Preventing serious sequelae after an acute coronary syndrome: the consequences of thrombosis versus bleeding with antiplatelet therapy.

Acute coronary syndrome (ACS) is associated with a persistent prothrombotic state, placing patients at high risk of subsequent ischemic events. Guidelines recommend the use of dual antiplatelet therapy with aspirin + a thienopyridine (clopidogrel) for at least a year after ACS in most patients, except those who undergo coronary artery bypass grafting. Clinical studies demonstrate that this strategy significantly reduces the risk of ischemic events at the expense of a small increase in the risk of bleeding. Physicians must balance the risk of bleeding against the benefit of ischemia prevention, bearing in mind that ischemic events are generally more common than major bleeding and often associated with more catastrophic consequences or ongoing morbidity. The relationship between bleeding and mortality is complicated by the fact that many risk factors for bleeding are also those for mortality and that bleeding may lead to discontinuation of antiplatelet therapy, thereby increasing the risk for an ischemic event. Data suggest that physicians tend to overestimate the risk of bleeding and underestimate the risk of ischemia. Careful patient selection and thorough patient education are the keys to managing antiplatelet therapy after ACS, especially as newer more potent antiplatelet agents, such as prasugrel, become available.