Race duration and blood pressure are major predictors of exercise-induced cardiac troponin elevation.

BACKGROUND: The underlying mechanisms of the exercise-induced increase in cardiac troponins (cTn) are poorly understood. The aim of this study was to identify independent determinants of exercise-induced cTn increase in a large cohort of healthy recreational athletes.

METHODS: A total of 1002 recreational cyclists without known cardiovascular disease or medication, participating in a 91-km mountain bike race were included. Median age was 47 years and 78% were males. Blood samples were obtained 24 h prior to, and 3 and 24 h after the race.

RESULTS: Cardiac TnI concentrations increased markedly from baseline [1.9 (1.6-3.0) ng/L] to 3 h after the race [52.1 (32.4-91.8) ng/L], declining at 24 h after the race [9.9 (6.0-20.0) ng/L]. Similarly, cTnT increased from baseline [3.0 (3.0-4.2) ng/L] to 3 h after the race [35.6 (24.4-54.4) ng/L], followed by a decline at 24 h after the race [10.0 (6.9-15.6) ng/L]. The 99th percentile was exceeded at 3 h after the race in 84% (n = 842) of subjects using the cTnI assay and in 92% (n = 925) of study subjects using the cTnT assay. Shorter race duration and higher systolic blood pressure (SBP) at baseline were highly significant (p < 0.001) independent predictors of exercise-induced cTn increase both in bivariate and multivariable analysis. The age, gender, body mass index, training experience and cardiovascular risk of participants were found to be less consistent predictors.

CONCLUSION: Systolic blood pressure and race duration were consistent predictors of the exercise-induced cTn increase. These variables likely reflect important mechanisms involved in the exercise-induced cTn elevation.

TRIAL REGISTRATION NUMBER: NCT02166216 https://clinicaltrials.gov/ct2/show/NCT02166216.