[Residual stenosis following successful selective lysis of complete thrombotic coronary artery occlusion in acute myocardial infarct].

After successful lysis of a thrombotic coronary obstruction in acute myocardial infarction, both PTCA and bypass surgery can be useful in preventing reocclusion and providing long-term success in selected patients. One condition to perform such measures is a high degree of residual narrowing at the previous site of occlusion. Other investigations concerning the extent and further development of these lesions are methodically inhomogenous and different in their results. Following successful intracoronary lysis of a complete thrombotic occlusion, the remaining stenosis was measured in 106 patients using at least 2 angiographic projections both immediately after reperfusion, and 3 days later. The degree and development of the residual lesion were analysed with special regard to its anatomy and to the occlusion time. During the observation period, no mechanical intervention (PTCA) or bypass surgery took place. The 1st angiogram after thrombolysis revealed an average cross section stenosis of 90.5 +/- 6.2%, which decreased up to the control angiogram to 86.3 +/- 10.6% (p less than 0.05). In only 16 cases there was an improvement of 10% or more, in fact it was not relevant (less than 10%) in 66 patients, and in 24 a slight increase in residual narrowing could even be found. The decrease of eccentric (-5.5 +/- 9.2%) and concentric (-3.3 +/- 5.7%) lesions was not statistically different. Stenoses up to 5 mm of length (-5.7 +/- 7.2%), between 5 and 10 mm (-3.4 +/- 6.7%), and over 10 mm (-4.4 +/- 8.2%) again did not differ significantly. There was no linear correlation between degree of stenosis and total time of occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)