Non surgical coronary artery recanalization in acute transmural myocardial infarction.

Abstract

In 41 consecutive patients with an acute transmural myocardial infarction (AMI) admitted within 3 h after the onset of symptoms, the occluded coronary artery was recanalized by an intracoronary infusion of streptokinase (SK) (2000 Us/min). SK infusion was preceded by an intracoronary injection of 0.5 mg nitroglycerin to rule out coronary artery spasm, an attempt to recanalize the vessel mechanically with a flexible guidewire and an intracoronary injection of plasminogen (500 U) 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 2 patients. In 30 patients (73%), the occluded coronary artery was successfully recanalized within 1 h (mean 29 .+-. 15 min), 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 1 patient, contrast injection in 7 patients and guidewire perforation in 4 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 3 patients with cardiogenic shock. Recanalization did not prevent myocardial infarction, as shown by new Q waves and/or R-wave reduction in 24 of the 30 patients and by the rise in serum CPK [creatine phosphokinase] with an early peak, indicating CPK washout by coronary artery reperfusion. Repeat angiography 7-21 days later revealed a patent coronary artery in 12 of 15 successfully recanalized patients. The left ventricular ejection fraction had significantly improved, from 37 .+-. 5% to 47 .+-. 4%. Failure of recanalization in 11 of 41 patients may be explained by the absence of coronary artery thrombosis or poor SK penetration of the thrombus because of its distal location or SK runoff into nonaffected arteries. In patients with acute myocardial infarction the occluded coronary artery can be rapidly recanalized in 73% of the patients by an intracoronary infusion of streptokinase.