ANGIOGRAPHIC ASSESSMENT OF THE INFARCT-RELATED RESIDUAL CORONARY STENOSIS AFTER SPONTANEOUS OR THERAPEUTIC THROMBOLYSIS

The severity of the infarct-related residual coronary stenosis after spontaneous or therapeutic thrombolysis was quantitatively assessed in 91 patients with an acute myocardial infarction who were allocated to treatment in the acute stage with either a thrombolytic agent (100 mg of recombinant tissue-type plasminogen activator given over 3 h, 49 patients) or a placebo (42 patients). Heparin and aspirin were given to both groups until angiography was performed. Digital subtracted images of the infarct-related coronary vessel were obtained 10 to 14 days after hospital admission and were subsequently analyzed with the use of a computer-assisted coronary stenosis measurement system. Neither treatment group differed significantly in age, gender or location of the culprit coronary lesion. Median values (90% range) in the thrombolysis and control groups were, respectively, 1.95 (0.9 to 5.3) mm versus 1.7 (0.9 to 3.4)mm for stenosis length; 1.4 (0.8 to 2.7) mm versus 1.4 (0.9 to 1.8) mm for minimal luminal diameter; 57% (36% to 75%) versus 58% (44% to 71%) for diameter obstruction; 82% (59% to 95%) versus 82% (68% to 92%) for geometric area obstruction; and 78% (58% to 91%) versus 79% (66% to 90%) for densitometric area obstruction. The difference between the two groups was not statistically significant for any of these measurements. Thus, in this study no significant differences in anatomy or severity of residual coronary stenosis could be demonstrated at 10 to 14 days after an acute myocardial infarction in patients with a recanalized infarct-related vessel, whether or not thrombolytic therapy was given on admission. These results indicate that with effective antithrombotic treatment, gradual endogenous fibrinolysis or more rapid lysis induced by the infusion of a thrombolytic agent results in a similar infarct-related coronary lesion at the time of hospital discharge.