Abstract

Introduction: Patients with COVID-19 are at an increased risk of cardiovascular complications. Studies indicating an association between ABO blood groups and risk of cardiovascular outcomes were limited by small sample size or use of administrative claims data with uncertain validity. Aim: To study the association of non-O blood group and cardiovascular outcomes among patients with COVID-19 in a large cohort with adjudicated cardiovascular events. Methods: We examined patients from the CORONA-VTE Network registry with confirmed COVID-19 and ABO blood group data. The main outcome was major cardiovascular events including venous or arterial thrombosis, heart failure, myocarditis, new atrial fibrillation/flutter, and cardiovascular death. Outcomes were assessed at 90-day follow-up and adjudicated by independent physicians. Adjusted analyses were conducted accounting for age, sex, cancer, history of cardiovascular disease, history of hemodialysis, history of prior venous thromboembolism, and clustering of patients within sites. Results: Among 3,224 patients of whom 1,658 were inpatients (mean age: 66 ± 17.8) and 1,566 were outpatients (mean age: 52 ± 17.8), 767 (23.8%) inpatients and 728 (22.6%) outpatients had blood group O. Among inpatients, 90-day cumulative incidence of cardiovascular events was 16.9% (95% CI: 14.1-19.5%) for blood group O and 20.8% (95% CI: 18.1- 23.4%) for non-O blood group. Compared with patients with blood group O, those with non-O blood group had a higher risk of cardiovascular events in unadjusted (HR: 1.28, 95% CI: 1.02-1.60%, p=0.03), and adjusted analyses (HR: 1.26, 95% CI: 1.02-1.57%, p=0.04). In outpatients, 90-day event rates were 2.9% (95% CI: 1.7- 4.1%) for blood group O and 4.2% (95% CI: 2.8- 5.6%) for non-O blood group. The risk of cardiovascular events in outpatients with non-O blood group did not reach statistical significance, in unadjusted (HR: 1.46, 95% CI: 0.9-2.5, p=0.172) or adjusted analyses (HR: 1.36, 95% CI: 0.9-2.1, p=0.162). Conclusion: Inpatients with COVID-19 with non-O blood group have a higher risk of cardiovascular events in unadjusted and adjusted analyses. Future studies should explore if patients with non-O blood group may benefit from preventive strategies to mitigate this risk.