Allopurinol use in patients with gout was associated with decreased risk of a first-ever acute coronary syndrome (ACS) event, according to findings from a Swedish population-based study comprising nearly 20 000 adults.
Study authors, presenting during the American College of Rheumatology Convergence 2022 meeting, report that exposure to allopurinol 100 mg and >100 mg was linked with significantly lower odds for first occurrence of an ACS event and that the greater exposure was associated with lower odds than the 100 mg.
As context for their investigation the authors cite a growing body of evidence suggesting that beyond the association of gout with increased risk of cardiovascular disease, the inflammatory arthritis caused by hyperuricemia may be an independent risk factor. Less well understood, however, is whether the use of allopurinol alters this risk which was the question that drove their research.
The team accessed data from both national and regional population-based registries in western Sweden and identified all patients between 2000-2017 with a first ICD-coded diagnosis for gout and no prior exposure to allopurinol. Potential participants with history of coronary heart disease were excluded.
The primary outcome of interest was occurrence of a first-ever ACS event, according to the study abstract. The investigators initiated follow-up at the first ICD-coded diagnosis for gout and ended after either the outcome event, death, emigration, or the end of study on December 31, 2017.
For the purposes of the study, allopurinol exposure was defined as none (no dispensed prescription within 125 days from the end of follow-up; reference group), 100 mg, or >100 mg, according to the last dispensed prescription within 125 days from the end of follow-up.
The team used logistic regression models with adjustments for age, sex, education level, comorbidity index, dispended prescriptions for cardiovascular drugs, anticoagulants/platelet aggregation inhibitors, and/or cortisone within 6 months from the end follow-up, and follow-up time.
The final cohort numbered 19 054 and two-thirds (67%) were men. Overall, women were older than men in all exposure categories and being prescribed allopurinol was associated with older age, longer follow-up time, and more comorbidities.
According to the study abstract, odds ratios (OR) for first-ever ACS events were significantly lower in both allopurinol exposure groups vs participants not exposed to the drug in the entire cohort (OR, 0.72; 95% CI, 0.59-0.88; and OR, 0.54; 95% CI, 0.40-0.72, respectively) as well as in men only (OR, 0.72; 95% CI, 0.57-0.92; and OR, 0.57; 95% CI, 0.40-0.79, respectively).
Among women treated with allopurinol, the odds of a first ACS event were not uniform. The study found that exposure to >100 mg was linked to a significantly lower OR for a first-ever event (OR, 0.46; 95% CI, 0.25-0.85), however exposure to 100 mg was not (OR, 0.72; 95% CI, 0.50-1.02).
The higher allopurinol exposure, investigators found, was associated with lower OR for first-ever ACS event than the 100 mg exposure in both men and women. Finally, across the cohort, the risk of a first-ever ACS event was similar in men and women.
“Current allopurinol use was associated with significantly lower risk of first-ever ACS event in patients with incident gout in a dose-dependent fashion, suggesting a protective effect for allopurinol,” the authors wrote. “The effect of allopurinol was similar in men and women.”
Reference: Drivelegka P, Jacobsson L, Bengtsson K, Dehlin M. Allopurinol use and risk of acute coronary syndrome in patients with incident gout: a population-based study in Sweden. Arthritis Rheumatol. 2022;74 (suppl 9).