from Veno-Arterial Extracorporeal Membrane Oxygenation

Background

Pump-controlled retrograde trial off (PCRTO) is a safe, simple, and reversible method for weaning patients from veno-arterial extracorporeal membrane oxygenation (VA-ECMO). However, few studies have compared PCRTO to conventional weaning methods. This retrospective study aimed to compare PCRTO to non-PCRTO methods.

Methods

This study included patients who were weaned from VA-ECMO from January 2016 to December 2022 at our medical center. Demographic data, ECMO management, ECMO complications, survival to discharge, and cardiogenic shock after VA-ECMO weaning were compared between the 2 groups.

Results

Seventy patients who were weaned from VA-ECMO using PCRTO and 85 patients who were weaned with conventional methods were compared. Patient characteristics were not significantly different between the 2 groups. The rate of survival to discharge was significantly higher in the PCRTO group than in the non-PCRTO group (90% vs. 72%, p=0.01). The rates of freedom from all-cause mortality at 10, 30, and 50 days after weaning from ECMO were 75%, 55%, and 35% in the non-PCRTO group and 62%, 60%, and 58% in the PCRTO group, respectively (p=0.1). The incidence of cardiogenic shock after weaning from VA-ECMO was significantly higher in the non-PCRTO group (16% vs. 5%, p=0.04). In logistic regression analysis, PCRTO was a significant factor for survival to discharge (odds ratio, 2.42; 95% confidence interval, 1.29-5.28; p=0.02).

Conclusion

Compared to conventional methods, PCRTO is a feasible and reversible method, and it serves as a useful predictor of successful VA-ECMO weaning through a preload stress test.

Mechanical Circulatory Support Devices in Patients with High-Risk Pulmonary Embolism

Pulmonary embolism (PE) is a common acute cardiovascular condition. Within this review, we discuss the incidence, pathophysiology, and treatment options for patients with high-risk and massive pulmonary embolisms. In particular, we focus on the role of mechanical circulatory support devices and their possible therapeutic benefits in patients who are unresponsive to standard therapeutic options. Moreover, attention is given to device selection criteria, weaning protocols, and complication mitigation strategies. Finally, we underscore the necessity for more comprehensive studies to corroborate the benefits and safety of MCS devices in PE management.

Aortic arch blood flow measurements as a predictor of successful ECMO weaning in cardiogenic shock

Objective

Acute cardiogenic shock is a life-threatening condition with mortality rates of up to 50%. If conventional therapy fails, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) therapy has emerged to a promising alternative for temporary cardiac and respiratory support in specialized centers. However, it is only a bridge to recovery, final decision, heart transplantation or the permanent implantation of a left ventricular assist device. Therefore, the identification of the optimum weaning time point is challenging, and standardized weaning protocols are rare.

Methods

In this explorative pilot study, we evaluated the potential benefit of blood flow measurements in the aortic arch using an ultrasonic cardiac output monitor (USCOM) for the primary endpoint of successful VA-ECMO weaning. 12 patients under VA-ECMO therapy for acute cardiogenic shock and a hemodynamic condition which qualified for a stepwise weaning process were included in this study. Main exclusion criterion was the presence of additional venting therapy for left ventricular unloading, e.g. Impella. Statistical comparisons were performed using the Mann-Whitney test and corrected for multiple testing by the Holm-Sidak method.

Results

Peak velocity of flow in the aortic arch showed a positive correlation with weaning success independent of ECMO flow (weaning success vs. failure: 0.75 vs. 0.35 m/s (low ECMO support), p = 0.049), whereas we identified only a trend for mean pressure gradient, minute distance and stroke volume index.

Conclusion

We hypothesize, that USCOM might provide an additive benefit to conventional strategies in its ability to predict successful VA-ECMO weaning and prevent pulmonary congestion. Larger upcoming trials are required to address this relevant topic and provide standardized treatment protocols for optimized weaning in the future.

Outcomes following successful decannulation from extracorporeal life support for cardiogenic shock

OBJECTIVE

Although extracorporeal life support (ECLS) has increasingly been used for the treatment of patients with cardiogenic shock (CS), the outcomes of those successfully weaned from support remain poorly defined.

METHODS

Of 510 venoarterial ECLS CS patients at our institution between January 2015 and December 2020, 249 were decannulated and survived for 30 days or until discharge (ie, successfully weaned). Factors associated with survival to discharge were assessed and 1-year survival was described.

RESULTS

Of 510 eligible CS ECLS patients, 249 (48.8%) were successfully decannulated, 227 (44.5%) died during/following ECLS, and 34 (6.7%) were bridged to heart transplantation or a ventricular assist device. Patients with a primary graft dysfunction etiology of CS had a greater chance of successful decannulation (odds ratio [OR], 3.088; 95% CI, 1.1-8.671; P = .0323), whereas patients with ECLS during cardiopulmonary resuscitation had a reduced chance of successful decannulation (OR, 0.354; 95% CI, 0.17-0.735; P = .0054). Of successfully decannulated patients, 218 (87.6%) survived to hospital discharge and 31 (12.4%) died in the hospital. Acute myocardial infarction etiology (OR, 4.751; 95% CI, 1.623-13.902; P = .0044), preexisting chronic kidney disease (OR, 3.422; 95% CI, 1.374-8.52; P = .0082), and initiation of continuous renal replacement therapies (OR, 3.188; 95% CI, 1.291-7.871; P = .012) were significantly associated with in-hospital mortality despite successful decannulation. One-year survival in successfully decannulated patients surviving to hospital discharge was 95.0% and comparable to 1-year survival in patients who received a heart transplant or ventricular assist device.

CONCLUSIONS

Successful decannulation can be achieved in a significant proportion of patients treated with ECLS for CS but does not guarantee survival to hospital discharge. However, 1-year survival of hospital survivors remains high and is comparable to patients bridged to transplant or a ventricular assist device.

Patient-centered weaning from venoarterial extracorporeal membrane oxygenation: "A practice-oriented narrative review of literature"

Venoarterial extracorporeal membrane oxygenation (V-A ECMO) is increasingly used in cardiogenic shock for rapid stabilization and bridging towards recovery, long-term mechanical circulatory support or transplant. Although technological advances have instigated its widespread use, the complex, long-lasting ECMO care creates a significant strain on hospital staff and resources. Therefore, optimal clinical management including timely decisions on ECMO removal and further therapy are pivotal, yet require a well-structured weaning approach. Although dedicated guidelines are lacking, a variety of weaning protocols have distillated echocardiographic and hemodynamic predictors for successful weaning. Nevertheless, a strikingly high mortality up to 70% after initial successful weaning raises concerns about the validity of current weaning strategies. Here, we plead for a patient-tailored approach including a bailout strategy when weaning fails. This should account not only for left- but also right ventricular function and interdependence, as well as the temporal course of cardiac recovery in function of extracorporeal support. Patients with a high risk of weaning failure should be identified early, enabling timely transportation to an advanced heart failure center. This review summarizes predictors of successful weaning and discusses all relevant elements for a structured weaning approach with a central role for patient-specific clinical considerations and echocardiography.

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.

Feasibility of pump-controlled retrograde trial off in weaning from veno-arterial ECMO in adults-A single-center case series

BACKGROUND

Various strategies of weaning V-A ECMO have been described. PCRTO is a weaning technique which involves serial decremental pump revolutions until a retrograde flow from the arterial to venous ECMO cannula is achieved. It has been reported as a feasible weaning strategy in the pediatric population, but its application in adults has not been widely reported.

METHODS

This was a case series including all adult patients who underwent PCRTO during weaning from V-A ECMO at a tertiary ECMO center between January 2019 and July 2021. The primary end point was the successful weaning from V-A ECMO support.

RESULTS

A total of 57 runs of PCRTO in 36 patients were analyzed-45 (78.9%) of the trials were concluded successfully. The median retrograde blood flow rate during PCRTO was 0.6 ± 0.2 L/min, and the median duration of each PCRTO was 180 (120-240) min. Of the 35 patients who had at least one session of successful PCRTO, 31 (88.6%) were ultimately weaned from ECMO. There were no major complications from PCRTO including systemic or circuit thrombosis.

CONCLUSIONS

PCRTO is a feasible strategy for assessing readiness for weaning from V-A ECMO with a low risk of adverse events and high rate of predicting eventual successful ECMO decannulation. Further investigation including comparison with alternative weaning strategies in prospective studies is required to confirm the approach.

NEUROLOGIC IMPAIRMENT IN PATIENTS WITH EXTRACORPOREAL CARDIOPULMONARY RESUSCITATION SUPPORT: CLINICAL FEATURES AND LONG-TERM OUTCOMES

ABSTRACT

Introduction: The present study aimed to explore the clinical features and long-term outcomes associated with neurologic impairment in patients with cardiac arrest (CA) who received extracorporeal cardiopulmonary resuscitation (ECPR). Methods: A total of 37 adult CA patients who underwent venoarterial extracorporeal membrane oxygenation and were admitted to our department between January 2015 and February 2022 were divided according to neurologic impairment. Baseline and CPR- and ECMO-related characteristics were compared between the two groups. Long-term neurologic outcomes were collected via telephone follow-ups. Results: Twenty-four (64.9%) ECPR-supported patients developed neurologic impairments. The two groups differed significantly in median age (P = 0.026), proportion of intra-aortic balloon pump (IABP) support (P = 0.011), proportion of continuous renal replacement therapy (P = 0.025), and median serum creatinine (Cr) level (P = 0.012) pre-ECMO. The 28-day mortality (P = 0.001), hospital mortality (P = 0.003), median duration from CA to restoration of spontaneous circulation (P = 0.029), proportion of patients with nonpulsatile perfusion (NP) >12 hours (P = 0.040), and median ECMO duration (P = 0.047) were higher in the neurologic impairment group. In contrast, the group without neurologic impairment exhibited a longer median intensive care unit length of stay (P = 0.047), longer median hospital LOS (P = 0.031), and more successful ECMO weaning (P = 0.049). Moreover, NP >12 hours combined with IABP support (odds ratio [OR], 14.769; 95% confidence interval [CI], 1.417~153.889; P = 0.024) and serum Cr level (OR, 1.028; 95% CI, 1.001~1.056; P = 0.043) were independent risk factors for neurologic impairment. Furthermore, neurologic impairment was associated with significantly worse 90-day survival (hazards ratio, 4.218; 95% CI, 1.745~10.2; P = 0.0014). Conclusions: The incidence of neurologic impairment was higher in patients who received ECPR and was closely related to 28-day mortality and discharge survival. NP >12 hours combined with IABP support and serum Cr levels were independent risk factors for neurologic impairments in ECPR-supported patients. Neurologic impairment significantly adversely affected the long-term outcomes of ECPR-supported patients after discharge.

Parameters associated with successful weaning of veno-arterial extracorporeal membrane oxygenation: a systematic review

PURPOSE

Veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) can be used to restore organ perfusion in patients with cardiogenic shock until native heart recovery occurs. It may be challenging, however, to determine when patients can be weaned successfully from ECMO-surviving without requiring further mechanical support or heart transplant. We aimed to systematically review the medical literature to determine the biomarkers, hemodynamic and echocardiographic parameters associated with successful weaning of VA-ECMO in adults with cardiogenic shock and to present an evidence-based weaning algorithm incorporating key findings.

METHOD

We systematically searched PubMed, Embase, ProQuest, Google Scholars, Web of Science and the Grey literature for pertinent original research reports. We excluded studies limited to extracorporeal cardiopulmonary resuscitation (ECPR) as the neurological prognosis may significantly alter the decision-making process surrounding the device removal in this patient population. Studies with a mixed population of VA-ECMO for cardiogenic shock or cardiac arrest were included. We excluded studies limited to patients in which ECMO was only used as a bridge to VAD or heart transplant, as such patients are, by definition, never "successfully weaned." We used the Risk of Bias Assessment tool for Non-Randomized Studies. The study was registered on the International prospective register of systematic reviews (PROSPERO CRD42020178641).

RESULTS

We screened 14,578 records and included 47 that met our pre-specified criteria. Signs of lower initial severity of shock and myocardial injury, early recovery of systemic perfusion, left and right ventricular recovery, hemodynamic and echocardiographic stability during flow reduction trial and/or pump-controlled retrograde trial off predicted successful weaning. The most widely used parameter was the left ventricular outflow tract velocity time integral, an indicator of stroke volume. Most studies had a moderate or high risk of bias. Heterogeneity in methods, timing, and conditions of measurements precluded any meta-analysis.

CONCLUSIONS

In adult patients on VA-ECMO for cardiogenic shock, multiple biomarkers, hemodynamic and echocardiographic parameters may be used to track resolution of systemic hypoperfusion and myocardial recovery in order to identify patients that can be successfully weaned.

Echocardiographic Prediction of Successful Weaning From Venoarterial Extracorporeal Membrane Oxygenation

BACKGROUND

Weaning from venoarterial extracorporeal membrane oxygenation (VA-ECMO) support fails in 30% to 70% of patients.

OBJECTIVE

To explore the utility of echocardiographic parameters in predicting successful disconnection from VA-ECMO.

METHODS

Patients receiving VA-ECMO in a referral hospital were included. The relationships between echocardiographic parameters during the weaning trial and weaning success (survival > 24 hours after VA-ECMO explant and no death from cardiogenic shock, heart failure, or cardiac arrest during the hospital stay) and survival were evaluated.

RESULTS

Of 85 patients included, 61% had successful weaning. Parameters significantly related to weaning success were higher left ventricular ejection fraction (LVEF; 40% in patients with weaning success vs 30% in patients with weaning failure, P = .01), left ventricular outflow tract velocity time integral (15 cm vs 11 cm, P = .01), aortic valve opening in every cycle (98% vs 91% of patients, P = .01), and normal qualitative right ventricular function (60% vs 42% of patients, P = .02). The LVEF remained as an independent predictor of weaning success (hazard ratio, 0.938; 95% CI, 0.888-0.991; P = .02). An LVEF >33.4% was the optimal cutoff value to discriminate patients with successful weaning (area under the curve, 0.808; sensitivity, 93%; specificity, 72%) and was related to higher survival at discharge (60% vs 20%, P < .001).

CONCLUSION

Among weaning trial echocardiographic parameters, LVEF was the only independent predictor of successful VA-ECMO weaning. An LVEF >33.4% was the optimal cutoff value to discriminate patients with successful weaning and was related to final survival.

Predictors of weaning failure in case of VA ECMO implantation

The use of veno-arterial extracorporeal membrane oxygenation (VA ECMO) for the treatment of refractory cardiogenic shock has increased significantly. Nevertheless, early weaning may be advisable to reduce the potential for severe complications. Only a few studies focusing on ECMO weaning predictors are currently available. Our objective was to evaluate factors that may help predict failure during VA ECMO weaning. We included 57 patients on VA ECMO support previously considered suitable for weaning based on specific criteria. Clinical, haemato-chemical and echocardiographic assessment was considered before and after a "weaning test" (ECMO flow < 2 L/min for at least 60 min). ECMO removal was left to the discretion of the medical team blinded to the results. Weaning failure was defined as a patient who died or required a new VA ECMO, heart transplant or LVAD 30 days after ECMO removal. Thirty-six patients (63.2%) were successfully weaned off VA ECMO, of whom 31 (54.4%) after the first weaning test. In case of first test failure, 3 out of 7 patients could be weaned after a 2nd test and 3 out of 4 patients after a 3rd test. Pre-existing ischemic heart disease (OR 9.6 [1.1-83]), pre-test left ventricular ejection fraction (LVEF) ≤ 25% and/or post-test LVEF ≤ 40% (OR 11 [0.98-115]), post-test systolic blood pressure ≤ 120 mmHg (OR 33 [3-385]), or length of ECMO support > 7 days (OR 24 [2-269]) were predictors of weaning failure. The VA ECMO weaning test failed in less than 40% of patients considered suitable for weaning. Clinical and echocardiographic criteria, which are easily accessible by a non-expert intensivist, may help increase the probability of successful weaning.

Sensitivity of ventricular systolic function to afterload during veno-arterial extracorporeal membrane oxygenation

AIMS

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) increases afterload to the injured heart and may hinder myocardial recovery. We aimed to compare the sensitivity of left ventricular (LV) systolic function to the afterload effects of peripheral V-A ECMO during the acute and delayed stages of acute myocardial dysfunction.

METHODS AND RESULTS

A total of 46 adult patients who were supported by peripheral V-A ECMO between April 2019 and June 2021 were analysed. Serial cardiac performance parameters were measured by transthoracic echocardiography (TTE) on mean day 1 ± 1 of V-A ECMO initiation (n = 45, 'acute phase') and mean day 4 ± 2 of V-A ECMO initiation (n = 36, 'delayed phase'). Measurements were obtained at 100%, 120%, and 50% of ECMO target blood flow (TBF). LV global longitudinal strain (GLS) significantly improved from -6.1 (-8.9 to -4.0)% during 120% TBF to -8.8 (-11.5 to -6.0)% during 50% TBF (P < 0.001). The sensitivity of LV GLS to changes in ECMO flow was significantly greater in the acute phase of myocardial injury compared with the delayed phase [median (IQR) percentage change: 72.7 (26.8-100.0)% vs. 22.5 (14.9-43.8)%, P < 0.001]. Findings from other echocardiographic parameters including LV ejection fraction [43.0 (29.1-56.8)% vs. 22.8 (9.2-42.2)%, P = 0.012] and LV outflow tract velocity-time integral [45.8 (18.6-58.7)% vs. 24.2 (12.6-34.0)%, P = 0.001] were similar. A total of 24 (52.2%) patients were weaned off ECMO successfully.

CONCLUSIONS

We demonstrated that LV systolic function was significantly more sensitive to the afterload effects of V-A ECMO during the acute stage of myocardial dysfunction compared with the delayed phase. Understanding the evolution of the heart-ECMO interaction over the course of acute myocardial dysfunction informs the clinical utility of echocardiographic assessment in patients on V-A ECMO.

Early Levosimendan Administration Improved Weaning Success Rate in Extracorporeal Membrane Oxygenation in Patients With Cardiogenic Shock

Background

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been increasingly used in patients with refractory cardiogenic shock (CS) or out-of-hospital cardiac arrest. It is difficult to perform VA-ECMO weaning, which may cause circulatory failure and death. Levosimendan is an effective inotropic agent used to maintain cardiac output, has a long-lasting effect, and may have the potential benefit for VA-ECMO weaning. The study aimed to explore the relationship between the early use of levosimendan and the rate of VA-ECMO weaning failure in patients on VA-ECMO support for circulatory failure.

Methods

All patients who underwent VA-ECMO in our hospital for CS between January 2017 and December 2020 were recruited in this cohort study and divided into two groups: without and with levosimendan use. Levosimendan was used as an add-on to other inotropic agents as early as possible after VA-ECMO setting. The primary endpoint was VA-ECMO weaning success, which was defined as survival without events for 24 h after VA-ECMO withdrawl. The secondary outcomes were cardiovascular and all-cause mortality at the 30-day and 180-day follow-up periods post-VA-ECMO initialization.

Results

A total of 159 patients were recruited for our study; 113 patients were enrolled in the without levosimendan-use group and 46 patients were enrolled in the levosimendan-use group. In levosimendan-use group, the patients received levosimendan infusion within 24 h after VA-ECMO initialization. Similar hemodynamic parameters were noted between the two groups. Poorer left ventricular ejection fraction and a higher prevalence of intra-aortic balloon pumping were observed in the levosimendan group. An improved weaning rate (without vs. with: 48.7 vs. 82.6%; p < 0.001), lower in-hospital mortality rate (without vs. with: 68.1 vs. 43.5%; p = 0.007), and 180-day cardiovascular mortality (without vs. with: 75.3 vs. 43.2%; p < 0.001) were also noted. Patients administered with levosimendan also presented a lower rate of 30-day (without vs. with: 75.3 vs. 41.3%; p = 0.034) and 180-day (without vs. with: 77.0 vs. 43.2%; p < 0.001) all-cause mortality.

Conclusion

Early levosimendan administration may contribute to increasing the success rate of VA-ECMO weaning and may help to decrease CV and all-cause mortality.

Early Blood Pressure Variables Associated With Improved Outcomes in VA-ECLS: The ELSO Registry Analysis

BACKGROUND

As utilization of veno-arterial extracorporeal life support (VA-ECLS) in treatment of cardiogenic shock (CS) continues to expand, clinical variables that guide clinicians in early recognition of myocardial recovery and therefore, improved survival, after VA-ECLS are critical. There remains a paucity of literature on early postinitiation blood pressure measurements that predict improved outcomes.

OBJECTIVES

The objective of this study is to help identify early blood pressure variables associated with improved outcomes in VA-ECLS.

METHODS

The authors queried the ELSO (Extracorporeal Life Support Organization) registry for cardiogenic shock patients treated with VA-ECLS or venovenous arterial ECLS between 2009 and 2020. Their inclusion criteria included treatment with VA-ECLS or venovenous arterial ECLS; absence of pre-existing durable right, left, or biventricular assist devices; no pre-ECLS cardiac arrest; and no surgical or percutaneously placed left ventricular venting devices during their ECLS runs. Their primary outcome of interest was the survival to discharge during index hospitalization.

RESULTS

A total of 2,400 CS patients met the authors' inclusion criteria and had complete documentation of blood pressures. Actual mortality during index hospitalization in their cohort was 49.5% and survivors were younger and more likely to be Caucasian, intubated for >30 hours pre-ECLS initiation, and had a favorable baseline SAVE (Survival After Veno-arterial ECMO) score (P < 0.05 for all). Multivariable regression analyses adjusting for SAVE score, age, ECLS flow at 4 hours, and race showed that every 10-mm Hg increase in baseline systolic blood pressure (HR: 0.92 [95% CI: 0.89-0.95]; P < 0.001), and baseline pulse pressure (HR: 0.88 [95% CI: 0.84-0.91]; P < 0.001) at 24 hours was associated with a statistically significant reduction in mortality.

CONCLUSIONS

Early (within 24 hours) improvements in pulse pressure and systolic blood pressure from baseline are associated with improved survival to discharge among CS patients treated with VA-ECLS.

Monitoring during extracorporeal membrane oxygenation

PURPOSE OF REVIEW

Extracorporeal membrane oxygenation (ECMO) offers advanced mechanical support to patients with severe acute respiratory and/or cardiac failure. Ensuring an adequate therapeutic approach as well as prevention of ECMO-associated complications, by means of timely liberation, forms an essential part of standard ECMO care and is only achievable through continuous monitoring and evaluation. This review focus on the cardiorespiratory monitoring tools that can be used to assess and titrate adequacy of ECMO therapy; as well as methods to assess readiness to wean and/or discontinue ECMO support.

RECENT FINDINGS

Surrogates of tissue perfusion and near infrared spectroscopy are not standards of care but may provide useful information in select patients. Echocardiography allows to determine cannulas position, evaluate cardiac structures, and function, and diagnose complications. Respiratory monitoring is mandatory to achieve lung protective ventilation and identify early lung recovery, surrogate measurements of respiratory effort and ECMO derived parameters are invaluable in optimally managing ECMO patients.

SUMMARY

Novel applications of existing monitoring modalities alongside evolving technological advances enable the advanced monitoring required for safe delivery of ECMO. Liberation trials are necessary to minimize time sensitive ECMO related complications; however, these have yet to be standardized.

Assessment of cardiac recovery in patients supported with venoarterial extracorporeal membrane oxygenation

Aims

Venoarterial extracorporeal membrane oxygenation (VA‐ECMO) is increasingly being used to support patients in cardiogenic shock (CS). Early determination of disposition is paramount, as longer durations of support have been associated with worse outcomes. We describe a stepwise, bedside weaning protocol to assess cardiopulmonary recovery during VA‐ECMO.

Methods and results

Over 1 year, we considered all patients on VA‐ECMO for CS for the Weaning Protocol (WP) at our centre. During the WP, patients had invasive haemodynamic monitoring, echocardiography, and blood gas analysis while flow was reduced in 1 LPM decrements. Ultimately, the circuit was clamped for 30 min, and final measures were taken. Patients were described as having durable recovery (DR) if they were free of pharmacological and mechanical support at 30 days post‐decannulation. Over 12 months, 34 patients had VA‐ECMO for CS. Fourteen patients were eligible for the WP at 4–12 days. Ten patients tolerated full flow reduction and were successfully decannulated. Twenty‐four per cent of the entire cohort demonstrated DR with no adverse events during the WP. Patients with DR had significantly higher ejection fraction, cardiac index, and smaller left ventricular size at lowest flow during the WP.

Conclusions

We describe a safe, stepwise, bedside weaning protocol to assess cardiac recovery during VA‐ECMO. Early identification of patients more likely to recover may improve outcomes during ECMO support.

Echocardiography for extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) provides advanced cardiopulmonary life support for patients in cardiac and/or respiratory failure. Echocardiography provides essential diagnostic and anatomic information prior to ECMO initiation, allows for safe and efficient ECMO cannula positioning, guides optimization of flow, provides a modality for rapid troubleshooting and patient evaluation, and facilitates decision-making for eventual weaning of ECMO support. Currently, guidelines for echocardiographic assessment in this clinical context are lacking. In this review, we provide an overview of echocardiographic considerations for advanced imagers involved in the care of these complex patients. We focus predominately on new cannulas and complex cannulation techniques, including a special focus on double lumen cannulas and a section discussing indirect left ventricular venting. Echocardiography is tremendously valuable in providing optimal care in these challenging clinical situations. It is imperative for imaging physicians to understand the pertinent anatomic considerations, the often complicated physiological and hemodynamic context, and the limitations of the imaging modality.

Bivalirudin versus Heparin in Pediatric and Adult Patients on Extracorporeal Membrane Oxygenation: A Meta-analysis

AIMS

Unfractionated heparin (UFH) has been the primary anticoagulant of choice on extracorporeal membrane oxygenation (ECMO). However, it is debatable whether bivalirudin (BIV), a direct thrombin inhibitor, may be considered a better alternative anticoagulant option.

METHODS

We searched Embase, Pubmed, Cochrane library, Clinicaltrials.gov, CNKI, and Wanfang databases up to June 15, 2021. Randomized controlled trials (RCTs) and observational studies were considered eligible for inclusion. Random-effects meta-analyses, including subgroup analyses, were conducted.

RESULTS

A total of 9 studies containing 994 patients were enrolled. All articles were retrospective cohort studies. Compared with UFH, BIV was associated with lower risks of major bleeding (risk ratio [RR]: 0.32, 95% confidence interval [CI] 0.22-0.49), ECMO in-circuit thrombosis (RR: 0.57, 95% CI 0.43-0.74), stroke (RR: 0.52, 95% CI 0.29-0.95), in-hospital mortality (RR: 0.82, 95% CI 0.69-0.99) and higher rates of survival to ECMO decannulation (RR: 1.18, 95% CI 1.03-1.34). Pooled risk estimates did not show a significant association with clinical thrombotic events (RR: 0.69, 95% CI 0.45-1.07). Moreover, BIV was associated with a lower risk of ECMO in-circuit thrombosis and in-hospital mortality in the adult subgroup but not in the pediatric subgroup. However, leave-one-out sensitivity analyses indicated that the results of stroke, survival to ECMO decannulation and in-hospital mortality should be interpreted with caution.

CONCLUSIONS

BIV appears to be a potential alternative to UFH in pediatric and adult patients requiring ECMO.

Levosimendan in intensive care and emergency medicine: literature update and expert recommendations for optimal efficacy and safety

The inodilator levosimendan, in clinical use for over two decades, has been the subject of extensive clinical and experimental evaluation in various clinical settings beyond its principal indication in the management of acutely decompensated chronic heart failure. Critical care and emergency medicine applications for levosimendan have included postoperative settings, septic shock, and cardiogenic shock. As the experience in these areas continues to expand, an international task force of experts from 15 countries (Austria, Belgium, China, Croatia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Spain, Sweden, Switzerland, and the USA) reviewed and appraised the latest additions to the database of levosimendan use in critical care, considering all the clinical studies, meta-analyses, and guidelines published from September 2019 to November 2021. Overall, the authors of this opinion paper give levosimendan a "should be considered" recommendation in critical care and emergency medicine settings, with different levels of evidence in postoperative settings, septic shock, weaning from mechanical ventilation, weaning from veno-arterial extracorporeal membrane oxygenation, cardiogenic shock, and Takotsubo syndrome, in all cases when an inodilator is needed to restore acute severely reduced left or right ventricular ejection fraction and overall haemodynamic balance, and also in the presence of renal dysfunction/failure.

Platelet Phenotype and Function Changes With Increasing Duration of Extracorporeal Membrane Oxygenation

OBJECTIVES

To investigate platelet pathophysiology associated with pediatric extracorporeal membrane oxygenation (ECMO).

DESIGN

Prospective observational study of neonatal and pediatric ECMO patients from September 1, 2016, to December 31, 2019.

SETTING

The PICU in a large tertiary referral pediatric ECMO center.

PATIENTS

Eighty-seven neonates and children (< 18 yr) supported by ECMO.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Arterial blood samples were collected on days 1, 2, and 5 of ECMO and were analyzed by whole blood flow cytometry. Corresponding clinical data for each patient was also recorded. A total of 87 patients were recruited (median age, 65 d; interquartile range [IQR], 7 d to 4 yr). The median duration of ECMO was 5 days (IQR, 3-8 d) with a median length of stay in PICU and hospital of 18 days (IQR, 10-29 d) and 35 days (IQR, 19-75 d), respectively. Forty-two patients (48%) had at least one major bleed according to a priori determined definitions, and 12 patients (14%) had at least one thrombotic event during ECMO. Platelet fibrinogen receptor expression decreased (median fluorescence intensity [MFI], 29,256 vs 26,544; p = 0.0005), while von Willebrand Factor expression increased (MFI: 7,620 vs 8,829; p = 0.0459) from day 2 to day 5 of ECMO. Platelet response to agonist, Thrombin Receptor Activator Peptide 6, also decreased from day 2 to day 5 of ECMO, as measured by binding with anti-P-selectin, PAC-1 (binds activated GPIIb/IIIa), and anti-CD63 monoclonal antibodies (P-selectin area under the curve [AUC]: 63.46 vs 42.82, respectively, p = 0.0022; PAC-1 AUC: 93.75 vs 74.46, p = 0.0191; CD63 AUC: 55.69 vs 41.76, p = 0.0020).

CONCLUSIONS

The loss of platelet response over time may contribute to bleeding during ECMO. These novel insights may be useful in understanding mechanisms of bleeding in pediatric ECMO and monitoring platelet markers clinically could allow for prediction or early detection of bleeding and thrombosis.

Intraoperative Management of Adult Patients on Extracorporeal Membrane Oxygenation: An Expert Consensus Statement From the Society of Cardiovascular Anesthesiologists-Part II, Intraoperative Management and Troubleshooting

In the second part of the Society of Cardiovascular Anesthesiologists Extracorporeal Membrane Oxygenation (ECMO) working group expert consensus statement, venoarterial (VA) and venovenous (VV) ECMO management and troubleshooting in the operating room are discussed. Expert consensus statements are provided about intraoperative monitoring, anesthetic drug dosing, and management of intraoperative problems in VA and VV ECMO patients.

Extracorporeal Life Support for Cardiac Arrest and Cardiogenic Shock

The rising incidence and recognition of cardiogenic shock has led to an increase in the use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). As clinical experience with this therapy has increased, there has also been a rapid growth in the body of observational and randomized data describing the clinical and logistical considerations required to institute a VA-ECMO program with successful clinical outcomes. The aim of this review is to summarize this contemporary data in the context of four key themes that pertain to VA-ECMO programs: the principles of patient selection; basic hemodynamic and technical principles underlying VA-ECMO; contraindications to VA-ECMO therapy; and common complications and intensive care considerations that are encountered in the setting of VA-ECMO therapy.

SEDAR/SECCE ECMO management consensus document

ECMO is an extracorporeal cardiorespiratory support system whose use has been increased in the last decade. Respiratory failure, postcardiotomy shock, and lung or heart primary graft failure may require the use of cardiorespiratory mechanical assistance. In this scenario perioperative medical and surgical management is crucial. Despite the evolution of technology in the area of extracorporeal support, morbidity and mortality of these patients continues to be high, and therefore the indication as well as the ECMO removal should be established within a multidisciplinary team with expertise in the area. This consensus document aims to unify medical knowledge and provides recommendations based on both the recent bibliography and the main national ECMO implantation centres experience with the goal of improving comprehensive patient care.

How to Turn It Down: The Evidence and Opinions Behind Adult Venoarterial Extracorporeal Membrane Oxygenation Weaning

Adequate and durable recovery in patients supported with venoarterial (VA) extracorporeal membrane oxygenation (ECMO) can be challenging to predict. Extracorporeal membrane oxygenation weaning is the process by which the ECMO flows are decreased to assess if a patient is ready for decannulation. The optimal strategies for deciding who to wean and how to wean VA ECMO remain undefined. A retrospective literature review was performed to understand the evidence supporting current practices in ECMO weaning and in particular patient selection and methods. Most published work and expert opinions agree that once the underlying process has resolved, the minimum required physiologic parameters for weaning from ECMO include: hemodynamic stability and cardiac pulsatility, adequate lung function to support oxygenation and ventilation, and evidence of recovered end organ function. Echocardiography is universally used to assess cardiac function during the weaning process. Currently, there is no consensus regarding who is eligible to wean or how to wean ECMO in adults. We have reviewed the literature to summarize the evidence and expert opinions behind VA ECMO weaning, and give an example of the protocol used at our center. We believe this protocol optimizes patient selection for weaning and helps to predict successful decannulation.

A Pragmatic Approach to Weaning Temporary Mechanical Circulatory Support: A State-of-the-Art Review

Temporary mechanical circulatory support (TMCS) provides short-term support to patients with or at risk of refractory cardiogenic shock. Although indications, contraindications, and complications of TMCS may guide device selection, optimal strategies for device weaning and explant remain poorly defined. Under the revised adult heart allocation policy implemented by the United Nations for Organ Sharing in October 2018, rejustification of heart transplant listing status includes demonstrating TMCS dependency with attempted device wean trials. However, standardized device-specific weaning and explant protocols have not been proposed or evaluated. This review highlights when to use percutaneous TMCS in cardiogenic shock, with a focus on weaning and explant considerations. Terminology for important concepts that guide device escalation, de-escalation, and explantation have been defined. Clinical, hemodynamic, metabolic, and imaging features have been defined, which can guide a tailored approach to TMCS weaning and explant based on the approach used at the Cleveland Clinic. A narrative review of published studies that have reported TMCS weaning protocols and survey results of member centers from CS-MCS working group centers is also provided. Future research is needed to better understand optimal timing and implementation of standardized protocols to achieve successful TMCS weaning and explant.

A systematic approach to weaning from extracorporeal membrane oxygenation in patients with refractory cardiac failure

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is commonly used to provide haemodynamic support for patients with severe cardiac failure. However, timing ECMO weaning remains challenging. We aimed to examine if an integrative weaning approach based on predefined haemodynamic, respiratory and echocardiographic criteria is associated with successful weaning.

METHODS

All patients weaned from ECMO between April 2017 and April 2019 at Aarhus University Hospital, Denmark, were consecutively enrolled. Predefined haemodynamic, respiratory and echocardiographic criteria were assessed before and during ECMO flow reduction. A weaning attempt was commenced in haemodynamic stable patients and patients remaining stable at minimal flow were weaned from ECMO. Comparisons were made between patients who met the criteria for weaning at first attempt and patients who did not meet these criteria. Patients completing a full weaning attempt with no further need for mechanical support within 24 h were defined as successfully weaned.

RESULTS

A total of 38 patients were included in the study, of whom 26 (68%) patients met the criteria for weaning. Among these patients, 25 (96%) could be successfully weaned. Successfully weaned patients were younger and had less need for inotropic support and ECMO duration was shorter. Fulfilling the weaning criteria was associated with successful weaning and both favourable 30-d survival and survival to discharge.

CONCLUSION

An integrative weaning approach based on haemodynamic, respiratory and echocardiographic criteria may strengthen the clinical decision process in predicting successful weaning in patients receiving ECMO for refractory cardiac failure.

Levosimendan in venoarterial ECMO weaning. Rational and design of a randomized double blind multicentre trial

AIMS

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly being used in circulatory failure. The main indications are cardiogenic shock, post-cardiotomy cardiac failure, and refractory cardiac arrest. However, VA-ECMO weaning is particularly challenging, and weaning failure is reported to be as high as 50%, with increased related mortality. Levosimendan is a novel long acting effect inodilator used in cardiogenic shock and terminal heart failure decompensation. Levosimendan use in VA-ECMO patients seems to reduce weaning failure regardless of the initial aetiology and to reduce mortality when administrated early after VA-ECMO initiation. However, studies are limited to retrospective analyses and reported case series. The aim of the WEANILEVO trial is to evaluate whether administration of levosimendan before VA-ECMO weaning is associated with a reduced rates of weaning failure and recourse to other temporary circulatory support.

METHODS AND RESULTS

WEANILEVO is a randomized, prospective, multicentre, double-blind, parallel-group, controlled trial. One hundred eighty patients will be enrolled if they had acute circulatory heart failure treated with VA-ECMO and for whom weaning is expected within 48 h. The study drugs are either levosimendan (0.2 μg/kg/min for 24 h) or a placebo. The primary endpoint of the trial is the absence of VA-ECMO weaning, recourse to another VA-ECMO, or other temporary circulatory assistance or death within 7 days of VA-ECMO weaning.

CONCLUSIONS

Levosimendan use in VA-ECMO appears to be beneficial for reducing weaning failure and mortality. The results of WEANILEVO should significantly influence decisions regarding the use of levosimendan for VA-ECMO weaning.

Liberation From Venoarterial Extracorporeal Membrane Oxygenation: A Review

Venoarterial extracorporeal membrane oxygenation may be used for circulatory support in cardiogenic shock as a bridge to recovery, a bridge to a ventricular assist device (VAD), or a bridge to transplant. While the determination of potential exit strategies is essential before cannulation, the final determination of a patient's options may change, in part, through their in-hospital clinical course. We propose that liberation from venoarterial extracorporeal membrane oxygenation should be conceptualized as a process of discovery in the assessment of a patient's underlying clinical status and a key driver of further clinical decision-making. A trial of liberation from support should be considered when the goals of the weaning trial are well-defined and, ideally, in the absence of potentially confounding clinical factors. In this review, we will discuss readiness to wean criteria from venoarterial extracorporeal membrane oxygenation, as well as specific clinical, biochemical, and echocardiographic parameters that may prove useful in determining weaning timing and revealing the patient's underlying hemodynamic status and prognosis. The role of various cannula configurations, support devices, and pharmacological adjuncts will also be discussed. Finally, we highlight current gaps in evidence and suggest areas of future research.

Overview of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) Support for the Management of Cardiogenic Shock

Cardiogenic shock accounts for ~100,000 annual hospital admissions in the United States. Despite improvements in medical management strategies, in-hospital mortality remains unacceptably high. Multiple mechanical circulatory support devices have been developed with the aim to provide hemodynamic support and to improve outcomes in this population. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is the most advanced temporary life support system that is unique in that it provides immediate and complete hemodynamic support as well as concomitant gas exchange. In this review, we discuss the fundamental concepts and hemodynamic aspects of VA-ECMO support in patients with cardiogenic shock of various etiologies. In addition, we review the common indications, contraindications and complications associated with VA-ECMO use.

Cardiac intensive care management of high-risk percutaneous coronary intervention using the venoarterial ECMO support

The emerging concept of high-risk percutaneous coronary intervention (HR-PCI) has required the adoption of a multidisciplinary team approach. Venoarterial ECMO (VA-ECMO) has been introduced as a temporary mechanical circulatory support (MCS) for HR-PCI patients in order to provide an adequate systemic perfusion during the procedure. Both patient's complexity and technological evolutions have catalyzed the development of critical care cardiology; however, ECMO therapy faces several challenges. Indeed, the management of patients on ECMO remains complex; moreover, the lack of specific recommendation for HR-PCI patients further complicates the management of these patients. In this narrative review, we give a reappraisal for the management of HR-PCI patients supported with VA-ECMO according to the available data published in current literature.

Neurological Complications of Veno-Arterial Extracorporeal Membrane Oxygenation: A Retrospective Case-Control Study

Background: To explore the epidemiology, clinical features, risk indicators, and long-term outcomes of neurological complications caused by veno-arterial extracorporeal membrane oxygenation (V-A ECMO).

Methods: We retrospectively analyzed 60 adult patients who underwent V-A ECMO support in our unit from February 2012 to August 2020. These patients were separated into the neurological complications group (NC group) and the non-neurological complications group (nNC group). The differences in basic data and ECMO data between the two groups were compared. The data of long-term neurological prognosis were collected by telephone follow-up.

Results: Thirty-nine patients (65.0%) had neurological complications. There were significant differences between the two groups in terms of median age, hypertension, median blood urea nitrogen, median troponin I (TNI), median lactic acid, pre-ECMO percutaneous coronary intervention, continuous renal replacement therapy (CRRT), median Sequential Organ Failure Assessment score, median Acute Physiology and Chronic Health Evaluation II score, median peak inspiratory pressure, median positive end expiratory pressure, and median fresh frozen plasma (P < 0.05). The median Intensive Care Unit length of stay (ICU LOS), 28-day mortality, median post-ECMO vasoactive inotropic score, non-pulsate perfusion (NP), and median ECMO duration of the NC group were significantly higher than those of the nNC group (P < 0.05). Furthermore, multiple logistic regression analysis revealed that TNI (P = 0.043), CRRT (P = 0.047), and continuous NP > 12 h (P = 0.043) were independent risk indicators for neurological complications in patients undergoing ECMO. Forty-four patients (73.3%) survived after discharge, and 38 patients (63.3%) had Cerebral Performance Category score of 1–2. And there were significant differences between the two groups in long-term neurological outcomes after discharge for 6 months (P < 0.05).

Conclusion: The incidence of neurological complications was higher in patients undergoing V-A ECMO and was closely related to adverse outcomes (including ICU LOS and 28-day mortality). TNI, CRRT, and continuous NP > 12 h were independent risk indicators for predicting neurological complications in ECMO supporting patients. And the neurological complications of patients during ECMO support had significant adverse effect on long-term surviving and neurological outcomes of patients after discharge for 6 months.

Analysis of the 2020 EACTS/ELSO/STS/AATS Expert Guidelines on the Management of Adult Postcardiotomy Extracorporeal Life Support

Extracorporeal life support (ECLS), also known as extracorporeal membrane oxygenation (ECMO), increasingly is used in postcardiotomy (PC) shock to facilitate a bridge to sustained recovery, long-term mechanical support, or heart transplantation. Given increasing prevalence and complexity of PC-ECLS, a joint expert consensus guideline was created in 2020 for management of adult PC-ECLS by the European Association for Cardio-Thoracic Surgery (EACTS), the Extracorporeal Life Support Organization (ELSO), the Society of Thoracic Surgeons (STS), and the American Association of Thoracic Surgery (AATS). The aim of this analysis was to comprehensively review the expert consensus guidelines, with particular emphasis on PC-ECLS candidacy, timing, cannula configuration, left ventricular distention, anticoagulation, ECLS weaning, and intensive care unit complications. This analysis finds the expert consensus guideline to be timely, pertinent, and clinically valuable, although there remains the need for larger clinical trials to codify best practices.

Estimating cardiac output based on gas exchange during veno-arterial extracorporeal membrane oxygenation in a simulation study using paediatric oxygenators

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A lung circuit (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙_Lung) and an ECMO circuit (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙_ECMO) with oxygenators for CO₂ removal (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.CO₂) and O₂ uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.O₂) simulated the setting of VA-ECMO with varying ventilation/perfusion (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V./\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙) ratios and shunt. A metabolic chamber with a CO₂/N₂ blend simulated \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.CO₂ and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.O₂. \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙_Lung was estimated with a modified Fick principle: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙_Lung = \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙_ECMO × (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V. CO₂ or \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.O_2Lung)/(\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.CO₂ or \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.O_2ECMO). A normalization procedure corrected \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.CO₂ values for a \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V./\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙ of 1. Method agreement was evaluated by Bland–Altman analysis. Calculated \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙_Lung using gaseous \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.CO₂ and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.O₂ correlated well with measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙_Lung with a bias of 103 ml/min [− 268 to 185] ml/min; Limits of Agreement: − 306 ml/min [− 241 to − 877 ml/min] to 512 ml/min [447 to 610 ml/min], r² 0.85 [0.79–0.88]). Blood measurements of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.CO₂ showed an increased bias (− 260 ml/min [− 1503 to 982] ml/min), clinically not applicable. Shunt and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V./\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙ mismatch decreased the agreement of methods significantly. This in-vitro simulation shows that \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.CO₂ and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathop {\text{V}}\limits^{.}$$\end{document}V.O₂ in steady-state conditions allow for clinically applicable calculations of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{Q}}}$$\end{document}Q˙_Lung during VA-ECMO therapy.

Prevention and treatment of pulmonary congestion in patients undergoing venoarterial extracorporeal membrane oxygenation for cardiogenic shock

Cardiogenic shock is still a major driver of mortality on intensive care units and complicates ∼10% of acute coronary syndromes with contemporary mortality rates up to 50%. In the meantime, percutaneous circulatory support devices, in particular venoarterial extracorporeal membrane oxygenation (VA-ECMO), have emerged as an established salvage intervention for patients in cardiogenic shock. Venoarterial extracorporeal membrane oxygenation provides temporary circulatory support until other treatments are effective and enables recovery or serves as a bridge to ventricular assist devices, heart transplantation, or decision-making. In this critical care perspective, we provide a concise overview of VA-ECMO utilization in cardiogenic shock, considering rationale, critical care management, as well as weaning aspects. We supplement previous literature by focusing on therapeutic issues related to the vicious circle of retrograde aortic VA-ECMO flow, increased left ventricular (LV) afterload, insufficient LV unloading, and severe pulmonary congestion limiting prognosis in a relevant proportion of patients receiving VA-ECMO treatment. We will outline different modifications in percutaneous mechanical circulatory support to meet this challenge. Besides a strategy of running ECMO at lowest possible flow rates, novel therapeutic options including the combination of VA-ECMO with percutaneous microaxial pumps or implementation of a venoarteriovenous-ECMO configuration based on an additional venous cannula supplying towards pulmonary circulation are most promising among LV unloading and venting strategies. The latter may even combine the advantages of venovenous and venoarterial ECMO therapy, providing potent respiratory and circulatory support at the same time. However, whether VA-ECMO can reduce mortality has to be evaluated in the urgently needed, ongoing prospective randomized studies EURO-SHOCK (NCT03813134), ANCHOR (NCT04184635), and ECLS-SHOCK (NCT03637205). These studies will provide the opportunity to investigate indication, mode, and effect of LV unloading in dedicated sub-analyses. In future, the Heart Teams should aim at conducting a dedicated randomized trial comparing VA-ECMO support with vs. without LV unloading strategies in patients with cardiogenic shock.

Prognostic Implication of RV Coupling to Pulmonary Circulation for Successful Weaning From Extracorporeal Membrane Oxygenation

OBJECTIVES

The aim of this study was to explore if right ventricular (RV) contractile function and its coupling to pulmonary circulation (PC) were associated with successful weaning from venoarterial-extracorporeal membrane oxygenation (VA-ECMO) at maintenance of pump flow.

BACKGROUND

Limited data are available on predictors of successful weaning from VA-ECMO.

METHODS

A total of 79 patients with cardiogenic shock underwent transthoracic echocardiography to evaluate weaning from ECMO and were prospectively enrolled between 2016 and 2019. The noninvasively measured RV-PC coupling index was acquired by indexing tricuspid annular S' velocity, tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and RV free-wall longitudinal strain (FWLS) to right ventricular systolic pressure (RVSP).

RESULTS

Transthoracic echocardiography was performed at a median 3.0 days (range 1 to 6 days) after ECMO initiation at a median ECMO flow of 3.2 l/min (range 3.0 to 3.6 l/min). The RV-PC coupling matrix, tricuspid annular S'/RVSP, TAPSE/RVSP, and RV FWLS/RVSP exhibited satisfactory predictive performances for predicting successful weaning from ECMO. Using the best cutoff values derived from the area under the receiver-operator characteristic curve, tricuspid annular S'/RVSP demonstrated a significantly better predictive performance than conventional echocardiographic parameters (left ventricular ejection fraction >20%, left ventricular outflow tract time-velocity integral ≥10 cm, and mitral annular S' ≥6 cm/s).

CONCLUSIONS

Echocardiographic RV-PC coupling metrics exhibited a significantly better performance for predicting successful weaning from VA ECMO compared with conventional echocardiographic criteria at maintenance of pump flow.

The "TIDE"-Algorithm for the Weaning of Patients With Cardiogenic Shock and Temporarily Mechanical Left Ventricular Support With Impella Devices. A Cardiovascular Physiology-Based Approach

Objectives: Mechanical circulatory support (MCS) is often required to stabilize therapy-refractory cardiogenic shock patients. Left ventricular (LV) unloading by mechanical ventricular support (MVS) via percutaneous devices, such as with Impella® axial pumps, alone or in combination with extracorporeal life support (ECLS, ECMELLA approach), has emerged as a potential clinical breakthrough in the field. While the weaning from MCS is essentially based on the evaluation of circulatory stability of patients, weaning from MVS holds a higher complexity, being dependent on bi-ventricular function and its adaption to load. As a result of this, weaning from MVS is mostly performed in the absence of established algorithms. MVS via Impella is applied in several cardiogenic shock etiologies, such as acute myocardial infarction (support over days) or acute fulminant myocarditis (prolonged support over weeks, PROPELLA). The time point of weaning from Impella in these cohorts of patients remains unclear. We here propose a novel cardiovascular physiology-based weaning algorithm for MVS.

Methods: The proposed algorithm is based on the experience gathered at our center undergoing an Impella weaning between 2017 and 2020. Before undertaking a weaning process, patients must had been ECMO-free, afebrile, and euvolemic, with hemodynamic stability guaranteed in the absence of any inotropic support. The algorithm consists of 4 steps according to the acronym TIDE: (i) Transthoracic echocardiography under full Impella-unloading; (ii) Impella rate reduction in single 8–24 h-steps according to patients hemodynamics (blood pressure, heart rate, and ScVO₂), including a daily echocardiographic assessment at minimal flow (P2); (iii) Dobutamine stress-echocardiography; (iv) Right heart catheterization at rest and during Exercise-testing via handgrip. We here present clinical and hemodynamic data (including LV conductance data) from paradigmatic weaning protocols of awake patients admitted to our intensive care unit with cardiogenic shock. We discuss the clinical consequences of the TIDE algorithm, leading to either a bridge-to-recovery, or to a bridge-to-permanent LV assist device (LVAD) and/or transplantation. With this protocol we were able to wean 74.2% of the investigated patients successfully. 25.8% showed a permanent weaning failure and became LVAD candidates.

Conclusions: The proposed novel cardiovascular physiology-based weaning algorithm is based on the characterization of the extent and sustainment of LV unloading reached during hospitalization in patients with cardiogenic shock undergoing MVS with Impella in our center. Prospective studies are needed to validate the algorithm.

ECPella: Concept, Physiology and Clinical Applications

Addition of Impella on top of venoarterial extracorporeal membrane oxygenation (VA-ECMO) has gained wide interest as it might portend improved outcomes in patients with cardiogenic shock. This has been consistently reported in retrospective propensity-matched studies, case series, and meta-analyses. The pathophysiologic background is based on the mitigation of ECMO-related side effects and the additive benefit of myocardial unloading. In this perspective, thorough knowledge of these mechanisms is required to optimize the management of mechanical circulatory support with this approach and introduce best practices, as the interplay between the two devices and the implantation-explantation strategies are key for success.