Impact of Drug-Eluting Stents on Distal Vessels

Background— Previous studies have not addressed vessel response >5 mm distal to the stent edge. Therefore, we investigated the impact of paclitaxel-eluting stents (PES) versus bare metal stents (BMS) on distal vessels in the serial intravascular ultrasound substudies of TAXUS IV, V, and VI. Methods and Results— TAXUS IV, V, and VI were double-blind, randomized, multicenter, controlled trials comparing PES with BMS. In their intravascular ultrasound substudies, 103 patients (54 BMS, 49 PES) had intravascular ultrasound data ≥10 mm distal to the stent both postprocedure and at 9 months follow-up. Baseline characteristics were similar between the 2 groups. Multilevel modeling was used to account for the variation between patients and within patients among distal segments. Effect of stent type, time, and their interaction was tested using a mixed effect model controlling for distal segments. Postprocedure lumen and vessel were not significantly different between PES versus BMS; however, lumen (P=0.006) and vessel (P=0.0001) were significantly reduced for BMS at 9-month follow-up but not for PES. Conversely, there was a significant plaque increase from postprocedure to 9-month follow-up for PES (P=0.0008) but not for BMS. These vessel responses were statistically consistent among 0- to 5-mm versus 5- to 10-mm versus 10- to 15-mm segments distal to the stent in both groups. Conclusions— PES use was associated with plaque increase from baseline to 9-month follow-up >5 mm distal to the stent along with positive remodeling, whereas BMS use was associated with negative remodeling and no plaque increase. These vessel responses were consistent in 5-mm long subsegments: 0 to 5 mm versus 5 to 10 mm versus 10 to 15 mm distal to the stent. Clinical Trial Registration— URL: http://www.clinicaltrial.gov. Unique identifiers: TAXUS IV—NCT00292474; TAXUS V—NCT00301522; TAXUS VI—NCT00297804.