Publications

Striving for Consensus in Myocarditis Diagnosis

One of the lessons learned from the COVID-19 pandemic, was that it was difficult to properly characterize SARS-CoV-2 related heart injury. Many groups defaulted to diagnosing any cardiovascular dysfunction as myocarditis. In evaluations of autopsy reports, it was noted that histologic descriptions of myocarditis were wildly variable between centers. Therefore, we set out to determine how expert pathologists would make the diagnosis of myocarditis on the same set of slides. This project is part of a larger multi-year/multi-institution project to better define the histopathologic traits of myocarditis. Eight international cardiovascular pathology experts evaluated 100 endomyocardial biopsy cases that had no myocarditis, borderline myocarditis, or myocarditis, as defined by the Dallas Criteria. We found that for obvious cases of myocarditis or non-myocarditis, it was relatively easy to reach consensus. However, for intermediate levels of inflammation and/or myocyte injury, the experts struggled to consistently obtain consensus. These results will inform us on how to move forward with improved myocarditis criteria that can be more consistently rendered between individuals and institutions.