Late results after intracoronary thrombolysis and early bypass grafting for acute myocardial infarction

Abstract

Successful thrombolysis for acute myocardial infarction reduces early mortality. For definite correction of the underlying arteriosclerotic lesion, invasive treatment is mandatory. Early bypass grafting has been performed in 70 patients with an ischemic interval of less than 4 hours before reperfusion by thrombolysis. Surgery was undertaken an average of 4.5 days after the streptokinase administration. The hospital mortality rate was 1.4%. At 8 years the actuarial survival rate was 88% and the complication-free survival rate, 84%. At the latest follow-up study, 90% of the patients were in functional class I or II. Because of advanced age, 37% of the survivors have retired and 29% are working. Thirty-four percent did not return to work after the operation. In 24 patients a transmural needle biopsy specimen was taken at operation to study the extent of ischemic damage. Surprisingly, the extent of necrosis did not correlate with the ischemic interval (r = 0.17), whereas enzyme activity and extent of necrosis did correlate (r = 0.76). Late angiography was done in 44 patients (56%). The correlation between ischemic interval and regional wall motion score was weak when the whole group was considered (r = 0.35), but 70% of the patients with an ischemic interval of less than 3 hours had normal or near normal regional wall motion. In patients with prolonged ischemia, distribution between normal function and severe damage was uniform. In patients with ultrastructural and wall motion studies, early necrosis and late left ventricular function correlated fairly well (r = 0.69). We conclude that additional early bypass grafting after successful thrombolysis yields excellent long-term clinical results, especially in patients with an ischemic interval of less than 3 hours.