Cardiac Troponin Fragmentation After Heavy Physical Exercise The MaraCat2 Study

Cardiac troponins are highly sensitive and specific biomarkers of cardiac injury and are in a key role in the diagnosis of acute myocardial infarction (MI). Minor troponin elevations are common after prolonged strenuous exercise without clinical symptoms of MI or myocardial injury.

Based on a small gel filtration chromatography study the released troponin in this condition seems to be predominantly in the form of small fragments. These smaller cytosolic troponin fragments may more easily traverse across cell membranes that have become leaky but not irreversibly damaged. Importantly, currently used high-sensitivity troponin T (cTnT) test detects also smaller troponin fragments which may lead to false diagnosis of MI.

In a Proof-of-Principle study we developed a novel immunoassay which is much simpler and more sensitive than previously used laboratory methods for studying cTnT fragmentation. In the present study protocol, we compare the characteristics troponin release after marathon race and Type 1 MI with the improved version of our novel troponin fragmentation test (SuperTropo test) and the commercial cTnT test.

A total of 65 recreational runners participating in the 2023 Paavo Nurmi Marathon in Turku are recruited to the MaraCat2 Study with an open email invitation. All participants give a blood sample during the post-race visit (within 60 min after finishing the marathon).

A control group of 90 patients with acute Type 1 MI are recruited among patients admitted to Heart Centre of Turku University Hospital. Coronary angiography is performed in all included patients to confirm culprit lesion and the MI diagnosis. All included patients are treated with primary or urgent percutaneous coronary intervention. Only patients with <24 delay from symptom onset to blood sample are included to avoid the effects of later gradual fragmentation of cTnT in the circulation.