Life's Essential 8 and Incident Cardiovascular Disease in U.S. Women With Breast Cancer.

Background: Relationships between lifestyle risk factors and cardiovascular disease (CVD) risk in women with breast cancer (BC) are underexplored.

Objectives: To evaluate the incidence of CVD in relation to the Life's Essential 8 (LE8) score among women with BC.

Methods: Data from the Women's Health Initiative were utilized. The primary exposure was the LE8 score assessed prior to BC diagnosis. The LE8 score was stratified into low (0-59), moderate (60-79), and high (80-100) cardiovascular health (CVH). The primary endpoint was a composite of incident CVD events, which included coronary heart disease, defined as myocardial infarction along with coronary revascularization, CVD death, and stroke. We calculated the cumulative incidence of CVD and estimated hazard ratios.

Results: Among 7,165 participants, the median age was 70.1 years at BC diagnosis. The mean LE8 score was 62.0 ± 12.2. Over a median follow-up period of 6 years, 490 composite CVD events occurred. The risk of CVD events was highest for low CVH compared with moderate and high CVH. Compared with low CVH, the hazard ratio for incident CVD was 0.57 (95% CI: 0.46-0.69) for moderate CVH and 0.34 (95% CI: 0.20-0.59) for high CVH. LE8, in conjunction with age, provided a C-statistic of 0.74 for the composite risk of CVD.

Conclusions: Higher LE8 scores were associated with a lower risk of incident CVD among women with BC in the United States.