Clinical and Angiographic Features of Patients with an Occluded Versus a Patent Infarct Vessel After Intravenous Streptokinase for Acute Myocardial Infarction

Despite early treatment with thrombolytic agents for acute myocardial in farction, a significant portion of patients fail to achieve a patent infarct artery. To study the various factors related to achieving patency in the infarct vessel, 201 patients who received streptokinase within six hours of symptoms were studied. All patients underwent cardiac catheterization during the same hospi talization at 5.40±3.26 days after admission. Forty five (22.4%) patients were found to have an occluded infarct artery (group 1) and 156 (77.6%) had a patent infarct vessel (group 2). There was no difference in the time from onset of symp toms to receiving streptokinase between the two groups. The two groups were to each other with regard to age, gender, history of myocardial infarc tion or angina, and major risk factors for coronary disease. Coagulation pa rameters before and after streptokinase therapy, reflecting the lytic state, were similar in both groups. The left ventricular end diastolic pressure was signifi cantly higher and the left ventricular ejection fraction was significantly lower in group 1 than in group 2.

These observations suggest that despite early initiation of thrombolytic ther apy in patients with acute myocardial infarction, a significant portion of pa tients fail to achieve a patent infarct artery. This failure cannot be explained by the observed clinical parameters or the lytic state after streptokinase.