Abstract

Background: Studies in middle aged and older (masters) athletes with atherosclerotic risk factors for coronary artery disease (CAD) report higher coronary artery calcium (CAC) scores compared with sedentary individuals. Few studies have assessed the prevalence of CAD in masters athletes with a low atherosclerotic risk profile. Methods: We assessed 152 masters athletes aged 54.4±8.5 years (70% male) and 92 controls of similar age, sex and low Framingham 10 year CAD risk scores with an echocardiogram, exercise stress test, CT coronary angiogram, and cardiovascular magnetic resonance imaging (CMRI) with late gadolinium enhancement (LGE) and a 24-hour Holter. Athletes had participated in endurance exercise for an average of 31±12.6 years. The majority (77%) were runners with a median of 13 marathon runs per athlete. Results: Most athletes (60%) and controls (63%) had a normal CAC score. Male athletes had a higher prevalence of atherosclerotic plaques of any luminal irregularity (44.3% vs 22.2%;p=0.009) compared with sedentary males and only male athletes showed a CAC ≥300 Agatson units (AU) (11.3%), and a luminal stenosis ≥50% (7.5%). Male athletes demonstrated predominantly calcific plaques (72.7%) whereas sedentary males showed predominantly mixed morphology plaques (61.5%). The number of years of training was the only independent variable associated with increased risk of CAC >70th percentile for age and/or luminal stenosis ≥50% in male athletes: OR 1.08 (95% CI 1.01-1.15);p=0.016. 15 (14%) male athletes but none of the controls revealed LGE on CMRI. Of these, 7 had a pattern consistent with previous myocardial infarction including 3(42%) with a luminal stenosis ≥ 50% in the corresponding artery. Conclusions: Most lifelong masters endurance athletes with a low atherosclerotic risk profile have normal CAC scores. Male athletes are more likely to have a CAC score >300 AU or coronary plaques compared with sedentary males with a similar risk profile. The significance of these observations is uncertain but the predominantly calcific morphology of the plaques in athletes indicates potentially different pathophysiological mechanisms for plaque formation in athletic versus sedentary men. Whereas coronary plaques are more abundant in athletes, their stable nature could mitigate the risk of plaque rupture and acute myocardial infarction.