Allopurinol has little benefit in cardiac syndrome X

(HealthDay)—Allopurinol does not appear to improve exercise capacity or peripheral endothelial or coronary function in patients with cardiac syndrome X, according to a study published online Oct. 28 in Cardiovascular Therapeutics.

Tiong Keng Lim, M.D., from National Heart Centre Singapore, and colleagues randomized 19 patients with cardiac syndrome X (mean age 59 years) to six weeks of treatment with either allopurinol (600mg/day) or placebo. Patients were crossed over to the other study arm after a four-week washout period.

The researchers found that allopurinol significantly reduced serum uric acid levels versus placebo. There was no significant difference in maximum exercise time, coronary flow reserve, or flow-mediated vasodilatation of the brachial artery between the allopurinol and placebo groups. However, there was a trend toward allopurinol reducing serum B-type natriuretic peptide compared with placebo (P = 0.07).

"In patients with cardiac syndrome X, high dose allopurinol did not improve exercise capacity, coronary or peripheral endothelial function," conclude the authors.