Long-Term Cardiovascular and Mortality Risk in Patients with Pre-Existing Arrhythmia Post-SARS-CoV-2 Infection

<b>Background/Objectives:</b> Individuals with arrhythmia who survived COVID-19 could be susceptible to long-term cardiovascular complications and clinical outcomes. <b>Methods:</b> We performed a retrospective cohort study of adults with a history of arrhythmia in the Montefiore Health System (1 January 2016-17 August 2024). COVID-19 status was determined by a positive or negative polymerase-chain-reaction test. Outcomes included all-cause mortality, first-time myocardial infarction (MI), heart failure (HF), ischemic or hemorrhagic stroke, and major adverse cardiovascular events (MACE: defined as MI, HF, stroke, or death) > 30 days post-index date. Cox proportional hazards and Fine-Gray competing risk models, adjusted for demographic, clinical, socioeconomic, and COVID-19 vaccination variables, were employed. The association of outcomes with blood biomarkers taken at time of infection were also assessed in hospitalized COVID-19 patients. <b>Results:</b> Among the 6830 arrhythmia patients, 985 were hospitalized for COVID-19, 1591 were not hospitalized for COVID-19, and 4254 did not have COVID-19. Patients hospitalized for COVID-19 had a higher risk of all-cause mortality (adjusted hazard ratio = 2.90, 95% confidence-interval [2.08, 4.04]), first-time MI, HF, and MACE compared to controls without COVID-19. No increased risk was observed among non-hospitalized COVID-19-positive patients compared to controls, except for all-cause mortality. Older age, male sex, Medicaid, and significant comorbidities were associated with the risk of MACE. Elevated levels of creatinine, lactate dehydrogenase, D-dimer, neutrophil-to-lymphocyte ratio, low hemoglobin, and low left ventricular ejection fraction during infection were associated with higher future MACE risk. <b>Conclusions.</b> In individuals with arrhythmia, severe COVID-19 is associated with increased long-term risks of mortality and new-onset cardiovascular complications, while mild infection with mortality risk. These findings highlight the need for long-term cardiovascular monitoring in this population.