Antithrombotic and thrombolytic therapy for ischemic stroke.

Anthithrombotic therapy is widely used as primary and secondary preventative treatment for ischemic cerebrovascular disease. Aspirin modestly reduces the risk for subsequent ischemic stroke after a transient ischemic attack or initial stroke. Adding dipyridamole may enhance this benefit. Ticlopidine confers a small additional benefit, but with more side effects and cost. The best dose of aspirin remains unsettled, but recent studies support the concept of very early initiation of treatment. Intravenous and subcutaneous heparin or low-molecular-weight heparin is not recommended because of enhanced bleeding side effects, unless venous thrombosis in debilitated patients is a concern. Thrombolytic therapy with rt-PA was recently demonstrated to improve outcome in ischemic stroke patients treated within 3 hours of onset. However, the risk-benefit ratio is narrow because of the substantial risk for intracerebral hemorrhage with rt-PA. An enhanced ability to identify patients at risk for bleeding and newer thrombolytic drugs may expand the utility of this therapy, as would extending the time window beyond the current 3-hour period. Clinicians should anticipate continued advances in the fields of antithrombotic and thrombolytic therapy for ischemic stroke over the next few years.