Department of Cardiology, University of Bern, Switzerland.
Lancet. 2011 Dec 3;378(9807):1940-8. doi: 10.1016/S0140-6736(11)61672-3. Epub 2011 Nov 8.
The effectiveness of durable polymer drug-eluting stents comes at the expense of delayed arterial healing and subsequent late adverse events such as stent thrombosis (ST). We report the 4 year follow-up of an assessment of biodegradable polymer-based drug-eluting stents, which aim to improve safety by avoiding the persistent inflammatory stimulus of durable polymers.
We did a multicentre, assessor-masked, non-inferiority trial. Between Nov 27, 2006, and May 18, 2007, patients aged 18 years or older with coronary artery disease were randomly allocated with a computer-generated sequence to receive either biodegradable polymer biolimus-eluting stents (BES) or durable polymer sirolimus-eluting stents (SES; 1:1 ratio). The primary endpoint was a composite of cardiac death, myocardial infarction, or clinically-indicated target vessel revascularisation (TVR); patients were followed-up for 4 years. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00389220.
1707 patients with 2472 lesions were randomly allocated to receive either biodegradable polymer BES (857 patients, 1257 lesions) or durable polymer SES (850 patients, 1215 lesions). At 4 years, biodegradable polymer BES were non-inferior to durable polymer SES for the primary endpoint: 160 (18·7%) patients versus 192 (22·6%) patients (rate ratios [RR] 0·81, 95% CI 0·66-1·00, p for non-inferiority <0·0001, p for superiority=0·050). The RR of definite ST was 0·62 (0·35-1·08, p=0·09), which was largely attributable to a lower risk of very late definite ST between years 1 and 4 in the BES group than in the SES group (RR 0·20, 95% CI 0·06-0·67, p=0·004). Conversely, the RR of definite ST during the first year was 0·99 (0·51-1·95; p=0·98) and the test for interaction between RR of definite ST and time was positive (p(interaction)=0·017). We recorded an interaction with time for events associated with ST but not for other events. For primary endpoint events associated with ST, the RR was 0·86 (0·41-1·80) during the first year and 0·17 (0·04-0·78) during subsequent years (p(interaction)=0·049).
Biodegradable polymer BES are non-inferior to durable polymer SES and, by reducing the risk of cardiac events associated with very late ST, might improve long-term clinical outcomes for up to 4 years compared with durable polymer SES.
Biosensors Europe SA, Switzerland.
耐用聚合物药物洗脱支架的有效性是以延迟动脉愈合和随后的晚期不良事件（如支架血栓形成[ST]）为代价的。我们报告了生物可降解聚合物药物洗脱支架的 4 年随访结果，该支架旨在通过避免耐用聚合物的持续炎症刺激来提高安全性。
我们进行了一项多中心、评估者盲法、非劣效性试验。在 2006 年 11 月 27 日至 2007 年 5 月 18 日期间，年龄在 18 岁或以上的患有冠状动脉疾病的患者被随机分配到计算机生成的序列中，以接受生物可降解聚合物的生物素-雷帕霉素洗脱支架（BES）或耐用聚合物的西罗莫司洗脱支架（SES）（1:1 比例）。主要终点是心脏死亡、心肌梗死或临床指征明确的靶血管血运重建（TVR）的复合事件；患者随访 4 年。分析采用意向治疗。这项试验在 ClinicalTrials.gov 注册，编号为 NCT00389220。
共有 1707 名患者，2472 处病变，随机分配接受生物可降解聚合物 BES（857 名患者，1257 处病变）或耐用聚合物 SES（850 名患者，1215 处病变）。4 年后，生物可降解聚合物 BES 在主要终点上不劣于耐用聚合物 SES：160 名（18.7%）患者与 192 名（22.6%）患者（比值比[RR]0.81，95%CI0.66-1.00，p<0.0001，p 优于非劣效性=0.050）。明确 ST 的 RR 为 0.62（0.35-1.08，p=0.09），这主要归因于 BES 组在 1 年至 4 年之间非常晚期明确 ST 的风险较低，而 SES 组的风险较高（RR 0.20，95%CI0.06-0.67，p=0.004）。相反，第 1 年明确 ST 的 RR 为 0.99（0.51-1.95；p=0.98），且明确 ST 的 RR 与时间之间的交互检验为阳性（p（交互）=0.017）。我们记录到与 ST 相关的事件与时间之间存在交互作用，但与其他事件无关。对于与 ST 相关的主要终点事件，RR 在第 1 年为 0.86（0.41-1.80），在随后的年份为 0.17（0.04-0.78）（p（交互）=0.049）。
生物可降解聚合物 BES 不劣于耐用聚合物 SES，通过降低与迟发性 ST 相关的心脏事件风险，与耐用聚合物 SES 相比，可能在长达 4 年的时间内改善长期临床结局。
瑞士 Biosensors Europe SA。
