NEW APPROACH TO QUANTITATIVE ANGIOGRAPHIC ASSESSMENT AFTER STENT IMPLANTATION

The new generation quantitative angiographic systems apply the interpo lated technique to calculate the reference diameter at the site of the stenosis by integrating measurements of the segments proximal and dis tal to the stenosis, After stent implantation these measurements can b e misleading as the treated segment, which is frequently larger than t he adjacent not stented segments, is included in the measurements, The consequence is an overestimation of the reference diameter and the re sidual diameter stenosis. The present study was performed to compare t his conventional technique of measurement with a new method which excl udes the stented segment for the calculation of the reference diameter . Fifty-two lesions treated with poorly radiopaque stents (56% Palmaz- Schatz, 28% NIR, 10% Gianturco-Roubin, 6% Wallstent) expanded at high pressure(greater than or equal to 16 atm) were analyzed according to t he conventional and stent excluded method, After stent implantation th e reference diameter was 3.39 +/- 0.48 mm with conventional measuremen ts and 3.02 +/- 0.45 mm with the stent excluded method (P < 0.05). The corresponding % diameter stenosis was 13 +/- 9 for the conventional t echnique and 1 +/- 13 for the stent excluded analysis (P < 0.05), The new approach to quantitative coronary analysis after stenting provides higher accuracy in reference diameter calculations and allows a more appropriate matching of stented segments with adjacent normal segments . (C) 1997 Wiley-Liss, Inc.