Arterial Cardiovascular Disease Risk After Venous Thromboembolism in Young Adults: A Danish Nationwide Cohort Study

Background Young adults account for a substantial proportion of patients with venous thromboembolism (VTE). It is not known whether this group is at elevated risk of arterial cardiovascular disease (CVD). Methods In a Danish nationwide cohort study from 1996 to 2021, we estimated incidence rates and cumulative incidence as a measure of CVD risk (myocardial infarction and ischemic stroke) in young adults (≤40 years of age) with a VTE. Cox proportional hazards regression models were used to compute hazard ratios (HRs) with corresponding 95% confidence intervals (95%CIs), adjusted for comorbidities, using an age- and sex-matched (1:5 ratio) general population comparison cohort as reference. Analyses were performed within 0–1-year, 0–5-year, and 0–10-year follow-up windows, for men and women separately, stratified by age group, by type of provoking VTE risk factor, and by calendar year. Results The VTE and comparison cohorts comprised 15,810 and 79,050 young adults, respectively. The incidence rate of CVD per 10,000 person-years was 25.5 (95%CI 23.2–27.7) in the VTE cohort and 11.0 (95%CI 10.3–11.6) in the comparison cohort. Adjusted HRs (comparison cohort as reference) for CVD in the VTE cohort were 7.4 (95%CI 4.3–12.8), 3.8 (95%CI 3.0–4.9), and 3.1 (95%CI 2.6–3.6) for the 0–1-, 0–5-, and 0–10-year follow-up windows, respectively. Similar findings were observed for myocardial infarction and ischemic stroke as separate outcomes and in analyses stratified by sex, age, VTE- provoking risk factors, and calendar year. Conclusion Young adults with VTE had an elevated risk of CVD compared with persons in an age- and sex-matched comparison cohort. Funding This study was supported by Department of Clinical Epidemiology, Center for Population Medicine, Aarhus University and Aarhus University Hospital, Denmark and by the Independent Research Fund Denmark (3101-00102B).