2020 ESC Guidelines on Sports Cardiology: Impact of CMR Criteria on Return-to-Play Clearance After Acute Myocarditis

Cardiovascular magnetic resonance (CMR) imaging is a key component of current diagnostic pathways in subjects with acute myocarditis. The 2020 ESC Guidelines on Sports Cardiology recommend athletes with acute myocarditis to abstain from sports during the recovery phase from inflammation and to undergo comprehensive evaluation—including CMR—before safely returning to play. This retrospective study analyzed 95 non-competitive athletes presenting with acute myocarditis and evaluated by initial and repeated CMRs. CMR exams assessed myocardial inflammation, edema, and scarring as defined based on the updated Lake Louise criteria. As per 2020 ESC Guidelines, eligibility was granted by excluding extensive myocardial damage. Initial CMR showed 84% positive STIR (edema) and 79% with LGE ≥ 3 segments. After 3–6 months, STIR positivity dropped to 12%, LGE extent remained globally stable, but with some reduction in 42%. Few experienced recurrent myocarditis or LVEF decline; 24% met return-to-play criteria by repeated CMR. Our study shows that few non-competitive athletes recovering from acute myocarditis meet ESC CMR criteria to resume competitive sports at prescribed follow-up evaluation. The long-term prognostic value of CMR markers like LGE and edema remains unclear, highlighting the need for further research to refine return-to-play guidelines and ensure athlete safety.