The effects of a 50 km ultramarathon race on high sensitivity cardiac troponin I and NT-proBNP in highly trained athletes.

BACKGROUND: High sensitivity cardiac troponins I (hs-cTnI) and T (hs-cTnT) and natriuretic peptides (BNP and NT-proBNP) are universally recognized as cardiac reference biomarkers in patients with acute coronary syndromes and heart failure respectively. However, while on one hand the high sensitivity methods of cardiac biomarkers have provided answers to fundamental pathophysiological and clinical questions in patients with heart disease, less information is available on their assessment in paraphysiological conditions, such as high intensity exercise in healthy athletes. The aim of this study was to evaluate hs-cTnI and NT-proBNP in highly trained runners after a 50 km ultramarathon. METHODS: We have enrolled 20 highly trained male athletes who have run a 50 km ultramarathon. Blood samples were collected 2 hours before the start of the race (T0) and 20 minutes after the end of the race (T1). The blood concentrations of hs-cTnI and NT-proBNP measured before the race were within reference intervals in all runners. RESULTS: Hs-cTnI significantly increased after the end of the race (median: 19 ng/L [IQR: 12.5-25.75] versus 6 ng/L [IQR: 4.25-8.0]; P<0.001), in three cases over the upper reference limit (URL) of 34 ng/L. NT-proBNP also significantly increased (median: 78 ng/L [IQR: 68.25-87.75] versus 22 ng/L [IQR: 18.25-26.75]; P<0.001). Three other athletes reached concentration over the URL (125 ng/L). CONCLUSIONS: Our study showed a significant increase in hs-cTnI and NT-proBNP in highly trained athletes after a 50 km ultramarathon race, and 30% of runners had the values of cardiac biomarkers above URL. More studies with a larger number of athletes will be needed to better understand the effects of intense exercise on the heart of trained athletes.

The European Biological Variation Study (EuBIVAS): weekly biological variation of cardiac troponin I estimated by the use of two different high-sensitivity cardiac troponin I assays.

Background Cardiac troponins (cTn) are specific markers for cardiac damage and acute coronary syndromes. The availability of new high-sensitivity assays allows cTn detection in healthy people, thus permitting the estimation of biological variation (BV) of cTn. The knowledge of BV is important to define analytical performance specifications (APS) and reference change values (RCVs). The aim of this study was to estimate the within- and between-subject weekly BV (CVI, CVG) of cTnI applying two high-sensitivity cTnI assays, using European Biological Variation Study (EuBIVAS) specimens. Methods Thirty-eight men and 53 women underwent weekly fasting blood drawings for 10 consecutive weeks. Duplicate measurements were performed with Singulex Clarity (Singulex, USA) and Siemens Atellica (Siemens Healthineers, Germany). Results cTnI was measurable in 99.4% and 74.3% of the samples with Singulex and Atellica assays, respectively. Concentrations were significantly higher in men than in women with both methods. The CVI estimates with 95% confidence interval (CI) were for Singulex 16.6% (15.6-17.7) and for Atellica 13.8% (12.7-15.0), with the observed difference likely being caused by the different number of measurable samples. No significant CVI differences were observed between men and women. The CVG estimates for women were 40.3% and 36.3%, and for men 65.3% and 36.5% for Singulex and Atellica, respectively. The resulting APS and RCVs were similar for the two methods. Conclusions This is the first study able to estimate cTnI BV for such a large cohort of well-characterized healthy individuals deriving objective APS and RCV values for detecting significant variations in cTnI serial measurements, even within the 99th percentile.