Are Biodegradable Third Generation Drug Eluting Stents the Answer to Instent Restenosis.

The third generation biodegradable Drug Eluting Stent (DES) are being evaluated and being introduced in clinical practice. They have been DESigned to overcome limitations associated with durable polymer and a persistent metallic stent scaffold which could be related to late target lesion revascularization (TLR) and very late stent thrombosis (VLST). Although a recent pooled data analysis found that biodegradable polymer stents were superior for TLR and VLST compared with first generation Sirolimus Eluting Stent (SES), superiority has not been demonstrated against second generation Everolimus eluting stents (EES) and is yet to be conclusively proven in randomized trials. This paper reviews the key features, recent trial data, and future directions of the third generation of DES technology including stents with fully biodegradable scaffolds, stents with biodegradable polymer, and polymer free stents.

Tratamento de reestenose intrastent com o novo stent farmacológico firebird TM, limerador de sirolimus - Resultados angiográficos e ultrassonográficos de um ano de evolução / Treatment of in-stent restenosis with the new firebird TM sirolimus eluting stent - One year angiographic and intravascular ultrasound follow-up results

Introdução: A reestenose intrastent (RIS), resultante da excessiva resposta reparadora neointimal após o implante da prótese, é uma das principais limitações da intervenção coronária percutânea. A despeito da eficácia dos stents farmacológicos (SF) de primeira geração no tratamento da RIS, questões relacionadas à segurança e ao perfil de flexibilidade/navegabilidade dessas próteses estimularam o desenvolvimento de novas gerações de SF. O novo SF Firebird TM (Microport Co. Ltd., Xangai, China) combina uma plataforma de aço inoxidável (316 L) de hastes finas (0,0040 polegada), um potente agente antiproliferativo (sirolimus, na dose de 9 ug/mm2) e um revestimento que inclui três camadas de polímero durável, que controla a liberação do fármaco. Apesar de ser um dos SF mais utilizados na China, pouco se conhece sobre seu desempenho, sobretudo em subgrupos de maior complexidade. Método: Entre fevereiro e dezembro de 2009, pacientes portadores de lesão reestenótica única, de stents não-farmacológicos, foram submetidos a intervenão coronária percutânea com implante de stent Firebird TM. Avaliação com angiografia ultrassom intracoronário (USIC) foi programada para todos os pacientes...

BACKGROUND: In-stent restenosis (ISR), resulting from excessive neointimal hyperplasia, is a major limitation of percutaneous coronary intervention. Despite the efficacy of first generation drug-eluting stents (DES) in the treatment of ISR, issues related to the safety and flexibility/navigability profile have encouraged the development of new generations of DES. The new FirebirdTM DES (Microport Co. Ltd., Shanghai, China) combines a stainless steel platform (L316) of fine struts (0,0040'), a powerful anti-proliferative agent (sirolimus, at a dose of 9 µg/mm²) and a coating that includes three layers of a durable polymer, which controls drug release. Though it is a most used DES in China, little is known about its performance, particularly in subgroups of greater complexity. METHOD: Between February and December 2009, patients with single bare metal stent restenotic lesions, were submitted to percutaneous coronary intervention with FirebirdTM stent implantation. Angiography and intravascular ultrasound (IVUS) were scheduled for all patients at 12 months of follow-up. The primary end-point was late loss and the percentage of in-stent volumetric obstruction at 12 months. RESULTS: Twenty-five patients with mean age of 56.8 ± 7.7 years were included, of which 80% were males and 40% diabetics. The anterior descending artery was the most frequently treated vessel (44%) and most lesions had a diffuse/proliferative pattern (64%). At 12 months, late luminal loss was 0.3 ± 0.24 mm, and no case of binary restenosis was identified. IVUS percent volumetric obstruction was 2.6 ± 1.9%. CONCLUSION: In this single center study, the new FirebirdTM DES showed favorable angiographic and IVUS results for the treatment of bare metal ISR at the one year follow-up.

Newer stents: looking at the horizon.

More challenging and complex lesions are being treated with drug:eluting stents. This review examines advances in some of the commercially available stents together with important new stents under development. These include stents with novel platforms for drug elution, biodegradable, and bioabsorbable polymer/stents and stents dedicated to specific lesions. It also discusses novel pharmacological agents aimed at targeting inflammation and restenosis together with bio-engineered stents and combination drug therapies.