Long-term risk of cardiovascular events after COVID-19 in the Swedish adult population-A matched cohort study.

BACKGROUND: The long-term risk across severity strata of people infected with SARS-CoV-2 has not yet been comprehensively described. METHODS: Using nationwide registries, all COVID-19 cases in Sweden with <2 vaccine doses, with and without initial hospitalization (February 1, 2020 to June 30, 2022), were identified and matched with non-COVID comparators. Participants were followed during the early, intermediate, long-term, and extended phases (365+ days) regarding death, acute myocardial infarction (AMI), ischemic stroke (IS), or heart failure (HF), and a composite of major adverse cardiovascular events (MACEs). Hazard ratios (HRs) were estimated using Cox proportional hazard regression adjusted for age, sex, obesity, hypertension, need of assisted living, Nordic origin, education, and Charlson Comorbidity Index. RESULTS: We identified 1,024,623 nonhospitalized (mean age: 40.4 years, 48.1% men) and 49,855 hospitalized (mean age: 58.8 years, 58.9% men) COVID-19 cases who were matched with 1,022,266 and 249,142 non-COVID comparators, respectively. Overall, nonhospitalized cases had no remaining risk of MACE past the early phase following COVID-19 infection. Among hospitalized cases, the risk of MACE remained elevated into the long-term and extended follow-up period (HRs 1.70 [confidence interval (CI) = 1.56-1.86] and 1.62 [CI = 1.51-1.72]) compared with comparators. After 365 days, they had a persistently increased risk of death (HR = 1.75, CI = 1.62-1.89), IS (HR = 1.40, CI = 1.18-1.67), HF (HR = 2.07, CI = 1.74-2.45), and AMI (HR = 1.28, CI = 1.07-1.53), compared with non-COVID comparators. CONCLUSIONS: Hospitalized COVID-19 cases continued to have a nearly doubled risk of cardiovascular events and death after the first year of follow-up, whereas nonhospitalized cases had risks comparable to population comparators.