QUANTITATIVE ASSESSMENT OF PERIPHERAL AND CORONARY-ARTERY LESIONS BEFORE AND AFTER BALLOON ANGIOPLASTY - A COMPARISON OF INTRAVASCULAR ULTRASOUND AND ANGIOGRAPHY

Intravascular ultrasound and conventional angiography were used to det ermine the degree of stenosis before and after angioplasty in 25 conse cutive patients with peripheral arterial occlusive disease and 15 sele cted patients with coronary artery disease. Angiographic determination s of the luminal area and percent stenosis were made with the help of an automatic detection system, and the same parameters were evaluated planimetrically in the ultrasound studies. Following angioplasty of pe ripheral lesions, angiography demonstrated a significantly greater inc rease in mean luminal area (10.8 +/- 7.8 mm2 vs 5.8 +/- 4.0 mm2; P < 0 .05) and a greater reduction in degree of stenosis (26% +/- 16% vs 14% +/- 11%; P < 0.05) than did the ultrasonic investigation. There was a significant but moderate correlation between values for the luminal a rea determined by angiography and ultrasound before angioplasty (r = 0 .75; SEE = 4.8 mm2) and in normal proximal segments of coronary arteri es (r = 0.79; SEE 4.1 MM2) . Following angioplasty there was no signif icant correlation between angiographic findings and those determined b y intravascular ultrasound in peripheral or coronary lesions. These re sults suggest that angiography and intravascular ultrasound are fundam entally different imaging and analysis techniques. Following angioplas ty, conventional angiography rarely demonstrated dissection or intralu minal filling defects, while intravascular ultrasound detected plaque rupture and the presence of intraluminal atheroma in almost all cases. Quantitative determinations of luminal area and degree of stenosis re ly on indirect measures with conventional angiography, while these par ameters are determined directly by intravascular ultrasound. Additiona l studies and clinical experience should demonstrate whether intravasc ular ultrasound will play a significant role in the planning and manag ement of vascular interventions.