Two biomarkers for the screening of cardiac risk among runners ?

Background Heart-type fatty acid-binding protein (H-FABP) is a low molecular weight protein involved in the intracellular uptake and buffering of long chain fatty in the myocardium. Troponin T is a component of the contractile apparatus of the striated musculature. Both are early markers for acute coronary syndrome.

Objective The aim of our study was to compare the results obtained with the H-FABP and the highly sensitive cardiac troponins (hsTnT) and to test their cardiospecificity in healthy runners.

Design Prospective, cohort study.

Setting Amateur marathon runners.

Patients 23 runners (marathon) were enrolled.

Interventions We drowned blood samples at three times: just before (T0), just after (T1), and three hours after the end of the race (T3).

Main outcome measurements H-FABP and hs-TnT were performed according to the manufacturer's instructions. A linear regression was calculated to observe if there is any correlation between the two biomarkers. Values above the 95th percentile for H-FABP (2.5 ng/mL) and the 99th percentile for hsTnT (14 ng/L) were considered as positive.

Results At T0, none of the subjects were positive for hsTnT but 35% were positive for H-FABP; at T1, 83% for hsTnT and 100% for H-FABP; at T3, 83% for hsTnT and 96% for H-FABP. At T0, the regression equation was H-FABP T0=3.9454–0.1001×hsTnT T0; at T1: H-FABP T1=51.838–1.7026×hsTnT T1; at T3: H-FABP T3=47.977–1.6193×hsTnT T3. No correlation was observed between the 2 biomarkers.

Conclusion We observed a significant increase of H-FABP and hsTnT in runners. These markers are independent to each other. These values could biologically correspond to a heart ischemia. These biomarkers could be helpful for the screening of cardiac risk among runners.