Transluminal coronary angioplasty can serve as a model for controlled coronary artery occlusion and reperfusion which enables assessment of short-term changes in collateral vessel filling in patients with severe atherosclerotic coronary artery disease. In 16 patients with isolated left anterior descending or right coronary artery disease (greater than or equal to 75% stenosis) and normal left ventricular function, collateral filling to the artery being dilated was visualized by contrast injection into the contralateral artery using a second arterial catheter. During balloon inflation, contralateral dye injection was performed as soon as the patient developed angina or ST-T changes or at 90 seconds in those patients without symptoms or signs of ischemia. Grades of collateral filling from the contralateral vessel were: 0 = none; 1 = filling of side branches of the artery to be dilated via collateral channels without visualization of the epicardial segment; 2 = partial filling of the epicardial segment via collateral channels; 3 = complete filling of the epicardial segment of the artery being dilated via collateral channels. At baseline angiography, nine patients had grade 0 collateral filling, seven had grade 1 and none had grade 2 or 3. During coronary occlusion by balloon inflation, collateral filling improved by one grade in eight patients, two grades in five patients, three grades in two patients and remained the same in one patient.(ABSTRACT TRUNCATED AT 250 WORDS)

SUMMARY Streptokinase was infused into the ischemia-related coronary artery at a rate of 1000-2000 U/min for 15-95 minutes in 29 patients with acute myocardial infarction(AMI group) and in five patients with unstable angina pectoris (UAP group). Reopening of the completely obstructed vessel or increase of diameter at the site of subtotal lesions occurred in 22 AMI patients within 15-90 minutes of streptokinase infusion. In four of these patients, antegrade flow to the distal segments of the infarct vessel was seen after intracoronary nitroglycerin or sublingual nifedipine administration, which preceded streptoklinase infusion, and in two patients, streptokinase infusion was combined with recanalization by means of a guide wire. Chest pain was alleviated after reperfusion; ejection fraction was 50.5 ± 12% before and 54.6 ± 9% immediately after successful intracoronary lysis (p < 0.05). Repeat angiography, performed 25 ± 11 days after the acute intervention in 19 AMI patients, revealed reocclusion of the infarct vessel in one patient. Aortocoronary bypass surgery was performed electively in six AMI patients at varying intervals after successful lysis. Upon intraoperative inspection, the bulk of myocardium perfused by the recanalized vessel was found to be viable.Intracoronary streptokinase infusion did not result in opening the complete obstruction or improvement of lumen at the site of subtotal lesions in seven AMI patients and in all UAP patients. The total dose of 128,000 ± 36,000 U of streptokinase resulted in only minor decrease of fibrinogen, from 451 ± 93 mg% to 430 ± 91 mg%. Bleeding from the arterial puncture site in two patients, the only complications that could be attributed to the procedure, was due to heparinization.Intracoronary streptokinase application appears to be a safe and efficient method of achieving reperfusion and alleviating ischemia in the majority of patients with acute myocardial infarction. The method was not beneficial in treating unstable angina pectoris, and its potential for salvage of myocardium is yet to be assessed.IN A PREVIOUS STUDY, coronary angiography performed in 18 medically treated infarct patients during the acute and chronic stage revealed spontaneous recanalization of the infarct vessel in 40% of the cases.' In another study, acutely occluded coronary arteries could be recanalized mechanically by use of guide wires and catheters in 10 patients.2 Repeat angiography in the chronic stage of myocardial infarction showed increases in diameter of the recanalization canal in six of these patients. Most 307Materials and Methods Study GroupThe study group consisted of 34 patients in whom acute coronary angiography was performed between June 22, 1979 and March 30, 1980. The final diagnosis of AMI (patients 1-29) and UAP (patients 30-34) was based on serial CPK4 and CK-MB5 values. These enzymes were normal in the UAP patients, but were increased to pathologic levels (peak CPK 879 ± 816 U/1) in the AMI patients. All patients were admitted to the hospital because they had ches...

Summary: In five patients with acute myocardial infarction. the effects of both intracoronary nitroglycerin (NTG) and subsequent intracoronary streptokinase application were evaluated. In addition. transluminal recanalization was performed in one of these patients. Injection of NTG into the infarct-related coronary artery resulted in improved distal filling of the subtotally occluded left circumflex artery in one patient, and in transient patency of the completely occluded right coronary artery in a second patient. In a third patient patency of the totally occluded left anterior descending artery (LAD) was achieved by transluminal recanalization with a guide wire. In a fourth patient with occlusion of the LAD. there was no response to intracoronary NTG and mechanical recanalization was not attempted. Subsequent intracoronary infusion of streptokinase (1.000-2.000 U /min for 15-60 min) resulted in a further and long-term reduction of narrowing at the site of acute occlusion in patients I-III and in opening of the completely occluded LAD in patient IV. Improvement of lumen was paralleled by alleviation of symptoms. In a fifth patient. in whom the LAD was subtotally occluded. the degree of coronary obstruction could not be changed by intracoronary application of NTG or by lysis. In this patient. symptoms and ECG changes improved with reduction of pathologically elevated blood pressure values. The findings suggest that myocardial infarction had been caused by thrombotic occlusion in four patients. and that spasm of the infarct vessel could have been an additional factor in two of these patients. In the fifth patient. an increase of afterload in the presence of a subtotal lesion might have caused the critical imbalance between oxygen supply and demand. resulting in cell death.

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We randomly assigned patients with a clinical diagnosis of acute myocardial infarction to one of four treatment groups: intracoronary streptokinase, intracoronary nitroglycerin, intracoronary streptokinase and intracoronary nitroglycerin, or conventional therapy without initial angiography. Of 124 patients 122 sustained acute myocardial infarction. Initial angiography revealed total occlusion of the coronary artery responsible for infarction in 67 per cent (61 of 91). Acute recanalization occurred in 74 per cent (32 of 43) of patients receiving streptokinase but in only 6 per cent (1 of 18) of patients treated with nitroglycerin alone (P less than 0.01). At angiography of all four groups on Day 10 to 14 the vessel responsible for acute myocardial infarction was patent in 77 per cent (71 of 92) of patients; there was no difference among groups, indicating gradual, endogenous thrombolysis in patients not treated with streptokinase. Patients with subtotal obstruction initially had significant improvement in left ventricular function, significantly lower peak creatine kinase levels, and a trend toward lower mortality than patients with total occlusion initially. Mortality at six months in patients receiving streptokinase (21 per cent, 13 of 62) did not differ significantly from that in patients not treated with streptokinase (10 per cent, 6 of 61). Additional studies will be necessary to assess treatment effects in the angiographic subsets identified by this trial.