Background The female preponderance in heart failure with preserved ejection fraction (HFpEF) is a distinguishing feature of this disorder, but the association of sex with degree of diastolic dysfunction and clinical outcomes among individuals with HFpEF remains unclear. Methods and Results We conducted a prospective, multicenter, observational study of patients with HFpEF (PURSUIT-HFpEF [Prospective Multicenter Observational Study of Patients with Heart Failure with Preserved Ejection Fraction]: UMIN000021831). Between 2016 and 2019, 871 patients were enrolled from 26 hospitals (follow-up: 399±349 days). We investigated sex-related differences in diastolic dysfunction and postdischarge clinical outcomes in patients with HFpEF. The echocardiographic end point was diastolic dysfunction according to American Society of Echocardiography/European Association of Cardiovascular Imaging criteria. The clinical end point was a composite of all-cause death and heart failure readmission. Women accounted for 55.2% (481 patients) of the overall cohort. Compared with men, women were older and had lower prevalence rates of hypertension, coronary artery disease, and chronic kidney disease. Women had diastolic dysfunction more frequently than men (52.8% versus 32.0%, P<0.001). The incidence of the clinical end point did not differ between women and men (women 36.1/100 person-years versus men 30.5/100 person-years, P=0.336). Female sex was independently associated with the echocardiographic end point (adjusted odds ratio, 2.839; 95% CI, 1.884-4.278; P<0.001) and the clinical end point (adjusted hazard ratio, 1.538; 95% CI, 1.143-2.070; P=0.004). Conclusions Female sex was independently associated with the presence of diastolic dysfunction and worse clinical outcomes in a cohort of elderly patients with HFpEF. Our results suggest that a sex-specific approach is key to investigating the pathophysiology of HFpEF. Registration URL: https://upload.umin.ac.jp; Unique identifier: UMIN000021831.
Keywords: diastolic dysfunction; heart failure; preserved left ventricular function; prognosis; sex.