Prevalence and predictors of cardiac troponin elevations following exercise: a systematic review, meta-analysis, and meta-regression

AIMS: Myocardial injury is defined by cardiac troponin (cTn) elevations exceeding the upper reference limit (URL) and serves as a diagnostic criterion for myocardial infarction. However, exercise can also elevate cTn, complicating interpretation. We aimed to determine the prevalence and predictors of cTn elevations following exercise. METHODS: We conducted a random-effects meta-analysis of post-exercise cTn elevations above the assay-specific URL. Associations between prespecified covariates and the prevalence of elevated post-exercise cTn were assessed using multilevel mixed-effects meta-regression and cubic spline models. RESULTS: We identified 4,312 articles and included 129. The cohort consisted of 7,289 athletes (78% male; mean age 44.9 years; median exercise duration 4.2 hours). Overall, 36% (95%CI 31-42%) of athletes demonstrated cTn concentrations above the URL following exercise, with extreme between-study heterogeneity (range 2-98%). The prevalence was higher with high-sensitivity versus non-high-sensitivity assays (58% versus 26%), cTnT versus cTnI assays (45% versus 30%), and in middle-aged individuals. Sex and training status were not associated with elevations. Endurance sports, including triathlon (49%), cycling (40%), and running (41%), showed the highest prevalence, while contact sports (6%) and walking (8%) showed the lowest. The prevalence was non-linearly associated with exercise duration, with a peak (52%) after 3-6 hours of exercise. CONCLUSIONS: cTn elevations are common following exercise, most often with high-sensitivity assays and cTnT measurements, particularly in endurance sports lasting 3-6 hours. Clinicians should consider assay type and exercise characteristics rather than sex and training status when evaluating post-exercise cTn elevations in athletes.