Why Aspirin Prevents Heart Attacks

By Spader, Catherine, RN

That ordinary bottle of aspirin in your medicine cabinet not only treats pain and fever, it can help prevent a heart attack. Aspirin can help save your life, but it is not safe for everyone.

How Does Aspirin Prevent a Heart Attack?

Most heart attacks are caused by a blood clot that plugs up an artery—a coronary artery—in your heart. Blood clots are more likely to form when you have atherosclerosis, or hardening of the arteries. A blood clot can block blood flow to your heart muscle, depriving your heart cells of oxygen. Without immediate treatment, heart muscle begins to die, causing a heart attack (myocardial infarction). Myocardial means heart muscle and infarction means that live tissue is dying.

Platelets are cell-like substances in your blood that help your blood form a clot. Aspirin is a nonsteroidal anti-inflammatory medication. It is also an antiplatelet drug that prevents platelets from sticking together and clumping. Aspirin can prevent a heart attack by making it harder for blood clots to form.

Aspirin can help treat a heart attack in progress and can greatly improve your chance of surviving a heart attack if it is taken as soon as symptoms begin.

Who Should Take Aspirin to Prevent a Heart Attack?

Aspirin therapy has been shown to reduce the frequency of nonfatal heart attacks by 30% and fatal heart attacks by 15% in high-risk populations, according to a review on antiplatelet drugs from the American College of Chest Physicians (Source: ACCP).Your doctor may recommend aspirin therapy if you have coronary heart disease (CHD), angina (a type of chest pain caused by CHD), or if you’ve had a stroke or transient ischemic attack (TIA).

You may want to consider aspirin therapy if you smoke or if you have risk factors for CHD (and heart attack) such as:

  • High cholesterol

  • Diabetes

  • High blood pressure

  • Family history of heart attack or stroke

What Are the Side Effects of Aspirin?

Aspirin is generally safe to take occasionally for pain or fever. However, daily use of aspirin, even in low doses, can have serious side effects because it is a general inhibitor of blood clotting all over your body. Daily use of aspirin is known to cause the following side effects:

  • Hearing problems, such as ringing in the ears (tinnitus) and even hearing loss. Aspirin appears to affect the mechanics of hearing. The hearing loss is reversible.

  • Stomach ulcer, which can bleed heavily and be difficult to stop

  • Stroke caused by bleeding in the brain. This type of stroke is a hemorrhagic stroke, which is different than a stroke caused by a blood clot.

In addition, if you are allergic to aspirin, an allergic reaction can be serious or life threatening, even after a small dose of aspirin. If you are prone to allergies, particularly medication allergies or sensitivities, you may want to take your first aspirin in your doctor’s office in case of complications.

Who Should Not Take Aspirin?

It’s best to delay a daily aspirin regimen for heart attack prevention until you’ve talked with your doctor. Your doctor may tell you not to take aspirin or to stop your aspirin therapy for the following reasons:

  • Ulcer in your stomach or small intestine

  • Heavy drinking. This means more than two drinks per day if you are a man or one if you are a woman. Alcohol increases your risk of stomach bleeding when you take aspirin.

  • Liver disease or a bleeding disorder

  • Risk factors for hemorrhagic stroke

  • Upcoming medical or dental procedures

  • Younger than 21 years of age (due to the risk of Reye syndrome)

How Should I Take Aspirin to Prevent a Heart Attack?

To prevent a heart attack, you need a smaller dose of aspirin than the amount you take for a fever or headache. For fever or headache you take about 650 mg, or two adult-size aspirin. In general, a smaller dose of aspirin is considered 75mg to 325 mg a day, or one adult-size aspirin. If you have already had a heart attack your daily dose may be larger. Sometimes doctors recommend using enteric-coated aspirin. The coating can help prevent bleeding in your digestive tract. Your specific dose and form of aspirin depend on your particular risk factors and underlying medical conditions.

If you are having chest pain or other symptoms of a heart attack, such as dizziness or shortness of breath, call 911 immediately. The operator will most likely tell you to chew one non-coated 325 mg tablet. An enteric-coated tablet will act slowly even if chewed.

Medical Reviewer: McDonough, Brian, MD Copyright: © Copyright 2012 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

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