[Thrombolysis in unstable angina].

Anatomical, coronary angiographic and angioscopic observations have revealed the frequent presence of a thrombus in the lumen of the artery responsible for ischemia in patients suffering from labile angina. A thrombus is more frequently found if coronary angiography is carried out within a few hours of angina-type pain, and its presence is a factor predicting complications (infarction, sudden death, necessity for revascularization). These observations constitute the basis of clinical trials of thrombolytic agents administered by intracoronary or intravenous route. The thrombolytic treatment does not reduce the incidence of the angina attacks (defined clinically or electrically), nor that of infarction; it produces little or no reduction (15%) in the degree of stenosis. Although lysis of the thrombus is achieved in most cases and is accompanied by immediate clinical improvement, it does not forecast the outcome in the following days. Clinical deterioration may occur, even when thrombolysis has been effective and accompanied by an improvement in the angiographic images.