[Low-dose aspirin in the long-term treatment of the patient with ischemic heart disease].

Coronary atherosclerosis is the process underlying virtually all the clinical manifestations of ischemic heart disease. When ulcer or fissure in the fibrous cap of the atheroma occur, platelet adhesion to subendothelium, aggregation and further platelet recruitment culminate in thrombus formation. These mechanisms are known to be responsible for most cases of acute events in patients with ischemic heart disease. Inside platelets, aspirin blocks the synthesis of thromboxane A2 by irreversibly inhibiting cyclooxygenase. Aspirin is recommended not only for treatment of patients with acute coronary syndromes (unstable angina, acute myocardial infarction), but also for secondary prevention of vascular events in chronic coronary syndromes. Aspirin prevents myocardial infarction in patients with chronic stable angina and reduces mortality, reinfarction and stroke in survivors of an acute myocardial infarction. Aspirin, alone or in combination with dipyridamole, prevents early and late occlusion of aortocoronary vein grafts. It is useful also in patients undergoing coronary angioplasty. Such benefits extend to all patients regardless of age, sex, history of hypertension or diabetes. Higher daily doses (900-1500 mg) are not more effective than lower doses (75-325 mg). Other antiplatelet drugs are not more effective than aspirin, which has the best risk-to-benefit and cost-to-benefit ratios. Ticlopidine is a reasonable alternative for use in preventing vascular events among patients intolerant to aspirin. Warfarin is an effective antithrombotic alternative to aspirin for secondary prevention after a myocardial infarction. However aspirin is easier to administer and follow-up when compared with warfarin. Warfarin should be preferred in high risk patients with left ventricular dysfunction with or without a mural thrombus, and those with associated atrial fibrillation.