For decades, healthy patients were told to take a low-dose aspirin as a precaution to help prevent heart problems, but the guidelines changed this year. For patients who have had a heart attack, stroke or open heart surgery, a daily aspirin is still recommended and can be a life-saver. But the blood-thinning effect from aspirin could cause a major bleeding event, so for many healthy patients, the daily aspirin habit was not worth the risk.