Can I take tylenol (acetaminophen) instead of aspirin to prevent heart problems?

No. No, tylenol (acetaminophen) is antipyretic( fever reducer) and pain reliever and that's about it. It does nothing for cardiovascular system.
No. There are studies coming out tylenol (acetaminophen) might be the cause of high blood pressure aspririn helps the platelet from sticking together so it is effective for thinning blood flow. The natural Aspirin supplement is white willow bark.