[The Italian Group for the Study of Streptokinase in Myocardial Infarct: Coronarographic and ventriculographic study].

The effects of intravenous thrombolytic treatment on the reperfusion of infarct related coronary artery and left ventricular function were assessed in 251 pts. with first episode of myocardial infarction, enrolled in the G.I.S.S.I. trial, in which coronary angiography and left ventriculography have been performed within the second and third week from the onset of symptoms. A total of 251 pts. were randomized in two groups--133 treated with streptokinase (SK) and 118 controls. Among those treated with SK, in 71 (57.9%) the treatment was started within 3 hours and in 56 (42.1%) after 3 hours from the onset of symptoms. The infarct related vessel was occluded in 43 (32.3%) patients treated and in 60 (50.9%) controls (p less than 0.01). No significant difference was found in the left ventricular ejection fraction among the treated patients and controls while a significant difference resulted in the percentage of patients who had left ventricular ejection fraction greater than or equal to 50% in the group of patients with SK within 3 hours in comparison to controls. Left ventricular ejection fraction remained normal without any correlation with the type and time of the treatment, if the infarct related vessel resulted open at the coronary angiography. The study of the regional wall motion of left ventricle did not show any significant difference neither in the infarct size nor in the type and the time of treatment. In conclusion, the thrombolitic treatment with SK in acute myocardial infarction using the protocol adopted in the G.I.S.S.I. trial, obtains the reopening of infarct related vessel in an high percentage of patients; this event helps in great measure to conserve left ventricular function, especially in patients with anterior myocardial infarction if the treatment was started within the first 3 hours from the onset of symptoms.