Acute myocardial infarction risk in multiple sclerosis and neuromyelitis optica spectrum disorder: A nationwide cohort study in South Korea.

Background: The link between neuromyelitis optica spectrum disorder (NMOSD) and cardiovascular disease is currently unclear.

Objective: To determine the acute myocardial infarction (MI) risk in patients with MS and NMOSD.

Methods: This study analyzed the Korean National Health Insurance Service database between January 2010 and December 2017. The included patients comprised 1503/1675 adults with MS/NMOSD who had not experienced ischemic heart disease or ischemic stroke at the index date. Matched controls were selected based on age, sex, and the presence of hypertension, diabetes mellitus (DM), and dyslipidemia.

Results: The risks of developing MI were 2.61 (hazard ratio (HR), 95% confidence interval (CI) 1.73-3.95) and 1.95 (95% CI = 1.18-3.22) times higher in MS and NMOSD compared with the control populations. Patients with NMOSD had a similar MI risk compared with patients with MS, after adjusting for age, sex, income, hypertension, DM, and dyslipidemia (HR = 0.59, 95% CI = 0.34-1.02,  = 0.059). Among each patient group, the MI risk did not differ significantly with age (20-39, 40-64 or ⩾65 years), sex, or the presence of hypertension, DM, or dyslipidemia.

Conclusion: The MI risk increased in MS and NMOSD and seemed to be comparable between NMOSD and MS.