Aspirin, antioxidants showed no benefit in preventing CVD development in diabetes

Aspirin and antioxidant therapy combined or alone were not superior to placebo in reducing the development of cardiovascular events in patients with diabetes and asymptomatic peripheral arterial disease, according to recent findings.

Researchers from the University of Dundee, Glasgow Royal Infirmary and other sites in Scotland, conducted the Prevention of Progression of Arterial Disease and Diabetes (POPADAD). The study included 1,276 patients with type 1 or type 2 diabetes and an ankle brachial pressure index ≤0.99 and no symptomatic cardiovascular disease. Patients were aged 40 years or older.

Patients were randomly assigned 100 mg aspirin plus antioxidant (n=320), aspirin plus placebo (n=318), antioxidant plus placebo (n=320) or placebo plus placebo (n=318) daily. Primary outcomes were death from coronary heart disease or stroke, non-fatal myocardial infarction or stroke or amputation above the ankle for critical limb ischemia and death from CHD or stroke, according to the researchers.

One hundred and sixteen of 638 primary events occurred in the aspirin groups compared with 117 of 638 in the no aspirin groups (18.2% vs. 18.3%; HR=0.98). The researchers reported 43 deaths from CHD or stroke in the aspirin groups compared with 35 in the no aspirin groups (6.7% vs. 5.5%; HR=1.23).

In the antioxidant groups 117 of 640 primary events occurred compared with 116 of 636 in the no antioxidant groups (18.3% vs. 18.2%; HR=1.03). Forty-two deaths occurred from CHD or stroke in the antioxidant groups compared with 36 deaths in the no antioxidant groups (6.6% vs. 5.7%; HR=1.21).

“We found no evidence to support the use of either aspirin or antioxidants in the primary prevention of cardiovascular events and mortality in people with diabetes,” the researchers wrote.

However, they recommended the use of aspirin for secondary prevention of cardiovascular disease in patients with diabetes.

BMJ. 2008;337:a1840.