Risk of Arterial Cardiovascular Diseases in Patients with Multiple Sclerosis: A Population-Based Cohort Study

Background: Patients with multiple sclerosis (MS) may have a higher risk of cardiovascular diseases (CVD) than the general population, but data are limited. Methods: We conducted a population-based cohort study involving Danish citizens diagnosed with MS (n = 13,963) from 1977 to 2006 and an age- and sex-matched population cohort (n = 66,407) using data on MS, arterial CVD and comorbidity from the Danish National Registry of Patients. We calculated the risk of arterial CVD for all subjects and computed adjusted incidence rate ratios (IRRs). Results: During the first year of follow-up, the risk of myocardial infarction (MI) was 0.2% among patients with MS (adjusted IRR = 1.84; 95% confidence interval, CI: 1.28–2.65, compared with population cohort members), whereas the 1-year risk of overall stroke was 0.3% (adjusted IRR = 1.96; 95% CI: 1.42–2.71). IRRs were 1.92 (95% CI: 1.27–2.90) for heart failure and 0.77 (95% CI: 0.42–1.39) for atrial fibrillation/flutter. During the subsequent 2–30 years of follow-up, IRRs remained elevated for overall stroke (1.23; 95% CI: 1.10–1.38) and heart failure (1.53; 95% CI: 1.37–1.71) but decreased for acute MI (1.10; 95% CI: 0.97–1.24). Conclusion: In this Danish cohort, the risk of CVD among MS patients was low, but greater than that in the general population, particularly in the short term.