In patients with acute heart failure who are treated with extracorporeal life support (ECLS), in-hospital mortality is high; independent predictors of ECLS mortality include age, simplified acute physiology score (SAPS) II, new liver failure, and the number of allogenic blood transfusion units administered per day. These are among findings of a 13-year, single-center study recently published in Journal of Thoracic Disease.

The researchers sought to describe in-hospital mortality among patients who required ECLS, to identify independent predictors linked to mortality, and to analyze changes in mortality rates over time. Toward that end, a retrospective, observational, single-center study was conducted at the University Hospital Zurich in Switzerland — a tertiary care referral hospital and a designated ECLS center — between January 2007 and December 2019. Only cases with veno-arterial cardiocirculatory or cardiopulmonary support were considered for the study.

Indications for ECLS therapy were grouped according to 4 categories: (1) postcardiotomy, (2) cardiopulmonary resuscitation, (3) refractory cardiogenic shock, and (4) other. The “postcardiotomy group” included those with ECLS indications of intraoperative weaning failure from cardiopulmonary bypass and postoperative refractory cardiogenic shock. Those in the “cardiopulmonary resuscitation group” comprised patients who were treated with ECLS during cardiac arrest or immediately following return of spontaneous circulation. The category “other” included those with ECLS indications for expansive thoracic surgery, including lung transplantation.


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During the 13-year study period, ECLS therapy was needed in a total of 679 hospital patients. The mean patient age was 60 years; 27.5% of the patients were female. In-hospital mortality was reported in 55.5% (377 of 679) of the patients. That rate varied significantly between the indications for ECLS: 70.7% (152 of 215) of patients postcardiotomy; 67.9% (108 of 159) of those receiving cardiopulmonary resuscitation; 47.0% (110 of 234) of those with refractory cardiogenic shock; and 9.9% (7 of 71) among those undergoing lung transplantation or other expansive thoracic surgery (P <.001).

Cubic spline interpolation did not reveal any evidence of a change in mortality over the 13-year study period. Logistic regression modeling demonstrated excellent discrimination in the receiver operating characteristic (ROC) area under the curve (AUC) of 0.89 (95% CI, 0.87-0.92). This finding surprised investigators, who said they had “expected a mortality reduction over the years, due to the gained knowledge and improvement in the ECLS treatment.”

Investigators recognized that their study was limited by the fact that technologic and process improvements had occurred during the 13-year study period, thus creating considerable bias.

According to the investigators, “Knowledge of predictors strongly associated with in-hospital mortality may affect future decisions about ECLS indications and the respective management to use this elaborate therapy more effectively.”

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Sahli SD, Kaserer A, Braun J, et al. Predictors associated with mortality of extracorporeal life support therapy for acute heart failure: single-center experience with 679 patients. J Thorac Dis. 2022;14(6):1960-1971. doi:10.21037/jtd-21-1770