In a review published in the British Medical Journal (Mayor S. “Risks of aspirin outweigh benefits in people without cardiovascular disease, shows analysis.” BMJ 2012; 344: e241), the risk versus benefit of taking aspirin for a preventative treatment for strokes and heart attacks was examined. Data from numerous trials revealed that aspirin is effective in reducing the number of strokes and heart attacks but also increased the risk for bleeding from the G.I. tract.
Aspirin works as an anti-platelet agent. Platelets are blood components that clump together and help stop bleeding but also aggregate around cholesterol plaques in arteries, causing blood clot (thrombus) that can lead to a heart attack or stroke.
Inhibiting platelets using aspirin on a regular basis decreases the chances of thrombus formation but also increases the risk for bleeding. The bleeding is not only from minor cuts on the skin but also internal bleeding. Aspirin can cause or contribute to ulcers of the stomach, which can produce significant and potentially life-threatening bleeding. In addition to gastric ulcers, bleeding can also include hemorrhagic strokes and post-traumatic bleeding.
In patients who have already had a stroke, transient ischemic attack (TIA), or heart attack, regularly taking aspirin (“secondary prevention”) appears to have greater benefit than risk. This is because these patients are at higher risk for recurrent event. In those without a prior vascular event (“primary prevention”), it is not so clear that aspirin benefits outweigh the risks.
The recent review found that people taking aspirin regularly for primary prevention had a 30% increase in the occurrence of serious G.I. bleeding while decreasing the risk of heart attack and stroke, but to a lesser degree. The data indicated that for every 1000 people taking daily aspirin, there were six non-fatal heart attacks prevented, but about 12 with gastrointestinal bleeding. If you translate this to millions of Americans, the risk becomes significant.
At this time, the recommendations remain that aspirin use is recommended for secondary prevention but that for general primary prevention the risks might outweigh the benefits. The use of aspirin for primary prevention should be individualized by your physician, taking into account such factors as age, sex, smoking history, diabetes mellitus, high blood pressure, high cholesterol, heart disease, or strong family history of heart attack or stroke. The benefits of aspirin appear to be different comparing men and women-aspirin has more of an impact on reducing heart attack in men and more reduction in stroke for women.
The US Preventive Services Task Force (USPSTF) recommends that if you are a man between the ages of 45 and 79, you should talk with your doctor to see if aspirin benefits for heart attack prevention outweigh the risks. If you are a woman between the ages of 55 and 79, you should talk with your doctor to see if aspirin benefits for stroke prevention outweigh the risks. The USPSTF recommends against the use of aspirin for primary prevention of heart attack in men less than 45 years of age or for stroke in women less than 55 years of age.
Where can I learn more? http://www.uspreventiveservicestaskforce.org/uspstf/uspsasmi.htm