Handling persistent cardiac troponin elevation in asymptomatic athletes: The role of macrocomplexes.

Study objective: Return-to-play (RTP) decision includes cardiac troponin I returning to baseline. Formation of antibodies to cardiac troponin I (macrocomplexes) may lead to persistent, false positively elevated cardiac troponin I and may induce unnecessary exclusion from competitive sports. Design: Single-centre retrospective study. Setting: Sports cardiological outpatient clinic. Participants: We investigated 12 asymptomatic athletes who had clinically recovered from their first episode of acute myocarditis, but who showed persistently elevated cardiac troponin I levels without kinetics. Interventions: Testing for the presence of macrocomplexes using an Abbott high-sensitivity cardiac troponin I assay with and without polyethylene glycol (PEG) precipitation to precipitate any potential macrocomplexes present in the samples. Main outcome measures: Prevalence of a cardiac troponin I recovery rate in PEG precipitation. Results: 13 samples from 12 athletes (mean age 36.2 ± 12.3 years) were examined with a cardiac troponin I range from 35.4 ng/L to 951 ng/L. After PEG precipitation, a measurable cardiac troponin I concentration was detected in only two cases. In 12 of the 13 samples examined, the cardiac troponin I recovery rate was below 35%, which suggests the presence of macrocomplexes. Mean time from diagnosis of acute myocarditis to assessment of macrocomplexes was 6.2 ± 3.6 months. Conclusion: Formation of macrocomplexes seems to be highly prevalent in athletes who have clinically recovered from acute myocarditis. PEG precipitation may be a feasible laboratory approach to help in the clinical decision-making of athletes to avoid unnecessary exclusion from competitive sports.