Incidence of aortic aneurysm, dissection, or rupture among patients with polymyalgia rheumatica and giant cell arteritis

Background: Patients with polymyalgia rheumatica (PMR) may have subclinical large vessel vasculitis. We compared the incidence of aortic complications in PMR and giant cell arteritis (GCA) to the general population. Methods: A retrospective cohort study was performed of patients with PMR and GCA identified by >= 2 ICD-9/ICD10-CM diagnostic codes and concurrent corticosteroid treatment in the US-based TriNetX database (2000-2024). Matched general population controls were identified (1:3 ratio). The primary outcome, aortic complications, was a composite of aortic aneurysm and dissection/rupture. Adjusted hazard ratios (aHR) were calculated using Cox proportional cause-specific hazard models with PMR as the referent category. Findings: Of 57,336 patients, 17,327 had PMR, 4,734 had GCA, and 35,275 were matched controls. Median follow-up time was 3.74 years (interquartile range, 1.8-6.4). The incidence rate of any aortic complication per 1,000 person-years was highest for GCA (11.69), followed by PMR (6.78) and the general population (5.09). Compared to patients with PMR, patients with GCA had a higher risk of any aortic complication (aHR 1.87, 95 % confidence interval (CI) 1.58-2.21); the general population risk was similar (aHR 0.95, 95 % CI 0.84-1.06). In a sensitivity analysis, patients with PMR who later developed GCA had a risk similar to those initially diagnosed with GCA (aHR 0.85, 95 % CI 0.60-1.19). Interpretation: Patients with PMR had a similar risk of large vessel complications compared to the general population and a lower risk compared to those with GCA. These results do not support screening for aortic inflammation among patients with PMR who lack features of GCA.