Comorbidities Associated With Myocarditis In Hospitalized COVID-19 Patients

INTRODUCTION: While COVID-19 is predominantly a lung infection, it can cause systemic viremia in susceptible patients and lead to cardiac involvement and myocarditis (MC); an inflammation of the myocardium characterized by arrhythmias, cardiogenic shock, acute heart failure, and death. Although rare, there is evidence of a surge in MC-related admissions during the COVID-19 pandemic, implying a correlation. However, the risk factors associated with MC susceptibility in these patients remain unclear. This study aims to assess the comorbidities and demographic features associated with the development of MC in adult patients with COVID-19. METHODS: Data were obtained from the PearlDiver database (PearlDiver Technologies, Fort Wayne, IN). The database provides all-payers administrative claims data on the patient level. Using ICD-10-CM codes, a cohort of patients hospitalized with a primary diagnosis of COVID-19 was identified. The study included only patients admitted to the hospital between January and October 2020 to minimize bias associated with vaccine-related MC. Within this cohort, patients diagnosed with MC during and up to one month after admission were identified and their demographic features and comorbidities to were compared to those without MC. We calculated Risk Ratios with their respective 95% CI. A p-value <0.05 was deemed significant. RESULTS: We found 627,465 admissions due to COVID-19 from January to October 2020, with 506 (0.08 %) diagnosis of MC. Patients with MC were more likely to be males (60%), younger (mean age 48, SD= 23 vs. 60, SD =17 - p<0.01), and they had more comorbidities (mean Elixhauser Comorbidity Index: 7.52, SD= 5 vs. 6.9, SD = 5 - p<0.001). The development of MC was significantly associated with a history of coagulopathies [0.55(0.46-0.66); p<0.0001], asthma [1.20 (1.06-1.23); p= 0.01], deep venous thrombosis [1.54(1.38-1.68); p<0.0001], renal disease[1.15 (1.02-1.27); p= 0.03], congestive heart failure [1.24 (1.12-1.34); p=0.006], ischemic heart disease [1.25 (1.14-1.35); p=0.0001], and arrhythmias [1.24 (1.14-1.32); p< 0.0001]. However, a history of diabetes [0.89 (0.67-0.99); p=0.02], hypertension [0.71 (0.62-0.80); <0.000.1], depression [0.71(0.52-0.88); p=0.0001], and hypothyroidism [0.42(0.08-0.69); p<0.0001] was associated with lower risk of MC-related hospitalization. Other preexistent conditions including, psychosis, rheumatoid arthritis, cerebrovascular disease, obesity, tobacco use, alcohol abuse, HIV, anemia, peripheral vascular disease, and non-metastatic solid tumor were not significantly correlated with MC. DISCUSSION: MC is a rare yet serious complication of COVID-19. Therefore, a better knowledge of the pathophysiology of COVID-19 and the patient factors associated with development to MC is crucial for prognostication and providing risk-adjusted treatment. CONCLUSION: Patients with a history of cardiovascular disease, renal and pulmonary disease were more likely to develop MC as a result of COVID-19. However, hypertension and diabetes were associated with lower risk of MC, which warrants further investigation.