PURPOSE: To prospectively analyze the myocardial distribution of late gadolinium 
enhancement (LGE) with delayed-enhancement cardiac magnetic resonance (MR) 
imaging, to compare the prevalence of this distribution in nonprofessional male 
marathon runners with that in asymptomatic control subjects, and to examine the 
prognostic role of LGE.
MATERIALS AND METHODS: Institutional review board and ethics committee approval 
were obtained for this study, and all subjects provided written informed 
consent. Two-dimensional inversion-recovery segmented k-space gradient-echo MR 
sequences were performed after administration of a gadolinium-containing 
contrast agent in 102 ostensibly healthy male runners aged 50-72 years who had 
completed at least five marathons during the past 3 years and in 102 age-matched 
control subjects. Predominantly subendocardial regions of LGE typical of 
myocardial infarction (hereafter, coronary artery disease [CAD] pattern) were 
distinguished from a predominantly midmyocardial patchy pattern of LGE 
(hereafter, non-CAD pattern). Marathon runners with LGE underwent repeat cardiac 
MR imaging and additional adenosine perfusion imaging. Runners were followed up 
for a mean of 21 months +/- 3 (standard deviation) after initial presentation. 
The chi(2), Fisher exact, and McNemar exact tests were used for comparisons. 
Event-free survival rates were estimated with the Kaplan-Meier method, and 
overall group differences were evaluated with log-rank statistics.
RESULTS: Of the 102 runners, five had a CAD pattern of LGE, and seven had a 
non-CAD pattern of LGE. The CAD pattern of LGE was located in the territory of 
the left anterior descending coronary artery more frequently than was the 
non-CAD pattern (P = .0027, Fisher exact test). The prevalence of LGE in runners 
was higher than that in age-matched control subjects (12% vs 4%; P = .077, 
McNemar exact test). The event-free survival rate was lower in runners with 
myocardial LGE than in those without myocardial LGE (P < .0001, log-rank test).
CONCLUSION: Ostensibly healthy marathon runners have an unexpectedly high rate 
of myocardial LGE, and this may have diagnostic and prognostic relevance.