Abstract 3542: Coronary Atherosclerosis Burden and the Number of Marathons Predict the Presence of Myocardial Late Enhancement in Asymptomatic Healthy Master Marathon Runners
Background: In the presence of coronary atherosclerosis, bursts of exercise, such as marathon running, may trigger acute cardiac events. Data on underlying mechanisms are sparse. In this study, we examined the effect of the number of marathons, the Framingham risk score (FRS), and coronary artery calcium (CAC) burden on the presence of myocardial late-enhancement (LE) in apparently healthy master marathon runners.
Methods: In 108 runners aged 50–72 yrs with at least 5 marathon races during the past 3 yrs, the effect of the running history, the FRS, and the EBT-based Agatston-CAC-burden on the prevalence of MRI-based LE were evaluated using asymptotic logistic regression analysis. Due to few LE events, an exact logistic regression model comprising two independent variables with p-values assessed from Monte Carlo simulation was also calculated. As results from the models differed only marginally, we only report asymptotic logistic regression results.
Results: In the entire cohort, the FRS was 7.0±3.6% / 10 yrs. Runners had completed 20 marathons (median value). A CAC score >100 and >400 was observed in 36% and 13% of runners, respectively. Of 102 runners with successful MRI-studies, 12 (12%) had LE, n=5 with a subendocardial LE-pattern suggestive of ischemic origin and n=7 with midmyocardial LE suggestive of non-ischemic origin. In univariate analysis, CAC burden (odds ratios (OR) per 100 units: 1.16; 95%CI: 1.02–1.32, p=0.03), CAC percentile values (OR per 5 units: 1.17; 1.03–1.34, p=0.02), and the (log-transformed) number of marathons (OR per doubling the number of runs: 1.62; 1.07–2.46, p=0.02), but not the FRS (p=0.2) were associated with the presence of LE. In multivariate analysis, which had to be limited to 2 independents, CAC percentile values (OR: 1.19; 1.03–1.38, p=0.02) and the number of marathons (OR: 1.65; 1.08–2.52, p=0.02) remained independently associated with the presence of LE.
Conclusion: Coronary atherosclerosis and frequent marathon running contribute to subclinical myocardial damage, which may trigger sudden cardiac events. Considering the high prevalence of CAC and LE in these presumably healthy master athletes, an increased awareness of subclinical disease seems warranted to reduce event rates associated with marathon running.