Parity and Heart Failure Risk in Diabetic Women with Coronary Artery Disease: A Multicenter Cohort Study.

BACKGROUND: Women with type 2 diabetes (T2DM) and coronary artery disease (CAD) face elevated heart failure (HF) risk compared with men. Although population-based studies have linked parity to cardiovascular outcomes, evidence is limited among women with established cardiovascular disease. We investigated the association between parity and HF hospitalization and mortality in women with T2DM and CAD. METHODS: This multicenter retrospective cohort study enrolled 2,314 women with T2DM and CAD from 70 hospitals between 2005 and 2022 in Japan. Participants were stratified by parity and followed for a median of 2,297 days. Outcomes included HF hospitalization, all-cause mortality, acute myocardial infarction (AMI), and stroke. Cox proportional hazards models adjusted for age, cardiovascular risk factors, and medication use. RESULTS: Women with ≥5 births had significantly higher incidences of HF hospitalization (4.90 vs 3.03 per 100 person-years) and mortality (4.85 vs 3.76 per 100 person-years) compared with <5 births. After adjustment, high parity (≥5 births) was significantly associated with HF hospitalization (HR: 1.41, 95% CI: 1.04-1.90) but not with mortality (HR: 1.22, 95% CI: 0.92-1.62). No associations were observed with AMI or stroke. CONCLUSIONS: Among women with T2DM and CAD, high parity independently and outcome specifically predicted HF hospitalization, regardless of accumulated cardiovascular risk factors. Reproductive history should be considered in HF risk stratification even for high-risk women.