Aspirin has been shown to help prevent a second heart attack in people who have already had a heart attack. However, aspirin also causes bleeding that can kill a person, so researchers wanted to find out if the heart-attack-preventing effects of aspirin would be offset by the complications of bleeding that aspirin can cause (NEJM, August 29, 2018). The researchers studied diabetics because diabetes is among the strongest risk factors for suffering a heart attack in North America today. According to the American Heart Association (AHA), more than 68 percent of people age 65 or older with diabetes die from some form of heart disease, and 16 percent die from a stroke.
The 15,480 adult diabetics who had no obvious heart disease were placed on either 100 mg of aspirin per day (a little more than one baby aspirin) or a placebo. Over the next 4.7 years, a heart attack or clotting stroke occurred in 8.5 percent of the aspirin group, compared to 9.6 percent of the placebo group. This appears to be a significant protection, but major bleeding occurred in 4.1 percent of the aspirin group, compared to 3.2 percent in the placebo group. This is a also a significant difference and shows that whatever advantage was gained by the anti-clotting benefit of aspirin was offset by the bleeding that aspirin can cause, primarily into the brain and intestinal tract.
Data on Aspirin Preventing Heart Attacks
Taking aspirin daily for three years is associated with a small reduction in heart attacks only in people who have had previous heart attacks, but not in those who had not had a previous heart attack, and the people most likely to benefit from taking aspirin daily are those 50 to 70 years old (Clin Cardiol, May 2017;Â Am J Med, Feb 2015;128(2):137-43). The AHA recommends that you take daily aspirin only if your chance of developing a heart attack in the next 10 years is greater than five percent (Ann Intern Med, June 21, 2016;164(12):826-35). They do not recommend that most people over 70 take aspirin regularly because of the increased risk for bleeding.
Factors that put you at high risk for a heart attack include:
• A previous heart attack or stroke
• Previous heart bypass surgery
• Angina (chest pain due to coronary artery disease)
• Diabetes and at least one other heart disease risk factor such as smoking or high blood pressure
• A stent in the arteries leading to your heart. Stents increase risk for clots for the rest of a person’s life. Almost all patients with stents are prescribed some type of anti-clotting medication.
How Aspirin May Help to Prevent Heart Attacks
A heart attack and most strokes are not caused by narrowed arteries. They are caused by a sudden complete blockage of blood flow to the heart or brain. First a plaque breaks off from the inner lining of an artery leading to your heart or brain. Then that spot bleeds and a clot forms. Then the clot extends to block completely all blood flow to the heart or brain. The heart muscle then suffers from lack of oxygen and dies. Aspirin helps to prevent blood clots from forming and therefore helps prevent heart attacks and strokes. When a patient is at very high risk for forming clots, doctors often prescribe other drugs with aspirin such as clopidogrel, prasugrel or ticagrelor.
If you have sudden chest pain or headache and think that you may be having a heart attack or stroke, dial 911. You are likely to need far more treatment than just taking aspirin. Often emergency technicians do give aspirin while they are rushing you to a hospital, or after you enter an emergency room with a suspected heart attack. If you are having a stroke, aspirin can harm you because some strokes are caused by bleeding and aspirin increases bleeding.
People Who Should Not Take Aspirin
You should not start aspirin therapy without first consulting your doctor. You should not take aspirin if:
• You are at increased risk for bleeding for any reason, particularly to the stomach, intestines or brain
• You drink alcohol regularly. Taking aspirin and drinking alcohol markedly increases risk for stomach and intestinal bleeding.
• You engage in activities in which you are at risk for banging your head, which could result in bleeding into your brain
• You are allergic to aspirin
Caution About Stopping Aspirin
Never stop taking aspirin suddenly. You can suffer rebound increased risk from stopping aspirin which puts you at increased risk for a heart attack. If you are going to stop taking aspirin after taking it for a while, your doctor will tell you how to gradually taper your dose of aspirin.
Lifestyle Factors that Decrease Risk for Clots
What you eat and what you do influence your susceptibility to forming clots. You can decrease your risk for clotting by:
• losing excess weight
• exercising
• avoiding smoking and smokers
• keeping diabetes well controlled
• lowering high blood pressure
• lowering high cholesterol
• limiting salt
• following a heart-healthy diet with plenty of vegetables, fruits, whole grains, beans, nuts and other seeds
Dr. Gabe Mirkin is a Villager. Learn more at www.drmirkin.com
