In Patients with Heart Failure, Allopurinol Reduces Incidence of Atrial Fibrillation
SAN FRANCISCO, CA—Allopurinol reduced the incidence of atrial fibrillation (AF) in patients with heart failure, a retrospective cohort study presented at ACC.13, the American College of Cardiology's 62nd Annual Scientific Session, has found.
Serum uric acid has recently been shown as a simple and independent marker of morbidity and mortality in heart failure as well as a predictor of atrial fibrillation risk.
“The effects could be mediated by changes in oxidative stress,” noted Fernando Enrique Hernandez, MD, from the Miami Veterans Affairs Healthcare System, and the Department of Medicine, University of Miami, Miami, FL.
Dr. Hernandez and colleagues evaluated the effect of allopurinol on incidence of AF in 603 veterans enrolled in the Bruce Carter Miami Veterans Affairs heart failure clinic between January 2005–January 2011. Patients had an ejection fraction ≤40%, and “AF was defined as being hospitalized for AF or seen in clinic visit for AF.” Allopurinol exposure was categorized as either allopurinol prescribed after the diagnosis of HF in the pharmacy's electronic medical record (categorical variable) or net time from the date of the subject's first prescription until the date of the final prescription, death, or administrative censoring.
“We used logistic regression to calculate the propensity of using allopurinol and then conducted a propensity matched analysis as well as multivariate Cox proportional models adjusted for the propensity score and left atrial size,” they stated.
The 103 patients who used allopurinol were matched with 500 non-allopurinol users. The two matched groups were similar in propensity matched baseline characteristics that included mean age, CAD, ACEI and beta-blocker use, median left atrial size and mean ejection fraction, the investigators stated.
When compared with the non-allopurinol users, incidence of AF was lower in the allopurinol group (HR 0.53 [95% CI 0.28–0.98]; P=0.04), adjusted for the propensity of using allopurinol.These findings require validation in randomized trials, the study authors concluded.