Aspirin was already known as the “miracle drug” for its pain-relieving properties when researchers discovered in the early 1970s that it also offers many benefits to heart patients. Research conducted since then has confirmed that aspirin prevents first and second heart attacks, strokes and other cardiovascular events in people with cardiovascular disease (e.g., coronary artery disease or high blood pressure).

Aspirin works by inhibiting the blood’s ability to clot. It does this by interfering with the action of platelets, a component of blood that is involved in the formation of blood clots. Aspirin has also been shown to inhibit pro-inflammatory chemicals, which in turn may inhibit the development of atherosclerosis, or “hardening of the arteries.”

Because of its wide-ranging benefits, aspirin is recommended for many heart and stroke patients, including patients who have suffered from a heart attack, ischemic stroke or a kind of chest pain called angina. In addition, aspirin may be recommended for patients who have undergone coronary artery bypass surgery. In these cases, aspirin has been shown to reduce the chance of death by vascular disease. It is also recommended for victims undergoing heart attacks. Numerous studies have shown that patients who take an aspirin within 30 minutes after their heart attack begins may limit the damage of the attack. Experts recommend chewing aspirin rather than swallowing a tablet whole to achieve a faster effect.

Stroke patients, however, should take aspirin only under the advice of a physician because aspirin may aggravate certain kinds of stroke. Aspirin may increase the risk of another type of stroke (hemorrhagic) that is caused by bleeding into and around the brain, especially in women.

The decision to administer aspirin therapy as a preventive measure should be made by a physician. Various groups, including the American Heart Association, the American College of Cardiology and the United States Preventive Services Task Force have issued guidelines for the use of aspirin as a preventive measure for heart attack and stroke. In general, only patients at a reasonably elevated risk of suffering a heart attack, as judged by their coronary risk profile, are considered candidates for regular aspirin therapy. Even among these patients, however, studies have shown that aspirin therapy is probably underused, especially among women.

Although it is widely tolerated, aspirin may have serious side effects, including an increased risk of bleeding or gastrointestinal problems. It is estimated that about 30 percent of total drug-related hospitalizations are caused by aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs).

Aspirin should never take the place of medications or other treatments prescribed by a physician. People are encouraged to speak with their physician about whether aspirin would be helpful for them and, if so, what dosage the physician feels is appropriate.