Antiplatelet agents in the prevention of cardiovascular morbidity and mortality in older patients with vascular disease.

摘要

Antiplatelet drugs have been demonstrated to reduce the incidence of myocardial infarction (MI), stroke or vascular death in patients with vascular disease. There are no data suggesting that antiplatelet therapy acts differently in older people than in younger people and recommendations based on randomised clinical trials are probably generalisable to older people. Aspirin (acetylsalicylic acid) has been shown to reduce the incidence of non-fatal MI, nonfatal stroke and vascular death in patients with acute MI, a previous MI, angina pectoris or peripheral occlusive arterial disease (POAD), and to reduce cardiovascular morbidity and mortality in patients with a prior ischaemic stroke or transient ischaemic attack (TIA). It has also been shown to reduce the incidence of thrombus formation after coronary artery bypass graft surgery and percutaneous transluminal angioplasty, and in patients with atrial fibrillation and heart valve replacements. Deep vein thrombosis and pulmonary embolism after surgery are also prevented by aspirin. The available data allows the following recommendations to be made. Aspirin 160 to 325 mg daily should be administered to older men and women without contraindications to aspirin who have acute MI, prior MI, unstable or stable angina pectoris, ischaemic stroke, TIA or POAD, and continued indefinitely to reduce the risk of MI, stroke or vascular death. Aspirin should be started in patients before or immediately after revascularisation, and after heart valve replacement. Older men and women with nonvalvular atrial fibrillation who have contraindications to oral anticoagulant therapy but no contraindications to aspirin should be treated with aspirin 325 mg daily. It is reasonable to treat older men and women without contraindications to aspirin with aspirin 160 to 325 mg daily if they are at high risk for developing new coronary events. The incidence of stroke, MI or vascular death in patients after a stroke or TIA is reduced by ticlopidine. Therefore, ticlopidine 250 mg twice daily may be used in older men and women with a history of stroke or TIA who do not respond to or who cannot tolerate aspirin. Patients at high risk for coronary artery stent thrombosis benefit from combined therapy with aspirin plus ticlopidine. The annual incidence of ischaemic stroke, MI or vascular death was significantly reduced by clopidogrel in the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial. Therefore, clopidogrel 75 mg daily may be used in older men and women with symptomatic atherosclerosis who do not respond to or who cannot tolerate aspirin to reduce the incidence of ischaemic stroke, MI or vascular death. It should be noted that the acquisition cost for either ticlopidine or clopidogrel is considerably greater than that for aspirin. Most data indicate that the combination of aspirin and dipyridamole is not more effective than aspirin alone in preventing vascular events, and available data do not support the use of sulfinpyrazone in patients with vascular disease.