Abstract Body: Objective: Over 3 million Americans have heart failure with preserved ejection fraction (HFpEF). Effective guideline directed medical treatments (GDMT) are increasingly available but patients with HFpEF are likely under-detected (particularly women) and not receiving GDMT. Limited data are available informing the extent of HFpEF under-detection in the community.

Hypothesis: Among patients with undifferentiated dyspnea and a high risk for unrecognized HFpEF, fewer than 50% will receive a HFpEF diagnosis during two years of follow-up; underrecognition will be greater among women.

Methods: We identified 22,134 patients aged ≥30 in the Rochester Epidemiology Project (a medical records linkage system comprising a 27-county region of southeastern Minnesota and western Wisconsin) with evidence of unexplained dyspnea (≥2 ICD codes for dyspnea separated by >1 day) without prior documented etiology including HF or lung disease, during the time period 2018-2022. We calculated the recently validated HFpEF-Age-BMI-Atrial Fibrillation (HFpEF-ABA) score to estimate the probability of underlying HFpEF. Cox proportional hazards models regressed risk for incident HFpEF diagnosis on HFpEF-ABA score (dichotomized as ≥80% vs. <80%) with multivariable adjustment for sex, race and ethnicity. HRs(95%CIs) are presented.

Results: Patients were 59±16 yrs, 50.8% women, 88.6% white, 3.1% Black, 3.7% other race, 4.6% Hispanic. Atrial fibrillation prevalence was 9.4% and mean BMI=31.4±7.8. Prevalence of HFpEF-ABA≥80% was 22.4%(n=4,958): 22.7% among women and 22.1% among men. The cumulative incidence of clinically-recognized HFpEF diagnosis at two years follow-up was 9.7% among women and 12.8% among men (log-rank p<0.01). HFpEF incidence was elevated with high HFpEF-ABA scores(≥80%): HR(95%CI) among women=3.72 (3.35, 4.14), and men=3.42 (3.11, 3.76). Among those with clinically diagnosed HFpEF during follow-up, mean time from date of first dyspnea ICD code to HFpEF diagnosis was 1.26 years overall: 1.31 and 1.21 years in women and men, respectively (p=0.05).

Conclusions: One in five patients with undifferentiated dyspnea have probable undiagnosed HFpEF, and of that group, only 30% receive a clinical diagnosis, requiring an average of over 1 year to be recognized. The rate of diagnosis is even lower among women than men. Further study is warranted to implement evidence-based algorithms supporting detection of undiagnosed HFpEF in the community, especially in women.