CLINICAL AND ANGIOGRAPHIC PREDICTORS OF IMMEDIATE RECOIL AFTER SUCCESSFUL CORONARY ANGIOPLASTY AND RELATION TO LATE RESTENOSIS

The effect of immediate recoil on the results of balloon angioplasty w as examined in a group of 416 patients (596 lesions) who underwent suc cessful coronary angioplasty. Immediate recoil was responsible for los s of 0.42 +/- 0.64 mm from the potentially achievable lesion diameter, and represented 23% of the actual gain in diameter. The immediate rec oil was determined mainly by the degree of arterial stretch, which is best represented by the balloon to normal artery size ratio (correlati on coefficient 0.49, p < 0.0001). Classic risk factors for coronary ar tery disease did not affect immediate recoil, except for a trend towar d lower values in patients with history of hypercholesterolemia. There was a tendency for lower recoil in patients with residual coronary th rombus and in those who underwent angioplasty within 1 week of acute m yocardial infarction. Recoil was larger in the left anterior descendin g artery than in the circumflex or the right coronary artery. Patients with more immediate recoil developed more restenosis (>50% stenosis a t follow-up). However the late loss of luminal diameter due to the res tenotic process was smaller in those who had larger initial recoil. It is concluded that immediate recoil after balloon angioplasty is an el astic phenomenon that is related mainly to the degree of arterial stre tch. The relative importance of immediate recoil in determining the la te outcome of coronary angioplasty is at least as important as the lat e restenotic process.