Impact of a mountain ultra-marathon (UTMB) on cardiac biomarkers

OBJECTIVES: While moderate exercise has beneficial effects on the cardiovascular system, consequences of a supraphysiological effort are not clear yet. In particular, the physiological consequences of ultramarathons need to be further documented. The aim of the study was to assess the changes of various cardiac biomarkers after a mountain ultramarathon.
MATERIAL AND METHODS: Blood and urine samples were collected on 28 runners (17 men) participating to the UltraTrail du Mont Blanc (105 km, total positive elevation: 5600 m) at 3 different times: before the race (Pre), within 1 h after the finish (Post) and 7 days after the finish (D+7). Several biomarkers involved in heart disease (coronary syndrome, heart failure and fibrosis) and in inflammation were assayed on different analyzers such a COBAS® (for CKMB,TnThs, NTproBNP, HFABP and CRPs) and KRYPTOR® (for Copeptin). ST2 was measured manually with the Presage kit from CRITICAL DIAGNOSTIC®.
RESULTS: Plasma levels of cardiac markers (CKMB, TnThs, NTproBNP, copeptin, HFABP, ST2) and inflammation (CRPs) increased significantly at Post. Means values increased from Pre to Post as follows: 2.3 to 91.9 UI/L for CKMB (p<0.0001); 7.6 to 31.7 ng/L for TnThs (p<0.0001); 41.7 to 1190.5 ng/L for NTproBNP, 4.2 to 22.9 pmol/L for copeptin (p=0.001); 3.6 to 107.8 ng/mL for HFABP (p<0.0001), 29.7 to 126.2 ng/mL for ST2 (p<0.0001); 0.5 to 29.1 mg/L for CRPs (p<0.0001). With the exception of a few (HFABP, ST2, CRPs) biomarkers in some subjects, all values were back to Pre values at D+7.
DISCUSSION/CONCLUSION: Prolonged strenuous running exercise caused an elevation in cardiac biomarkers. Elevation in CKMB levels lacks specificity for cardiac damage as runners have increased CKMB from skeletal muscles as well. Previous studies suggested that exercise induced TnThs elevation is a benign reversible physiologic phenomenon but this parameter, as well as HFABP, could be a sign of ischemia. Different phenomena occurred such as stretch of myocytes causing an increase in pressure or volume and neurohormonal activation which can explain the Copeptine and NTproBNP increase, while ST2 is a biomarker of cardiac remodeling and fibrosis. CRP is an acute phase compound that tends to increase following a strenuous and prolonged bout of exercise and/or muscular injury. As the values tended to return within the normal reference range values within 7 days after the race, our study suggests that there is no permanent structural damage at the myocardium level.