One of the least expensive medications is one of the most important in preventing heart attacks. Daily low dose aspirin (81 mg) will help prevent blockage of a coronary artery, reducing the risk of myocardial infarction. It’s hard for me to believe, but many patients will stop taking a daily aspirin even if they have already had a heart attack. An article in the British Medical Journal found that one-half of patients prescribed a low-dose aspirin regimen become non-compliant after a few years. 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. 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.
Not every patient should take a daily aspirin, since there are some risks associated with it. A physician will help decide if the benefits outweigh the risks. There are few medications that are as inexpensive or effective. (Here’s a clinical pearl: don’t buy the warehouse size bottles of aspirin. If you buy a bottle of 500 pills, 400 will probably need to be discarded. If you smell vinegar, the pills are starting to break down – throw them out.)
BMJ 2011; 343:d4094