Associations Between Cardiorespiratory Fitness (CRF) in Early Adulthood, Retention Through Midlife, and Heart Failure (HF) Stages: Findings From Coronary Artery Risk Development in Young Adults (CARDIA) Study

Introduction: Prior studies demonstrate that poor CRF in early adulthood is associated with adverse cardiac structure and function in midlife. The purpose of this study is to examine if higher early adulthood CRF and retention of CRF through midlife are associated with lower subsequent risk of subclinical or clinical HF. Methods: CARDIA participants with available data on CRF at baseline (Year [Y] 0: 1985-86), follow-up (Y7 or Y20), and HF staging data by Y30 were included. CRF was estimated using treadmill duration from a maximal, symptom-limited graded exercise test via modified Balke protocol. An adjusted linear mixed model was used to estimate treadmill duration when CRF assessment was missing at Y7 or 20. HF stages were defined using AHA HF staging criteria, including Stage 0 (no HF risk factors). Clinical HF was adjudicated by committee. Adjusted multinomial models tested associations between Y0 CRF and percent CRF retained through Y20 with HF stages at Y30, with Stage 0 as the reference. Interactions by the four race-sex groups were examined. Results: Of 2,565 individuals (25.1±3.5 y, 43% Black, 55% female), 30% (n=778), 37% (n=952), 32% (n=813), and 1% (n=32) were classified as Stages 0, A, B, or C/D by Y30 exam, respectively. Compared with Stage 0, every 1-minute increment higher CRF in early-adulthood was associated with a lower adjusted odds ratio of HF [Stage A: 0.72 (95% CI 0.68, 0.76), Stage B: 0.80 (95% CI 0.75, 0.84), Stage C/D 0.86 (95% CI 0.71, 1.04)]. Compared with Stage 0, every 1-standard deviation of % CRF retained at Y20 (midlife) was also associated with a lower odds of Stage A, B, and C/D HF at Y30 (Figure). A race-sex interaction was not observed (p-interaction 0.42). Conclusion: Higher early adulthood CRF, and greater retention of CRF through midlife, were associated with lower risk of developing subclinical or clinical HF. Strategies to maintain optimal CRF across the young adulthood to midlife transition may be important in prevention of HF.