ANGIOPLASTY OF COMPLEX LESIONS IN ISCHEMIC REST ANGINA - RESULTS OF THE THROMBOLYSIS AND ANGIOPLASTY IN UNSTABLE ANGINA (TAUSA) TRIAL

Objectives. This study sought to analyze the role of complex lesion mo rphology on the acute results of angioplasty. Background. Acute compli cations of angioplasty are higher in unstable than in stable angina. T he unstable culprit lesion is usually complex, indicative of plaque di sruption and thrombus formation. Previous nonrandomized studies have s hown that the presence of intracoronary thrombus increases morbidity a fter coronary angioplasty. The role of complex morphology in coronary angioplasty outcome was studied in a prespecified subgroup analysis of a large multicenter coronary angioplasty trial. Methods. The results of coronary angioplasty from the Thrombolysis and Angioplasty in Unsta ble Angina (TAUSA) trial were analyzed. This large trial randomized 46 9 patients in double-blinded manner to receive either intracoronary ur okinase or placebo during coronary angioplasty of the culprit lesion i n ischemic rest angina with or without recent infarction. The study pr esented here analyzes in detail the results of coronary angioplasty in complex versus simple lesions in the urokinase and placebo groups. Co mplex lesions were defined before angioplasty by a core laboratory as having one or more of the following: irregular borders, overhanging ed ges, ulcerations or intraluminal filling defects proximal or distal to the lesion. Results. Of the 469 patients, 458 had identifiable culpri t lesions, of which 245 were complex and 213 were simple. Complex lesi ons were associated with a higher abrupt closure rate than simple lesi ons (10.6% vs. 3.3%, respectively, p < 0.003). Patients with complex l esions also had higher recurrent in-hospital angina (p < 0.02) and eme rgent bypass surgery (p < 0.02). Further analysis of complex lesions r evealed that abrupt closure was particularly high in the urokinase gro up (15.0% vs. 5.9% for the placebo group, p < 0.03), and most abrupt c losures were thrombotic. Composite clinical end points were also signi ficantly higher with complex lesions and urokinase. In the placebo gro up, complex lesions had a higher abrupt closure rate as well as post-c oronary angioplasty filling defects, but clinical end points were not significantly different. Conclusions. Complex lesions before coronary angioplasty increase acute complication rates after coronary angioplas ty. Urokinase as administered in the TAUSA trial had significant adver se effects, especially in complex lesions. However, even in the placeb o arm, complex lesions were associated with higher complication rates than simple lesions. Newer antithrombotic measures that particularly t arget the platelet may eventually decrease complication rates in these lesions.