Learners will review methods such as transthoracic echocardiography, cardiac MRI, and biomarkers (e.g., troponin-T and microRNA) for identifying heart-related complications in COVID-19 patients.
Learners will interpret the results and implications of the cohort study, focusing on the lack of myocardial injury in both groups despite persistent symptoms.
Introduction: Coronavirus disease 2019 (COVID-19) has been a major source of morbidity and mortality worldwide. Long-COVID and individuals with continued cardiorespiratory symptoms after COVID-19 infection remains a poorly understood disease process. It has been hypothesized that COVID-19 infection even in the absence of critical illness and significant comorbidities may cause myocardial injury, potentially explaining these ongoing symptoms, but this has not been definitively shown in the literature. Purpose: This prospective cohort study aims to determine the prevalence of COVID-19 myocardial injury amongst healthy U.S. active-service members with persistent cardiorespiratory symptoms following COVID-19 infection. Methods: 36 healthy active-duty service members with no cardiac or pulmonary medical comorbidities and persistent cardiopulmonary symptoms following COVID-19 infection confirmed by Polymerase Chain Reaction nasal swab were recruited. Subjects were evaluated for potential myocardial injury with laboratory testing (troponin-T, microRNA), electrocardiogram, and advanced cardiovascular imaging with transthoracic echocardiography and cardiac magnetic resonance imaging. 16 asymptomatic healthy control subjects with no cardiac or pulmonary disease underwent the same testing and served as the control arm. Patients in the comparison group either had no history of COVID-19 infection, or a prior history of COVID-19 infection without cardiovascular symptoms during or after the infection. Results: The study cohort had a median age of 32 years, 63% were men, 67% were white race, and 63% were fully vaccinated against COVID-19 prior to their initial infection. All subjects had no history of critical illness from COVID-19 infection, history of cardiopulmonary disease, or significant cardiac or pulmonary comorbidities. None of the subjects in the cohort exhibited elevated serum troponin-T or microRNA levels indicative of myocardial injury. Additionally, there was no evidence of infrahissian conduction disease, prior infarction, or myocardial injury on a 12-lead ECG. There were no statistically significant differences in the median left or right ventricular systolic function or chamber dimensions, median left ventricular strain, myocardial work indices, or median T1 or T2 parametric times as assessed by echocardiography and magnetic resonance imaging between the subjects in the two study arms. Conclusion: This prospective study found no evidence of myocardial injury amongst healthy subjects with persistent cardiopulmonary symptoms after COVID-19 infection and no history of critical illness or cardiopulmonary disease. No differences were observed in imaging parameters or microRNA data between the study cohort and the asymptomatic control arm.