RESIDUAL STENOSIS AFTER SUCCESSFUL INTRACORONARY THROMBOLYSIS OF COMPLETE CORONARY OBSTRUCTIONS IN ACUTE MYOCARDIAL-INFARCTION

  • 1 January 1985
    • journal article
    • research article
    • Vol. 74  (9) , 519-524
Abstract
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 analyzed 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 < 0.05). In only 16 cases there was an improvement of 10% or more, in fact it was not relevant (< 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. Thus, immediately after successful intracoronary thrombolysis, there is still a high degree of residual stenosis. Despite a small but statistically significant decrease it usually remains hemodynamically important. The amount of increase or decrease of narrowing cannot be predicted from total time of occlusion nor from the anatomy of the lesion. Thus, patients with a high degree of residual stenosis should be referred to PTCA or bypass surgery as soon as possible, according to other criteria such as time of occlusion and ventricular function.