BACKGROUND: Although drug-eluting stents have proven to be highly effective in decreasing neointimal hyperplasia and its direct clinical consequence, restenosis, concerns regarding their long-term safety have led to the development of new technologies. The systemic use of antiproliferative drugs may resolve restenosis while minimizing the longterm safety issues inherent to synthetic polymers. Recently, a study investigating the intravenous administration of albumin-bound paclitaxel (ABI-007) showed that it produced a mild effect on the reduction of neointimal tissue formation. The present study was aimed at investigating, by means of serial angiography and intravascular ultrasound (IVUS), the efficacy of intracoronary ABI-007 administration in the suppression of neointimal hyperplasia after bare-metal stent implantation METHOD: From November 2006 and May 2007, patients with de novo coronary lesions < 18 mm were submitted to percutaneous coronary intervention using bare-metal stents, followed by a 70 mg/m² intracoronary injection of ABI-007. Angiography and IVUS assessment was planned for all of the patients immediately after the procedure and at the six-month follow-up. The primary end-point was late lumen loss (LL) and percent neointimal volume obstruction caused by neointimal hyperplasia (IVUS) at 6 months RESULTS: 11 patients were included, with mean age of 58.4 ± 7.3 years, 54% were female and 18.2% diabetics. Left anterior descending artery was the most frequent vessel treated (45.5%) and most of the lesions were type A/B1 (63.7%). ABI-007 administration was well tolerated by all patients. At the 6-month follow-up, LL was 0.84 ± 0.46 mm and three cases (27.3%) of binary restenosis were identified. IVUS percent volumetric obstruction was 38.4 ± 16.2%. No cases of significant vascular remodeling or late acquired stent malapposition were observed. After two years, there were no cases of major adverse cardiac events CONCLUSION: Although the intracoronary ABI-007 administration was well tolerated, with no adverse toxic events reported, this treatment modality demonstrated a low capacity of suppressing neointimal tissue formation after bare-metal stent implantation, with late loss and percent of volumetric obstruction percentages similar to those observed after bare-metal stent implantation alone.
Nanoparticles; Paclitaxel; Coronary restenosis; Stents
