Effect of Stent Thrombosis on the Risk-Benefit Balance of Drug-Eluting Stents and Bare Metal Stents

Introduction and objectivesTo determine the difference in the risk of stent thrombosis between drugeluting stents (DES) and bare-metal stents (BMS) and to assess the clinical implications.MethodsA retrospective analysis of two cohorts of patients treated at our center with either ≥1 paclitaxeleluting stents (PES) (n=430) or ≥1 BMSs (n=1230) during 2003-2004 was carried out using propensity score methods to compare the adjusted risks of stent thrombosis, instent restenosis, cardiovascular death, acute myocardial infarction (AMI), and target-lesion revascularization with the two stent types.ResultsAfter a median follow-up of 46 months, there was a higher risk of stent thrombosis in PESs (hazard ratio [HR]=3; 95% confidence interval [CI], 1.2-7.1] though the risk of in-stent restenosis was lower (HR=0.3; 95% CI, 0.2- 0.7]. There was no difference in the risk of cardiovascular death, AMI or target-lesion revascularization. With PESs, the risks of target-lesion revascularization (HR=0.33; 95% CI, 0.2-0.7) and in-stent restenosis (HR=0.32; 95% CI, 0.2-0.7) were reduced during the first year of follow-up. After this time, the risks of target-lesion revascularization (HR=1.8; 95% CI, 1-3.2) and very late stent thrombosis (HR=12.8; 95% CI, 3-55.1) both increased.ConclusionsOur findings indicate that the balance of risks and benefits of PESs compared with BMSs is different in the early and late periods after stent implantation. The greatly increased risk of very late stent thrombosis in PESs could cancel out the clinical benefits associated with the reduction in in-stent restenosis observed in PESs relative to BMSs.

Introducción y objetivosEvaluar el riesgo de trombosis del stent (TS) de los stents liberadores de fármaco (SLF) frente a los stents convencionales (SC) y sus consecuencias clínicas.MétodosAnálisis retrospectivo de dos cohortes de pacientes tratados con al menos un stent liberador de paclitaxel (SLP) (n = 430) o uno o más SC (n = 1.268) en 2003-2004 en nuestro centro mediante métodos de score de propensión para comparar el riesgo ajustado de TS, reestenosis del stent (RIS), muerte cardiovascular, infarto de miocardio (IAM) y revascularización de la lesión tratada (RLT) entre ambos dispositivos.ResultadosTras una mediana de seguimiento de 46 meses, los SLP presentaron mayor riesgo de TS (hazard ratio [HR] = 3; intervalo de confianza [IC] del 95%, 1,2-7,1), si bien redujeron el riesgo de RIS (HR = 0,3; IC del 95%, 0,2-0,7). No hubo diferencias en cuanto a muerte cardiovascular, IAM o RLT. Los SLP disminuyeron el riesgo de RLT (HR = 0,33; IC del 95%, 0,2-0,7) y RIS (HR = 0,32; IC del 95%, 0,2-0,7) durante el primer año de seguimiento. Tras este límite, presentaron mayor riesgo de RLT (HR = 1,8; IC del 95%, 1-3,2) y de TS muy tardía (HR = 12,8; IC del 95%, 3-55,1).ConclusionesNuestros hallazgos confirman que hay una relación riesgo-beneficio precoz y tardía diferente entre el implante de un SLP y el de un SC. El exceso de riesgo de TS muy tardía puede limitar los beneficios clínicos de los SLP frente a los SC, relacionados con la disminución de la RIS.