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.