Abstract 11179: Changes in Cardiomyocyte Structure on Endomyocardial Biopsy Following COVID-19 Infection

Case Presentation: A 24-year-old unvaccinated male with a history of NYHA Class II heart failure and morbid obesity presented with 4 days of chest pain and shortness of breath, and was found to have COVID-19 pneumonia. History included non-ischemic cardiomyopathy (NICM) with an LVEF of 33%. Troponin was 40 ng/L (ref <=53 ng/L) and NT pro-BNP 1915 pg/mL (ref <125 pg/mL). TTE showed LVEF 18.5% with severe global hypokinesis. As a participant in a clinical trial investigating heart rate modulation in NICM, 106 days prior to his positive COVID-19 PCR he had an endomyocardial biopsy (EmBx) revealing unremarkable myocytes (Figure 1A & B). His end-of-study EmBx (118 days after COVID-19 infection) showed scattered hypertrophic cardiomyocytes with enlarged hyperchromatic nuclei and T-tubule dilation (Figure 1 C & D). Discussion: Recent studies have described several types of myocardial injury related to COVID-19 infection. This is the first report to compare myocardial histopathological findings pre- and post-infection. The post-infection EmBx demonstrating cardiomyocyte hypertrophy and T-tubule dilation along with worsening LVEF on TTE were associated with progressive myocardial dysfunction following a recent COVID-19 infection. T-tubule changes have been correlated with abnormal cardiomyocyte contractile mechanics in animal models, although not previously described in relation to COVID-induced myocardial dysfunction. Limitations include the duration between his infection and biopsy as well as receipt of a study drug (ivabradine or placebo), though unlikely to impact the histopathology results. Figure 1: Endomyocardial histology and electron microscopy (EM) findings A, Pre-COVID with minimal pathologic findings (100x, H&E); B, Pre-COVID EM with normal intercalated disc (arrow) and mitochondria (arrowhead); C, Post-COVID with scattered hypertrophic cardiomyocytes (100x, H&E); D, Post-COVID EM with t-tubule dilation (arrows)