MULTIVARIATE PREDICTORS OF INTRAVASCULAR ULTRASOUND END-POINTS AFTER DIRECTIONAL CORONARY ATHERECTOMY

Objectives. This study attempted to identify the clinical, angiographi c, procedural and intravascular ultrasound predictors of directional a therectomy results assessed by intravascular ultrasound. Background. S everal angiographic and intravascular ultrasound variables have been a ssociated with the outcome of directional coronary atherectomy. No stu dy has incorporated both modalities into a predictive model. Methods. One hundred seventy patients were analyzed using preintervention and p ostintervention intravascular ultrasound and quantitative angiography. Clinical and procedural variables were collected by independent chart review. Quantitative and qualitative angiographic analysis was perfor med by a core laboratory in blinded manner. Intravascular ultrasound w as performed using a transducer tipped catheter. rotating within a sta tionary imaging sheath, and withdrawn automatically at 0.5 mm/s. Clini cal, procedural, angiographic and ultrasound variables were tested in a multivariate linear regression model. Dependent ultrasound variables included postatherectomy lumen cross-sectional area and percent cross -sectional narrowing (plaque plus media/external elastic membrane cros s-sectional area) and, in a subgroup of 47 patients studied using volu metric analysis, percent plaque volume removal. Results. By multivaria te stepwise linear regression analysis. predictors of residual lumen c ross-sectional area (correcting for reference lumen area) included are of calcium and preatherectomy plaque plus media cross-sectional area; predictors of residual cross-sectional narrowing were are of calcium, preatherectomy plaque plus media cross-sectional area and lesion leng th; and predictors of percent plaque volume removal were are of calciu m and atherectomy device size. Conclusions. The preintervention lesion are of calcium measured by intravascular ultrasound is the most consi stent predictor of the effectiveness and results of directional corona ry atherectomy.