Debate or consensus on the path that leads to successful extracorporeal membrane oxygenation decannulation?

Central MessageWhile significant progress has been made in using ECMO in patients with cardiogenic shock, the weaning criteria for successful decannulation remain incompletely defined.See Article page XXX. While significant progress has been made in using ECMO in patients with cardiogenic shock, the weaning criteria for successful decannulation remain incompletely defined. See Article page XXX. Although venoarterial (VA) extracorporeal membrane oxygenation (ECMO) has been used more and more frequently to bridge patients with cardiogenic shock (CS) to recovery, criteria for weaning these patients that lead to successful decannulation are poorly defined and vary widely from institution to institution. Moreover, in-hospital mortality remains high for patients supported for CS. In this issue, Zhang and colleagues1Zhang A. Kurlansky P. Ning Y. Wang A. Kaku Y. Fried J. et al.Outcomes following successful decannulation from extracorporeal life support for cardiogenic shock.J Thorac Cardiovasc Surg. XXX, 2022; ([Epub ahead of print])Abstract Full Text Full Text PDF Scopus (1) Google Scholar present a large series of 510 patients with CS supported with VA ECMO and attempt to clarify criteria that predict successful weaning, which was defined as survival ≥30 days or to discharge. The authors present an impressive 1-year survival rate of 95% among patients successfully weaned from ECMO; however, decannulation was only successful in 48.8% of their cohort. Patients with primary graft dysfunction were more likely to be successfully weaned, and those with extracorporeal life support during cardiopulmonary resuscitation were at greater risk of mortality. In addition, acute myocardial infarction (MI) and renal or hepatic dysfunction were associated with in-hospital mortality after decannulation. Decannulation decisions were based on bedside weaning trials and considered hemodynamic parameters in the context of gradually decreasing flow rates. Importantly, echocardiographic parameters before decannulation were not assessed in this study. There are some noteworthy differences between the series of Zhang and colleagues1Zhang A. Kurlansky P. Ning Y. Wang A. Kaku Y. Fried J. et al.Outcomes following successful decannulation from extracorporeal life support for cardiogenic shock.J Thorac Cardiovasc Surg. XXX, 2022; ([Epub ahead of print])Abstract Full Text Full Text PDF Scopus (1) Google Scholar and our published institutional experience with successful ECMO weaning in patients supported for CS.2Sertic F. Chavez L. Diagne D. Richards T. Wald J. Acker M. et al.Predictors of in-hospital mortality and midterm outcomes of patients successfully weaned from venoarterial extracorporeal membrane oxygenation.J Thorac Cardiovasc Surg. 2021; 161: 666-678.e3Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar In our cohort, patients with acute-on-chronic heart failure, especially patients with an ejection fraction <30%, had lower rates of successful weaning, reflecting the severity of their preexisting heart condition. This differs from the data presented in this issue, potentially because patients bridged to a ventricular-assist device or transplant were included in the survivor cohort in the study of Zhang and colleagues.1Zhang A. Kurlansky P. Ning Y. Wang A. Kaku Y. Fried J. et al.Outcomes following successful decannulation from extracorporeal life support for cardiogenic shock.J Thorac Cardiovasc Surg. XXX, 2022; ([Epub ahead of print])Abstract Full Text Full Text PDF Scopus (1) Google Scholar We would caution against interpreting these findings too optimistically, as a closer review of the data reveals that if patients who received a ventricular-assist device/transplant had been excluded, the majority of the patients with CS due to heart failure would not have survived. In patients with CS, we have found that echocardiographic parameters are particularly important in weaning decisions, as they allow us to carefully consider right and left ventricular function and the presence of valvular abnormalities. Significant valvular abnormalities, especially those that result in severe regurgitation, and pulmonary involvement manifested by hypoxemia before decannulation are markers for poor prognosis. Our experience suggests that examining hemodynamics alone is not sufficient. Time on VA ECMO support is also associated with increased mortality, especially if support is extended for more than 10 to 14 days. In the past, this has forced a rapid de-escalation of support to prevent thromboembolic complications.3Distelmaier K. Wiedemann D. Binder C. Haberl T. Zimpfer D. Heinz G. et al.Duration of extracorporeal membrane oxygenation support and survival in cardiovascular surgery patients.J Thorac Cardiovasc Surg. 2018; 155: 2471-2476Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar More recently, other technologies, including high-power catheter-based axial flow pumps (eg, Impella 5.5; Abiomed), have allowed us to prolong support with less morbidity. With this strategy, we have had increasing success bridging patients with acute MI to recovery after revascularization. This differs from the finding of Zhang and colleagues1Zhang A. Kurlansky P. Ning Y. Wang A. Kaku Y. Fried J. et al.Outcomes following successful decannulation from extracorporeal life support for cardiogenic shock.J Thorac Cardiovasc Surg. XXX, 2022; ([Epub ahead of print])Abstract Full Text Full Text PDF Scopus (1) Google Scholar that patients with acute MI had a greater risk of mortality, which we believe was probably related to shorter support times. This difference emphasizes the importance of considering platform modifications when ECMO weaning is not feasible after several days to provide prolonged support and increase the chances of successful recovery. Overall, our collective combined experience suggests that while we have made significant progress in using ECMO in patients with CS, there is still much work to be done, and criteria for successful decannulation remain incompletely defined. We congratulate the authors for their elegant description of their institutional experience, excellent outcomes, and for an additional perspective on a protocol for successful decannulation in complex and clinically challenging patients. Outcomes following successful decannulation from extracorporeal life support for cardiogenic shockThe Journal of Thoracic and Cardiovascular SurgeryPreviewAlthough 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. Full-Text PDF