HEARTBEAT-TROP. Polyethylene Glycol Precipitation to Unmask Macrotroponin

Troponin elevation can be caused by acute coronary syndrome, myocarditis or structural heart disease. In most cases, troponin levels drop back to normal after the acute phase of the disease. In some cases, troponin elevation may persist despite clinical recovery due to macrocomplex formation. In athletes, this may cause unnecessary exclusion from competitive sport. Polypethylene glycol precipitation (PEG) has emerged as a cost-effective and feasible laboratory method to reveal macrotroponin. However, cut-off values have not been established for macrotroponin. PEG will be assessed in patients presenting with acute coronary syndrome (ACS) and undergoing invasive coronary angiography and compared to healthy controls, marathon runners who have undergone cardiological pre-participation screening and have been cleared for competition. 24 hours of rest are required before troponin levels are assessed in these athletes. In the control group of marathon runners, PEG will also be analyzed within one hour after crossing the finishing line. In both groups, blood lipids (LDL-cholesterol, lipoprotein a), blood glucose and hemoglobin 1Ac will be assessed at baseline. Transthoracic echocardiography will be performed in both groups at baseline. Also, in the marathon group echocardiography will be performed within one hour after completion of the race. PEG and echocardiography will also be repeated in the group of ACS within 24 hours before hospital discharge. The primary outcome is PEG recovery in both groups at presentation (upon emergency presentation in ACS and baseline examination in athletes). Secondary outcomes are PEG recovery values in the second exam (before discharge in ACS and within one hour after marathon completion in athletes), left and right ventricular ejection fraction in both groups during both exams. Athletes are defined as marathon participants older than 18 years without overt cardiovascular disease.

Inclusion criteria

• Age above 18 years
• Group with acute coronary syndrome (ACS): Diagnosis of ACS (ST-segment elevation or non-ST-segment elevation myocardial infarction according to the European Society of Cardiology Guidelines 2023 with at least one measurement of high sensitive troponin I or T above the 99th percentile of reference).
• Marathon runners: Participation in a marathon following cardiological pre-participation screening and medical clearance for competition. No clinical signs of cardiovascular or structural heart disease

Exclusion criteria

• Patients with acute coronary syndrome: Known macrotroponin, terminal renal disease (glomerular filtration rate below 10ml per minute), diagnosis of cancer, pregnancy
• Marathon runners: Coronary artery disease, structural heart disease, diagnosis of cancer, pregnancy