Physical Activity, Subclinical Myocardial Injury, and Risk of Heart Failure Subtypes in Black Adults.

Objectives: This study sought to evaluate the independent associations and interactions between high-sensitivity cardiac troponin I (hs-cTnI) and physical activity (PA) with risk of heart failure (HF) subtypes, HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF).

Background: Black adults are at high risk for developing HF. Physical inactivity and subclinical myocardial injury, as assessed by hs-cTnI concentration, are independent risk factors for HF.

Methods: Black adults from the Jackson Heart Study without prevalent HF who had hs-cTnI concentration and self-reported PA assessed at baseline were included. Adjusted Cox models were used to evaluate the independent and joint associations and interaction between hs-cTnI concentrations and PA with risk of HFpEF and HFrEF.

Results: Among 3,959 participants, 25.1% had subclinical myocardial injury (hs-cTnI ≥4 and ≥6 ng/l in women and men, respectively), and 48.2% were inactive (moderate-to-vigorous PA = 0 min/week). Over 12.0 years of follow-up, 163 and 150 participants had an incident HFpEF and HFrEF event, respectively. In adjusted analysis, higher hs-cTnI concentration (per 1-U log increase) was associated with higher risk of HFpEF (hazard ratio [HR]: 1.47; 95% confidence interval [CI]: 1.25 to 1.72]) and HFrEF (HR: 1.57; 95% CI: 1.35 to 1.83]). In contrast, higher PA (per 1-U log increase) was associated with a lower risk of HFpEF (HR: 0.93; 95% CI: 0.88 to 0.99]) but not HFrEF. There was a significant interaction between hs-cTnI and PA for risk of HFpEF (p interaction = 0.04) such that inactive participants with subclinical myocardial injury were at higher risk of HFpEF but active participants were not.

Conclusions: Among Black adults with subclinical myocardial injury, higher levels of PA were associated with attenuated risk of HFpEF.