Sex-Related Prognosis of VA-ECMO–Treated Cardiogenic Shock: A Post Hoc Analysis of the HYPO-ECMO Trial

BACKGROUND: The sex-related prognosis of patients with cardiogenic shock undergoing venoarterial extracorporeal membrane oxygenation remains unclear. Our analyses aim to assess sex-specific outcomes in patients with cardiogenic shock receiving venoarterial extracorporeal membrane oxygenation and explore whether the effect of moderate hypothermia on clinical outcomes was modified by sex. METHODS: In this post hoc analysis of the HYPO-ECMO trial (Hypothermia During ECMO), clinical outcomes were compared by sex. The primary outcome was 30-day all-cause mortality. Key secondary outcomes included all-cause mortality and a composite outcome of all-cause mortality, heart transplant, escalation to left ventricular assist device implantation, or stroke at 30, 60, and 180 days. RESULTS: Among the 334 patients enrolled in the trial, 81 (24%) were female. At 30 days, 45.7% of female and 46.6% of male patients experienced the primary outcome, with no sex differences (adjusted odds ratio, 1.01 [0.57-1.78]; P=0.98 and log-rank test; P=0.93). No significant sex differences were observed in all-cause mortality at 60 and 180 days (adjusted odds ratio, 0.87 [0.49-1.52]; P=0.61 and 0.83 [0.47-1.46]; P=0.51, respectively) or in the composite outcome up to 180 days (P>0.2 for all). The effect of moderate hypothermia on the primary outcome (adjusted odds ratio, 0.73 [0.43-1.25]; P=0.25 and 0.67 [0.26-1.76]; P=0.41, in male and female, respectively, interaction P=0.88) and secondary outcomes (interaction P>0.3 for all) was not modified by sex. CONCLUSIONS: In this post hoc analysis of the HYPO-ECMO trial, male and female patients experienced similar outcomes in cardiogenic shock treated with venoarterial extracorporeal membrane oxygenation. Sex did not significantly modify the effect of moderate hypothermia on outcomes. REGISTRATION: URL: https://clinicaltrials.gov/study/NCT02754193; Unique identifier: NCT02754193.