LAUSR

Background Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used to manage refractory cardiac failure. This study attempts to characterize the clinical outcomes and weaning success rates of patients placed on VA-ECMO. Methods An IRB-approved retrospective chart review of VA-ECMO cases at UCLA from 2015-2019 was conducted. Inclusion criteria included initiation of VA-ECMO for cardiac arrest, primary graft dysfunction, and cardiogenic shock. Diagnoses with primarily right ventricular failure were excluded. The primary outcome was survival at 30 days after ECMO decannulation without relapse to mechanical circulatory support. Patients were stratified into “weaned” verses “not weaned” groups. Weaned patients were further stratified into “successfully weaned” verses “unsuccessfully weaned” based on 30 day survival. Hemodynamic, laboratory, and echocardiogram parameters were compared. Echocardiograms prior to ECMO decannulation were reviewed for LV/RV systolic function and valvular function. T test was used to determine statistical significance among clinical parameters. Results Preliminary analysis showed that 117 patients met inclusion criteria. 43% were weaned from ECMO while 57% were unable to be weaned. Characteristics of both groups are described (Figure). The most common indications for ECMO were cardiac arrest and cardiogenic shock, the average duration was >100 hours, and bleeding was the leading complication. Among weaned patients, 84% survived to 30 days post-decannulation (Figure). 41 (82%) patients were successfully weaned compared to 9 (18%) who were unsuccessful (8 died, 1 relapsed to ECMO). Between the two groups, hemodynamic and laboratory parameters were similar (Figure). The average left ventricular ejection fraction on lowest ECMO flow rates was 43% in the successfully weaned group compared to 42% in the unsuccessfully weaned group. On average, both groups had mild right ventricular dysfunction. Conclusions While less than 50% of patients placed on VA-ECMO were weaned and decannulated, the majority of weaned patients survived to 30 days post-decannulation without relapse to mechanical circulatory support. These data suggest that clinical data, as described here, can be used when determining whether to wean patients off ECMO. Further studies are needed to evaluate clinical metrics that can be used to refine the ECMO weaning process and improve post-decannulation outcomes.