To assess the relative risk of myocardial infarction (MI) and ischemic stroke in patients with newly diagnosed granulomatosis with polyangiitis (Wegener's) (GPA) compared with that in controls from the general population.
Using a population-based database from the province of British Columbia, Canada, we conducted a matched cohort study in which each patient with incident GPA was matched for age, sex, and entry time with up to 10 individuals from the general population. Patients in the GPA cohort were required to have received at least 1 prescription for oral glucocorticoids, methotrexate, cyclophosphamide, leflunomide, azathioprine, cyclosporine, mycophenolate mofetil, or rituximab within 1 month before or 6 months after the index date. We compared the incidence rates of MI and ischemic stroke between the 2 groups and calculated hazard ratios (HRs), adjusting for confounders.
Among 504 patients with incident GPA (53.4% female, mean age 57.4 years), MI developed in 23 patients, and ischemic stroke developed in 18 patients (incidence rates of 11.7 per 1,000 person-years and 8.9 per 1,000 person-years, respectively). The incidence rates among 5,222 subjects without GPA were 5.2 per 1,000 person-years and 4.3 per 1,000 person-years, respectively. The multivariable HRs among GPA patients were 1.86 (95% confidence interval [95% CI] 1.05-3.31) for MI and 1.50 (95% CI 0.78-2.89) for ischemic stroke. The age-, sex-, and entry time-matched HR for cardiovascular disease (composite outcome of MI or stroke) was highest during the first year after GPA diagnosis (HR 2.88, 95% CI 1.37-6.08).
Patients with GPA have a significantly increased risk of MI and a non-statistically significant trend toward an increased risk of ischemic stroke. Monitoring for this complication and vigilance in modifying risk factors are particularly warranted in this patient population, especially early after the diagnosis of GPA.