Abstract Body (Do not enter title and authors here): Background: The prevalence of heart failure (HF) is expected to increase with the aging of the U.S. population. A national evaluation of the epidemiology of HF among Medicare beneficiaries was last published in 2017, with a documented overall increase in HF mortality in the US thereafter. Evaluating contemporary population-based rates and survival for HF is essential to advancing public health and targeted improvements in healthcare delivery.

Research Question: What are contemporary national rates and mortality for HF among Medicare beneficiaries, including across demographic subgroups?

Methods: A population-based cohort study was conducted among 100% Medicare fee-for-service (FFS) beneficiaries 66 years or older from 2017 to 2023. Prevalent HF was identified using ICD-10 codes in the inpatient, outpatient, or clinician claims. Incident HF was defined by 1 inpatient or 2 outpatient claims among those without a diagnosis of HF in the prior year. Incidence and prevalence rates were calculated per 1,000 beneficiaries. Trends in incidence, prevalence, and mortality were assessed by age, sex, race, and ethnicity.

Results: Among 166,513,463 Medicare beneficiaries with FFS part A and B enrollment, 13.2% (n=22,044,098) had prevalent HF and 3.8% (n=6,310,126) had an incident HF diagnosis. Subjects with incident HF had a mean (SD) age of 79.6 (8.1) years, of whom 52.3% were female (n=3,302,842), 7.5% were Black (n=473,803), 83.9% were White (n=5,292,160), and 4.4% were Hispanic (n=280,376). Variability in the prevalence overall, incidence overall and by age, sex, race, and ethnicity, and one-year overall mortality among incident patients is displayed in Figure 1. Over the study period, the rates of incident HF decreased from 39.9 to 38.1 (p-value < .0001), while the prevalence of HF increased from 132.7 to 135.4 (p-value = .0005). The incidence of HF decreased in all populations from 2017 to 2023. Overall, one-year mortality following incidence HF decreased from 26.7% to 24.2% (p-value < .0001).

Conclusions: The epidemiology of HF among Medicare beneficiaries is evolving with decreased incidence and increased prevalence. The decreases in incidence have occurred overall and across patient demographic subgroups. While one-year mortality among incident HF has decreased, it remains almost 25%. These trends highlight improvements in the prevention of HF and the continued critical need to implement current HF therapies and develop novel therapeutics to reduce mortality.