Troponin antibodies and macrotroponin: a common cause of troponin I elevation in elite endurance athletes

Abstract Background and Aims Elevations in cardiac troponin I (cTnI), a marker of myocardial injury, have been frequently observed in athletes after intense exercise. cTnI autoantibodies (cTnI Ab) and macrotroponin complexes can confound assessment, and we hypothesised that they may explain the paradox of repeated cTnI elevations in athletes. Methods Athletes and non-athlete controls underwent high-sensitivity cTnI testing, cardiac magnetic resonance imaging (CMR), 24-hour ambulatory electrocardiographic monitoring and VO 2 peak assessment. Athletes with cTnI values >99 th percentile sex-specific upper reference limit were assessed for cTnI Ab using polyethylene glycol (PEG) precipitation and troponin T (TnT)/TnI discordance. Results Overall, 456 participants were evaluated (387 athletes and 69 non-athletes). cTnI elevations were observed in 39 (10.1%) athletes and no (0%) control participants (p=0.002). Athletes with cTnI elevation demonstrated higher VO 2 peak and larger biventricular dimensions compared to athletes without cTnI elevations (p