A new study suggests that cardiac magnetic resonance (CMR) can help determine when athletes who have recovered from COVID-19 can safely return to play in competitive sports.

Researchers at Ohio State University (OSU, Columbus, USA) conducted a CMR imaging study in 26 college athletes (mean age, 19.5 years, 57.7% male) who tested positive for COVID-19 between June and August 2020, and following quarantine. The CMR examination included cine, T1 and T2 mapping, extracellular volume fraction, and late gadolinium enhancement (LGE). In addition, an electrocardiogram (ECG), serum troponin I, and transthoracic echocardiogram were performed on day of CMR imaging.

Overall, 12 of the athletes (26.9%) reported mild symptoms during the short-term infection period (sore throat, shortness of breath, myalgias, fever), while others were asymptomatic. There were no diagnostic ST/T wave changes on ECG, and ventricular volumes and function were within the normal range in all of the athletes, as shown by transthoracic echocardiogram and CMR imaging. No athlete showed elevated serum levels of troponin I.

The results showed four athletes (15%; all male) had CMR findings consistent with myocarditis, based on the presence of two main features of the updated Lake Louise Criteria: myocardial edema by elevated T2 signal and myocardial injury by presence of nonischemic LGE. Pericardial effusion was present in two of the athletes with CMR evidence of myocarditis. Mean T2 in those with suspected myocarditis was 59 milliseconds, compared to 51 milliseconds in those without CMR evidence of myocarditis. The study was published on September 11, 2020, in JAMA Cardiology.

“CMR has the potential to identify a high-risk group for adverse outcomes and may, importantly, risk stratify athletes for safe participation, as CMR mapping techniques have a high negative predictive value to rule out myocarditis,” said lead author cardiologist Saurabh Rajpal, MD. “Additionally, the CMR imaging ruled out myocarditis for all athletes without MRI evidence of inflammation, allowing them to return to playing sports.”

Myocarditis is an inflammation of the cardiac muscle which enlarges and weakens the heart, creates scar tissue, and forces it to work harder to circulate blood and oxygen throughout the body. Viral infections are a leading cause of myocarditis, with inflammation occurring during the course of infection, putting stress on the heart that remains even after the infection is resolved.

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