Increase of high sensitivity cardiac troponin I and NT-proBNP in competitive athletes after a 50-km ultramarathon race: physiological adaptation or myocardial injury?

Abstract

BACKGROUND: High-sensitivity cardiac troponins I (hs-cTnI) and T (hs-cTnT) and natriuretic peptides (BNP and NT-proBNP) are universally recognized as reference cardiac biomarkers in patients with acute coronary syndromes and heart failure, respectively. Recent studies have shown that these biomarkers can be increased even in healthy competitive athletes after intense and prolonged physical exercise. However, it is not yet clear whether the increase in these cardiac-specific biomarkers should be considered a normal physiological adaptation to physical exercise or a real myocardial injury. The aim of this study was to evaluate hs-cTnI and NT-proBNP levels in healthy competitive athletes before and after a 50-km ultramarathon.METHODS: We enrolled 16 competitive male athletes with an average age of 32 years who participated in a 50-km ultramarathon race. Before the race, all athletes underwent cardiovascular tests in accordance with national regulations for competitive sports. The study protocol involved collecting blood samples 1 hour before the start of the race (T0) and 30 minutes after the end of the race.RESULTS: No athlete had any adverse cardiac events or angina or other symptoms during or after the race. At T0 hs-cTnI and NT-proBNP values were within the reference ranges in all athletes. Data analysis showed that hs-cTnI significantly increased from 4.93±1.12 ng/L (T0) to 28.75±11.45 ng/L after the race (T1) (P<0.001). Among these athletes, 5 (31.25%) had hs-cTnI values above the 99th percentile URL of 34 ng/L. On the other hand, NT-proBNP also significantly increased from 26.81±8.77 ng/L (T0) to 98.5±38.87 ng/L after the race (T1) (P>0.001). Among these athletes, 4 (25%) had NT-proBNP values above the 99th percentile URL of 125 ng/L.CONCLUSIONS: Our data demonstrated a significant increase in both cardio-specific biomarkers, sometimes with values beyond URL, after a 50-km ultramarathon race in competitive athletes with previous normal cardiac examinations.