Follow-up after coronary arterial reperfusion with intravenous streptokinase in relation to residual myocardial infarct artery narrowings

Abstract

Short- and long-term changes in residual stenosis of the myocardial infarct-related coronary arteries in patients with successful reperfusion by intravenous streptokinase have not been determined until now. In 15 patients the residual diameter stenosis decreased significantly from 62 ± 9% after 24 hours to 55 ± 13% in the fourth week (p < 0.005). Quantitative angiographic analyses in 61 patients with patent infarct-related coronary arteries in the fourth week revealed a mean diameter stenosis of 61 ±13%. The patients were followed up 34 ± 10 months. Sixteen had elective coronary artery bypass surgery or percutaneous transluminal coronary angioplasty (PTCA). Eighteen without coronary artery bypass surgery or PTCA had undergone repeat angiography after 26 ± 9 months. Twenty-five (41%) have had a residual diameter stenosis greater than 65% in the fourth week. A stenosis greater than 65% was found in: 4 of 5 patients with late reinfarction; 3 of 7 with 1-vessel coronary artery disease and persistent angina, compared with none of 11 with a stenosis less than 65%; 6 of 7, whose silent reocclusion had been found at long-term follow-up compared with 1 of 9 with a residual stenosis less than 65%. In 8 patients with persistent patency of the infarct artery, the stenosis had decreased significantly from 55 ± 6% to 36 ± 12% (p < 0.005). Correspondingly, there was a significant improvement in the infarct-related left ventricular wall motion disorders. These data indicate that in patients with less severe residual stenosis in the fourth week after successful intravenous strepto-kinase the long-term course is relatively uneventful, whereas reocclusion or reinfarction in the same myocardial territory is frequent in patients with a stenosis greater than 65%. PTCA may be advisable in these latter patients.