Big Ten Programs Suggest Good Sensitivity of Post-COVID Cardiac MRI

Cardiac MRI boosted the detection of myocarditis among college athletes with recent SARS-CoV-2 infection, according to data from the Big Ten Conference.

Myocarditis, whether clinical or subclinical, was observed in 2.3% of 1,597 athletes undergoing cardiac MRI as part of comprehensive medical testing after testing positive for COVID-19. Rates of myocarditis ranged from 0% to 7.6% across 13 participating universities, reported Curt Daniels, MD, of Ohio State University in Columbus, and colleagues.

Testing protocols were closely tied to the detection of myocarditis: if cardiac testing was based on cardiac symptoms alone, the detected prevalence of myocarditis would have been just 0.31%; with a strategy using ECG, echocardiogram, and troponin findings, the detected prevalence would have been 0.81%.

Further exploration of the role of cardiac MRI in routine screening for athletes’ safe return to play (RTP) should be considered, the study authors noted in JAMA Cardiology.

Myocarditis is an established risk factor for sudden cardiac death among athletes. Myocardial injury is well described in various populations with SARS-CoV-2 infection.

“CMR [cardiac MRI] imaging is highly sensitive for identifying myocardial inflammation and in our study was able to exclude significant disease and allow safe RTP in 97.7% of athletes after cardiac screening. While there may be a concern that CMR imaging is too sensitive and therefore unduly restrict athletes from sport, such a scenario would only account for a very small proportion of the population based on our study,” wrote Daniels and co-authors.

Yet a trio led by James Udelson, MD, of Tufts Medical Center in Boston, disagreed in an accompanying editorial.

Routine cardiac MRI would be impractical — too much of a burden on any healthcare system or athletic program, they argued, adding that the currently falling COVID-19 cases can be expected to translate to a lower pretest probability of finding myocarditis over time.

“Hence, the rapid evolution of data in this area continues to support the idea that the more practical and more widely available approach of testing with ECG, echocardiography, and serum troponin likely improves specificity and decreases burden of potentially unwarranted athletic restriction,” Udelson’s group wrote.

This conservative first-line approach had been recommended by the American College of Cardiology Sports and Exercise Council in October 2020.

“It can be discussed with stakeholders that a more intensive CMR imaging strategy will identify another 1 to 2 cases in every 100 individuals screened, resulting in restriction of activity, but whether that affects clinical course is uncertain,” the editorialists noted.

Study authors agreed that the short- and long-term clinical implications of COVID-19 myocarditis are unknown.

“To address these concerns, we must find ways to minimize the variability in performance among academic centers to diagnose myocarditis, perhaps through standardized evidence-based diagnostic algorithms and testing protocols, and when indicated, standardization of CMR protocols and interpretation,” they urged.

The study was based on the Big Ten COVID-19 Cardiac Registry with data spanning March 1 to December 15, 2020. Program leaders detailed COVID-19 findings and the extent of their cardiac testing in a survey.

In total, there were 9,255 athletes tested for SARS-CoV-2 infection, of whom 2,810 tested positive and 1,597 subsequently received complete cardiac MRI evaluation. Notably, cardiac MRI was only required for RTP starting in September 2020.

Of the 37 student athletes diagnosed with COVID-19 myocarditis, nine had clinical myocarditis and 28 had subclinical myocarditis.

A median 22.5 days had passed from a positive COVID-19 test to cardiac testing and diagnosis of myocarditis. Although program clinicians agreed to use Lake Louise criteria for myocarditis, diagnosis was up to individual program clinicians.

Follow-up MRIs in 27 athletes showed resolution of T2 elevation in 100% and late gadolinium enhancement in 40.7%.

Daniels and colleagues cautioned that their observational study was subject to possible selection bias, given that not all infected athletes underwent cardiac MRI. Furthermore, program leaders provided no individual-level information for the study.

“We can be reasonably certain that the prevalence of signs on CMR imaging of myocarditis using the modified Lake Louise criteria is in the range of 1% to 3% in athletes following positive COVID-19 test results,” Udelson’s group maintained.

“We certainly at this point know a lot more than we did just 6 months ago. We can applaud the sports cardiology community for the remarkable progress in such a short period, bringing all of these data to light and enabling a far more informed and data-driven approach to our efforts to ensure a safe return to play for young athletes,” the editorialists concluded.