Background: Ankylosing spondylitis (AS) is a chronic inflammatory arthritis affecting the spine in young adults. It is associated with excess cardiovascular and cerebrovascular morbidity.
Objective: To determine whether patients with AS are at increased risk for cardiovascular and cerebrovascular mortality.
Design: Population-based retrospective cohort study using administrative health data.
Setting: Ontario, Canada.
Patients: 21 473 patients with AS aged 15 years or older and 86 606 comparators without AS, matched for age, sex, and location of residence.
Measurements: The primary outcome was a composite of cardiovascular and cerebrovascular death. Hazard ratios (HRs) for vascular death were calculated; adjusted for history of cancer, diabetes, dementia, inflammatory bowel disease, hypertension, chronic kidney disease, and peripheral vascular disease; and, among those aged 66 years or older, relevant drug therapies. Independent risk factors for vascular mortality were identified in patients with AS.
Results: The mean age of patients with AS was 46 years, and 53% were male. Patients and comparators were followed for 166 920 and 686 461 patient-years, respectively. Adjusted HRs for vascular death in AS were 1.36 (95% CI, 1.13 to 1.65) overall, 1.46 (CI, 1.13 to 1.87) in men, and 1.24 (CI, 0.92 to 1.67) in women. Significant risk factors for vascular death were age; male sex; lower income; dementia; chronic kidney disease; peripheral vascular disease; and, among patients aged 65 years or older, lack of exposure to nonsteroidal anti-inflammatory drugs and statins.
Limitation: Diagnosis codes for AS were not validated in Ontario.
Conclusion: Ankylosing spondylitis is associated with increased risk for vascular mortality. A comprehensive strategy to screen and treat modifiable vascular risk factors in AS is needed.
Primary funding source: The Arthritis Program, University Health Network, Toronto; and The Arthritis Society, Canada.