Comparison of conventional and highly-sensitive troponin I measurement in ultra-marathon runners

Cardiac troponins are a mainstay in the diagnostic approach of patients with suspected acute coronary syndrome. Along with other causes of cardiac injury, strenuous aerobic exercise is an important source of troponin leakage from myocardium. Due to recent immunoassays development, there is no information on variation of highly-sensitive (HS) troponin I (TnI) in ultra-marathon runners. We studied 15 healthy trained Caucasian athletes before and immediately after completion of a 60 km, ultra-marathon. TnI was measured with both the conventional AccuTnI and the novel HS-AccuTnI immunoassays. At the end of the ultra-marathon the concentration of HS-AccuTnI significantly increased from the baseline value (19.2 ± 4.2 vs. 5.2 ± 0.8 ng/l; P = 0.001). The number of athletes displaying HS-AccuTnI values exceeding the 99th percentile of the reference limit was 2 (13%) pre-exercise, increasing significantly to 12 (80%; P < 0.001) post-exercise. Measurable value of AccuTnI were found in 1 (7%) and 12 (80%; P < 0.001) athletes pre- and post exercise, respectively. All AccuTnI values were below the 99th percentile reference limit pre-exercise, whereas this cut-off was overcome in 20% of athletes, post-exercise. These results suggest that the myocardium release of TnI during strenuous aerobic exercise mirrors that of troponin T. Moreover, the improved sensitivity of the HS-AccuTnI over the conventional assay makes it more suited for detecting even minor elevations of TnI in blood.