Stopping aspirin may raise risk for non-fatal heart attacks in heart disease patients

People with heart disease who quit their low-dose aspirin regimens are at increased risk of non-fatal myocardial infarction compared with those who remain compliant, a British study concluded.

To evaluate the risk of myocardial infarction and death from coronary heart disease after stopping low-dose aspirin (75 to 300 mg/d), researchers conducted a nested, case-control study of 39,513 patients ages 50 to 84 years with a first prescription for aspirin for secondary prevention of cardiovascular outcomes in 2000 through 2007.

The population was drawn from The Health Improvement Network (THIN) database, which has data on more than 3 million patients enrolled in primary care practices in the United Kingdom. Results appeared online at BMJ on July 19. Individuals were followed for a mean of 3.2 years.

During follow-up, there were 2,869 deaths from all causes, 876 non-fatal myocardial infarctions and 346 deaths from coronary heart disease. People who had recently stopped taking aspirin had a 60% increased risk of non-fatal myocardial infarction (rate ratio [RR], 1.63, 95% CI, 1.23 to 2.14) and an approximate 40% increased risk of non-fatal myocardial infarction or death from coronary heart disease (RR, 1.43; 95% CI, 1.12 to 1.84). For every 1,000 patients, there were about four more cases of non-fatal myocardial infarction per year among patients who'd recently stopped taking low-dose aspirin.

The authors noted that half of all people prescribed a low-dose aspirin regimen become non-compliant after a few years. They called for future studies to determine whether encouraging patients to continue low-dose aspirin prophylactically would decrease non-fatal myocardial infarction.