Low dose aspirin can lower the risk of heart attacks in people without a history of heart disease by about 20%, but it does not lower the death rate or the risk of stroke. Also, there is the added risk of GI bleeding secondary to aspirin use. The risk for getting a heart attack in primary prevention is lowered from 2.3% to 1.8%, which comes to a 20% lower risk of having a heart attack. How impressive this number is depends on how you look at the numbers!
