Abstract Body: Background: Based on data largely from ambulatory epidemiological cohorts, the prevalence of heart failure with preserved ejection fraction (HFpEF) has increased substantially in the past decade, particularly among women. However, contemporary trends and sex differences in the distribution of HF subtypes among US patients newly hospitalized with HF remains unknown. Here, we aimed to evaluate contemporary trends and sex differences in the distribution of HF subtypes among US patients newly hospitalized with HF in a national registry.

Methods: Using the Get With The Guidelines®-Heart Failure registry, we assessed temporal trends in the proportions of heart failure subtypes (HFpEF; EF ≥ 50%; HF with mildly reduced/reduced EF [HFmr/rEF]; EF < 50%) in patients hospitalized with incident HF between 2005 and 2022. Linear regression was used to assess annual changes in the prevalence of HFpEF among hospitalizations with incident HF.

Results: Of 372,623 patients with incident HF hospitalizations across 1,081 facilities, 184,977 (49.6%) had HFpEF, 180,731 (48.5%) were women, and 245,561 (65.9%) were age 65 years or older. Over the 18-year period, women with incident HF had a higher proportion with HFpEF (60.5%) versus men (39.3) (risk ratio = 1.54; 95% confidence interval [CI]: 1.53 – 1.55; p<0.001). Among women hospitalized with incident HF, the proportion with HFpEF increased from 51% in 2005 to 61% in 2022, an annual change of 0.39% (95% CI: 0.32% - 0.45%; p_trend <0.001) per year. Over the same period among men, the proportion with HFpEF rose from 28% to 41%, an annual change of 0.61% (0.55%, 0.67%; p_trend <0.001) per year.

Conclusions: By 2022, approximately 50% of patients hospitalized with incident HF had HFpEF. More women with incident HF had HFpEF than men, but men had greater annual increase in the proportion of HFpEF among incident HF hospitalizations. Greater efforts for targeted prevention of HFpEF, particularly for women, are needed.