1University Hospital Klinikum rechts der Isar, Technical University of Munich Department of Preventive Sports Medicine and Sports Cardiology Munich, Deutschland; 2Balgrist University Hospital, University of Zurich University Center for Prevention and Sports Medicine Zurich, Schweiz; 3Klinikum rechts der Isar, Technical University of Munich Institute of AI and Informatics in Medicine Munich, Deutschland; 4Appalachian State University, and North Carolina Research Campus Human Performance Laboratory Kannapolis, NC, USA
BACKGROUND: Cardiac troponin (cTn) indicates myocardial injury. However, some degree of cTn increase is experienced by most athletes following strenuous exercise. Recent data suggest that exercise-induced cTn increases above the 99th percentile are associated with an increased risk for cardiovascular events. The prognostic value and the clinical applicability of these increases in marathon runners remain unclear.
PURPOSE: We investigated the linkage between marathon race-induced changes in hs-cTnT above and below the reference value in middle-aged male marathon runners and subsequent adverse cardiovascular events during a 10 year post-race period.
METHODS: In this prospective observational study, middle-aged male marathon runners of the Beer, Marathon, Genetics, Inflammation, and the Cardiovascular System (Be-MagIC) study were re-evaluated after 10 years. Hs-cTnT were measured prior, immediately, 24h, and 72h post-marathon and categorized above and below the reference value (RV) (>14 ng·L−1 or <14 ng·L−1). Furthermore, clinical endpoints were assessed over a 10-year period after the marathon race via self-reported questionnaires and clinical investigation. Major adverse cardiovascular events (MACE) were defined as follows: coronary artery diseases, myocardial infarction, atrial fibrillation, stroke, heart failure, moderate or severe valve regurgitation, and aortic dilatation.
RESULTS: A total of 130 male marathon runners (age 43±8 years; marathon time 03:48±0:29 h:min) were included. At baseline, none of the runners presented with clincally manifest cardiovascular diseases (CVD), and nearly all runners had "low to moderate" ESC 10-year CVD score (2.0%±1.0%). Baseline hs-cTnT above the RV were detectable in 2 (1.5%) runners. Hs-cTnT level increased immediatly post-marathon (from 3.0 ng·L−1 [3.0-5.1] pre-race to 29.7 ng·L−1 [18.5-45.5] post-race, p<0.001). In total, 111 runners (85.4%) had hs-TnT levels above the RV immediately post-marathon. After 24h and 72h, hs-TnT levels above the RV were detectable in 33 (25.4%) and 6 (4.6%) runners, respectively. In total, 55 (42.3%) had MACE after 10 years. Of the runners with hs-cTnT increase above the RV immediately post-race, 47 of 111 (42.3%) had MACE after 10 years of follow-up, compared with n=8 of 19 (42.1%) of runners with post-marathon hs-TnT increases under the RV (p=1.000; Table 1). Of runners with prolonged hs-cTnT (pecTnT) elevation above the RV 24h or 72h post-race, 17 of 33 (51.5%) had MACE, compared with 37 of 96 (38.5%) runners with post-marathon hs-TnT under the RV (p=0.223).
CONCLUSION: Cardiovascular events were similar after 10 years in middle-aged asymptomatic male runners with immediately post-marathon race hs-cTnT increases above the RV compared to runners with hs-cTnT below the RV. The percentage of cardiovascular events was higher in runners with a pecTnT above the RV compared to runners with a hs-cTnT below the RV.