Thrombolytic therapy in unstable angina pectoris new aspects in chronic refractory patients

Antithrombotic therapy is the mainstay of conservative treatment for unstable angina in patients with coronary artery disease. Platelet aggregation inhibitors and anticoagulants have led to marked reductions of cardiovascular endpoints like >>acute CABG or acute PTCA<<, >>acute myocardial infarction<< and >>cardiovascular death<<. In contrast results on the effectiveness of thrombolytic therapy are contradictory and some investigations have even demonstrated an increase of cardiovascular events, which has been attributed to various prothrombotic mechanisms. Therefore the different studies on thrombolytic therapy in unstable angina are reviewed in respect to the relationship of side effects and dosage of the substance used,vith special reference to,,tissue-type plasminogen activator<< (t-PA). It can be demonstrated, that low concentrations of t-PA (mg/kg) given for a prolonged time interval lead to a beneficial therapeutic effect in comparison to a regimen of a high concentration applied over a short time period. These findings are further supported by results of chronic-intermittent urokinase therapy in patients with chronic refractory angina pectoris. Therefore low-dose thrombolytic therapy in unstable angina pectoris can only be regarded as relative contraindication. Low-dose regimens are justified in patients with unstable angina pectoris, who remain symptomatic despite maximal medical treatment and in whom invasive procedures cannot be performed for logistic reasons, as well as in patients with chronic refractory angina pectoris.