Division of Cardiology, University of Texas Southwestern Medical Center, 2001 Inwood Road Suite WC05.852, Dallas, TX, 75390-9254, USA.
Curr Atheroscler Rep. 2019 Nov 25;21(12):54. doi: 10.1007/s11883-019-0816-4.
The purpose of this review is to explore the evolution of the coronary stent, from the advent of bare-metal stents, to the newest adopted technology of bioresorbable vascular scaffolds (BVS) used in bioresorbable stents. To date, there have been conflicting data regarding the safety and efficacy of BVS stents, especially when compared to current-generation drug-eluting stents (DES). This review will cover the data that exist regarding current BVS stents, as well as the active clinical trials for future iterations of BVS.
The ABSORB BVS, the most widely circulated stent of its class, was promised to decrease rates of stent thrombosis and target vessel revascularization. Several randomized control trials, however, found the opposite to be true, with the ABSORB BVS demonstrating higher rates of thrombosis, target vessel revascularization, and even target lesion myocardial infarctions when compared to current-generation DES. These data caused the product to be pulled from all markets, leaving the field with uncertainty as to the role of BVS in coronary interventions. Coronary stents have evolved significantly from 1977, when they were first introduced. The original bare-metal stent was later fitted with a drug-eluting polymer, to prevent restenosis and thrombosis over time. Subsequent iterations of the stent attempted to further mitigate that risk by replacing the durable polymer to one that is bioresorbable. The final step in this progression was to create a stent that was fully bioresorbable, which Abbott did with the creation of their ABSORB BVS stent. The product, however, was found to perform poorly when compared to current-generation drug-eluting stents, with several trials showing high rates of stent thrombosis (ST), late stent thrombosis (LST), target-lesion myocardial infarction, and target vessel revascularization. Observational studies of BVS stents have proposed several mechanisms for their thrombogenicity, including higher stent-strut profiles leading to turbulent flow, low radial strength leading to strut disruption, and a higher propensity for neoatherosclerosis. Given the failure of the first-generation BVS stent, but the lingering desire for fully bioresorbable scaffolds, various manufacturers have proposed their solutions with new stents. Until data from their clinical trials emerge, it remains unclear whether fully bioresorbable stents will play any role in coronary interventions.
本文旨在探讨冠状动脉支架的发展历程，从金属裸支架的问世，到最新采用的生物可吸收血管支架（BVS）技术。迄今为止，关于 BVS 支架的安全性和有效性仍存在争议，尤其是与目前的药物洗脱支架（DES）相比。本综述将涵盖目前关于 BVS 支架的现有数据，以及未来 BVS 迭代的临床试验。
ABSORB BVS 是该类支架中应用最广泛的支架，其设计目的是降低支架内血栓形成和靶血管血运重建的发生率。然而，几项随机对照试验的结果却恰恰相反，ABSORB BVS 支架血栓形成、靶血管血运重建甚至靶病变心肌梗死的发生率均高于目前的 DES。这些数据导致该产品从所有市场撤出，使人们对 BVS 在冠状动脉介入治疗中的作用产生了不确定性。自 1977 年首次问世以来，冠状动脉支架已经有了显著的发展。最初的金属裸支架后来被装上了一种药物洗脱聚合物，以防止随着时间的推移发生再狭窄和血栓形成。支架的后续迭代试图通过用生物可吸收聚合物取代耐用聚合物来进一步降低这种风险。这一发展过程的最后一步是制造一种完全可生物吸收的支架，雅培公司通过制造他们的 ABSORB BVS 支架实现了这一目标。然而，与目前的药物洗脱支架相比，该产品的性能较差，多项试验显示支架内血栓形成（ST）、晚期支架内血栓形成（LST）、靶病变心肌梗死和靶血管血运重建的发生率较高。对 BVS 支架的观察性研究提出了其血栓形成的几种机制，包括较高的支架支柱轮廓导致湍流、较低的径向强度导致支柱断裂，以及更高的新动脉粥样硬化倾向。鉴于第一代 BVS 支架的失败，但人们对完全可生物吸收支架的渴望依然存在，各种制造商已经提出了他们的解决方案，使用新的支架。在其临床试验数据出现之前，完全可生物吸收支架是否会在冠状动脉介入治疗中发挥作用仍不清楚。
