COMPARISON OF IMMEDIATE AND INTERMEDIATE-TERM RESULTS OF INTRAVASCULAR ULTRASOUND VERSUS ANGIOGRAPHY-GUIDED PALMAZ-SCHATZ STENT IMPLANTATION IN MATCHED LESIONS

Background Intravascular ultrasound (IVUS) provides more precise infor mation than angiography about vascular dimensions. This information is used by some centers tc, optimize intracoronary stent implantation. T here are no direct comparisons of the effects on restenosis of optimal IVUS-guided versus angiography-directed high-pressure stenting. Metho ds and Results Lesions of patients who had a 6-month angiographic foll ow-up study were eligible for matching. From 445 consecutive lesions t reated by Palmaz-Schatz (P-S) stenting guided by IVUS (IVUS group) in Milan, 173 lesions were individually matched with 173 of 476 consecuti ve lesions treated by P-S stenting directed by angiography (Angio grou p) in Hamburg. Lesions were selected by a computerized program accordi ng to baseline clinical, angiographic, and procedural variables. Immed iate and 6-month angiographic results were retrospectively compared, d istinguishing an ''early phase'' from a ''late phase.'' This distincti on was based on the more aggressive dilation strategy with larger ball oons and more demanding a IVUS criteria for optimal stent expansion us ed in Milan in the early phase. In both phases, a larger minimum lumen diameter (MLD) immediately after stenting and after 6 months was achi eved in the IVUS group than in the Angio group. In the early phase, th e dichotomous restenosis rate was lower in the IVUS group than in the Angio group (9.2% versus 22.3%; P=.04). In the late phase, there was n o difference in restenosis between the groups (22.7% versus 23.7%; P=1 .0). Conclusions In matched lesions treated with high-pressure stentin g, IVUS guidance achieved a larger MLD than angiographic guidance. How ever, in the IVUS group, the restenosis rate was lower only in the ear ly phase, when balloons larger than currently used were selected to ma ximize the stent lumen area.