Exercise Cardiac Power And Coronary Artery Calcification In Men

Abstract

PURPOSE: Low exercise cardiac power (ECP), defined as a ratio of peak oxygen consumption with peak systolic blood pressure during exercise, is associated with adverse cardiovascular events, but the underlying mechanisms remain unclear. Coronary artery calcification (CAC) as a surrogate marker of atherosclerosis is associated with an increased risk of cardiovascular outcomes. We tested the hypothesis that lower levels of ECP may be associated with the prevalence of CAC, independent of conventional risk factors, in a cross-sectional study of 2165 (age 53±6 yrs, range 40-78 yrs) men. METHODS: We measured CAC using multidetector computed tomography using the Agatston coronary artery calcium score. The prevalence of CAC was defined as dichotomous variables of CAC score >0. ECP was calculated by a ratio of peak oxygen consumption with peak systolic blood pressure and classified into quartiles. RESULTS: The presence of CAC was inversely associated with ECP quartiles (both, P < .001 for trend). After adjusting for age, BMI, SBP, HDL-C, hsCRP, glucose, heart rate, smoking, hypertension and diabetes, men in the lowest quartile of ECP had a significantly elevated odds ratios for having CAC (odds ratio (OR) 1.43, 95% CI 1.06-1.93), compared with men in the highest quartile of ECP. Each ECP unit increment as a continuous variable was associated with 4% (OR 0.96, 95% CI 0.93-0.99) lower prevalence of CAC after adjusting for established risk factors. CONCLUSIONS: Our findings demonstrate that lower levels of ECP are associated with the prevalence of coronary artery calcification, which could contribute to increased risk of cardiovascular events.