Long-term evaluation of paclitaxel-coated stents for treatment of native coronary lesions. First results of both the clinical and angiographic 18 month follow-up of TAXUS I.

The development of restenoses due to tissue proliferation within the stented segment is a major limitation of conventional stent implantations. Recently published studies have shown that drug-eluting stents effectively decrease the incidence of stent restenosis at 6 month follow-up as compared to bare metal stents. However, a persistent efficacy of this stent design beyond the 6 month period still needs to be proven. Therefore, in this study, we are demonstrating the first 18 month follow-up results of a Paclitaxel-coated coronary stent, based on the patient population of the TAXUS I study, a multicenter randomized study to evaluate both safety and efficacy of the Paclitaxel-coated NIRx stent as compared to an uncoated, bare metal stent. In this study we evaluated the long-term outcome of NIRx patients of our center, in which 20 out of 31 patients of the TAXUS I study with NIRx stent implantation have been enrolled. A clinical follow-up was available in 20 out of 20 patients (100%) 535 +/- 82 days post stent implantation (17.8 months). An angiographic follow-up was available in 14 out of 20 patients (70%) 580 +/- 77 days post stent implantation (19.1 months). The MACE rate at 18 month follow-up was 0.0%. There was no stent restenosis in the study group up to 18 month post drug-eluting stent implantation. There was one non-clinically driven target vessel revascularization due to a stent edge lumen renarrowing, which was subsequently calculated as a 43% diameter stenosis. Accordingly, this event was not regarded as MACE. The IVUS analysis of the study population has shown a decrease of the mean minimum lumen area from 8.45 mm(2) postinterventional to 6.87 mm(2) at 6 month follow-up with a relative mean maximum plaque area of 16%. At 18 month follow-up, there were no additional significant changes with a mean minimum lumen area of 7.16 mm(2) and a relative mean maximum plaque area of 13.4%. The reported results of the 18 month follow-up of TAXUS I are the first experiences demonstrating a persistent benefit of the Paclitaxel-coated NIRx stent. Therefore, this stent design seems to be safe and effective, even in long-term follow-up.

Drug eluting stents: initial experiences.

Local delivery of immunosuppressive or antiproliferative agents using a drug-eluting stent is a new technology meant to inhibit in-stent restenosis providing both a biological and mechanical solution and has recently emerged as a very promising approach. Up to now several agents have been in use: Paclitaxel, Rapamycin, Actinomycin D or Tacrolimus. Evaluating these drugs regarding their release kinetics, effective dosage, safety in clinical practice and benefit, several studies have been published or are still ongoing: SCORE (Paclitaxel-derivative), TAXUS I, II, III, IV (Paclitaxel), ELUTE, ASPECT (Paclitaxel), RAVEL, SIRIUS (Sirolimus), ACTION (Actinomycin), EVIDENT, PRESENT (Tacrolimus). Paclitaxel was the first stent-based antiproliferative agent under clinical investigation providing profound inhibition of neointimal thickening, depending on delivery duration and drug dosage. The randomized multicenter SCORE trail (Quanam stent, Paclitaxel coated) enrolled 266 patients at 17 sites. At 6 month follow-up, a drop of 83% in stent restenosis using the drug-eluting stent could be achieved (6.4% drug-eluting stent vs. 36.9% control group) attributable to a remarkable decrease in intimal proliferation. Unfortunately, due to both frequent stent thrombosis and side-branch occlusions the reported 30-day MACE rate was 10.2%. The randomized TAXUS I safety trail (NIRx, Paclitaxel coated) also demonstrated beneficial reduction of restenotic lesions at 6-month FU (0% vs. 11%) but, this time, associated with the absence of thrombotic events presumably due to the lower drug dosage. The ongoing TAXUS II, III and IV trails are aimed at providing additional insight regarding the efficacy of the TAXUS Paclitaxel-eluting stent. Both the RAVEL and the SIRIUS trial have been conducted to evaluate a Sirolimus-coated stent (Bx VELOCITY stent). From the results available, the beneficial findings regarding reduction of renarrowing using a drug-eluting stent have been confirmed without any adverse effects. Although parameters like drug toxicity, optimal drug dosage or delayed endothelial healing need to be further evaluated, summarizing the today's clinical experience the strategy of drug-coated stents promises a striking benefit in interventional treatment of coronary lesions.