ANALYSIS OF LATE LUMEN NARROWING AFTER EXCIMER LASER-FACILITATED CORONARY ANGIOPLASTY

Objectives. The purpose of this study was to analyze the quantitative angiographic factors affecting restenosis after excimer laser-facilitated coronary angioplasty. Background. Restenosis after balloon angioplasty, directional atherectomy and coronary stenting has been analyzed using both dichotomous (greater than or equal to 50% diameter stenosis) and continuous (late lumen narrowing) end points, leading to the conclusion that achieving a large lumen diameter at the time of the procedure is associated with a lower risk of angiographic restenosis. Methods. Quantitative angiographic measurements were made before treatment, after laser angioplasty, after adjunctive balloon angioplasty and at 6-month angiographic follow-up in 168 patients with 179 treated lesions. Results. The immediate increase in lumen diameter (total acute gain 1.45 +/- 0.71 mm [mean +/- SD]) was due to the combination of laser treatment (0.79 +/- 0.61 mm) and subsequent adjunctive balloon angioplasty (0.66 +/- 0.55 mm). At follow up, the minimal lumen diameter had decreased (late loss 0.71 +/- 0.84 mm), yielding an overall restenosis rate of 50% (defined dichotomously by greater than or equal to 50% diameter stenosis). Multivariable regression analyses showed that restenosis was related to vessel diameter, as well as minimal lumen diameter, achieved immediately after the procedure. Conclusions. Although the restenosis rates for the small vessels typically treated with excimer laser angioplasty were high, the lowest restenosis rates were seen in large vessels with the largest postprocedural minimal lumen diameters. The goal of this procedure should be to safely achieve the largest lumen possible with the combination of laser treatment and adjunctive balloon dilation.