SUMMARY In 41 consecutive patients with an acute transmural myocardial infarction (AMI) admitted within 3 hours after the onset of symptoms, we tried to recanalize the occluded coronary artery by an intracoronary infusion of streptokinase (SK) (2000 units/min). SK infusion was preceded by (1) an intracoronary injection of 0.5 mg nitroglycerin to rule out coronary artery spasm, (2) an attempt to recanalize the vessel mechanically with a flexible guidewire, and (3) an intracoronary injection of plasminogen (500 units) to increase the efficacy of the subsequent SK infusion. Coronary angiography revealed a total coronary artery occlusion in 39 patients and a subtotal occlusion in two patients. In 30 patients (73%), the occluded coronary artery was successfully recanalized within 1 hour (mean 29 ± 15 minutes), resulting in prompt contrast filling of the previously occluded vessel. An arteriosclerotic stenosis always remained at the site of the occlusion. Nitroglycerin opened the occluded coronary artery in one patient, contrast injection in seven patients and guidewire perforation in four of the 15 patients, in whom it was attempted. In 18 patients the occluded coronary artery was recanalized by intracoronary SK infusion alone. After the initial opening of the occluded coronary artery, subsequent SK infusion markedly reduced the degree of stenosis and visible thrombi disappeared. Clinically, recanalization was associated with significant relief of ischemic chest pain.None of the successfully recanalized patients died, including three patients with cardiogenic shock. ST-segment elevation was present on the ECG with no changes in the QRS complexes.Informed consent for recanalization was obtained from the patient and his relatives; in patients in cardiogenic shock, consent was obtained only from the patient's relatives.
ProtocolRecanalization was performed on a 24-hour basis. In preparation for the procedure, patients with cardiogenic shock were intubated and artificially ventilated. The patients were heparinized with 10,000 units as a i.v. bolus. To avoid significant bradycardia during coronary angiography, in most patients a pacing catheter was placed in the apex of the right ventricle. In patients with left-heart failure, a Swan-Ganz catheter was advanced to the pulmonary artery. The coronary artery judged to be occluded, based on the distribution of ST-segment elevation on the ECG, was catheterized by a second investigator using a #8F Judkins catheter. In most cases, the "infarct-vessel" was easy to recognize and was either totally or subtotally occluded. The acute nature of a total occlusion was often characterized by a poor washout of the contrast medium (meglumine and sodium diatrizoate) from the area proximal to the occlusion. A