Sex Differences in Heart Failure With Reduced Ejection Fraction in the GALACTIC-HF Trial

Background: Women with heart failure with reduced ejection fraction (HFrEF) receive less guideline-recommended therapy and experience worse quality of life than men. Objectives: The authors sought to assess differences in baseline characteristics, outcomes, efficacy, and safety of omecamtiv mecarbil between men and women enrolled in the GALACTIC-HF (Registrational Study With Omecamtiv Mecarbil [AMG 423] to Treat Chronic Heart Failure With Reduced Ejection Fraction) study. Methods: In GALACTIC-HF, patients with symptomatic heart failure with EF of 35% or less, recent heart failure event, and elevated natriuretic peptides were randomized to omecamtiv mecarbil or placebo. The current analysis investigated differences in baseline characteristics, clinical outcomes, and efficacy and safety of omecamtiv mecarbil between men and women. Results: Of 8,232 patients analyzed, 21.2% were women. Women more likely self-identified as being Black, had worse symptoms (lower Kansas City Cardiomyopathy Questionnaire Total Symptom Score [KCCQ-TSS]), and were less likely to be treated with angiotensin receptor/neprilysin inhibitor and devices at baseline. Compared with men, women had lower rates of the primary endpoint (adjusted HR: 0.80, 95% CI: 0.73-0.88). Sex did not significantly modify omecamtiv mecarbil's treatment effect (P interaction = 0.68). Women also had 20% less risk of cardiovascular death, heart failure event, and all-cause death. Women participants had lower rates of serious adverse events. Conclusions: Women participants of the GALACTIC-HF trial had worse quality of life and were less likely to be treated with guideline-based therapies at baseline. Despite KCCQ-TSS being predictive of poor outcomes in this population, women had a 20% lower risk of an HF event or cardiovascular death compared with men. The beneficial effect of omecamtiv mecarbil did not significantly differ by sex. (Registrational Study With Omecamtiv Mecarbil [AMG 423] to Treat Chronic Heart Failure With Reduced Ejection Fraction [GALACTIC-HF]; NCT02929329).