RIBS-II研究4年结果显示: SES治疗支架内再狭窄安全有效

要点：
SES与球囊成形术相比，支架内再狭窄的临床事件率更低
SES早期靶血管血运重建的受益得以长期维持
SES的长期安全性必须进一步评估

根据发表在JACC 2008年11月11日一项研究的长期结果显示, 西罗莫司洗脱支架（SES）对于支架内再狭窄的治疗持续安全有效。与球囊成形术相比，置入SES后4年无事件生存率更高，可独立预测生存率。

RIBS-II研究（支架内再狭窄：球囊成形术与选择性西罗莫司洗脱支架比较），圣卡洛斯医院（马德里，西班牙）的Fernando Alfonso博士和他的同事随机入选了150例裸金属支架内再狭窄患者分别置入SES（76例）或者行球囊成形术（74例）。对所有150例患者进行了1年随访，145例(96.7%)患者临床随访超过3年(平均: 1,151 ± 262 天)。

通过对两组患者的长期随访，死亡和心肌梗塞的安全硬终点整体上是相同的。主要由靶血管血运重建(TVR)驱动的复合临床事件，在SES组的发生率更低。另外，置入SES组第一年（表1）早期TVR受益会维持到长期随访（表2）。

*n例患者的研究结果。没有计算百分比。4年无事件生存率，SES组为76%，球囊成形术组为65%(P = 0.019)。多元分析结果显示，球囊成形术是对主要不良事件长期风险的独立预测因素(HR 2.30; 95% CI, 1.21-4.40; P = 0.01).

ARC确定的1年后支架血栓的发生率”非常低”, 尽管SES组极晚期支架血栓很常见，但差别不显著（表3）。

在SES组有22例患者氯吡格雷治疗超过1年，16例患者超过2年，15例患者随访最后时仍在使用。任何时间或者第一年随访后的不良事件与患者使用氯吡格雷情况无关。作者推断出：“我们的研究采用了系统性、前瞻性、完整临床随访，为在挑战性情况下置入SES的长期安全性提供了重要保证。

“值得注意的是，1年后，临床TVR的需求非常低。这也就排除了因潜在SES引起的晚期追赶现象而使长期安全性降低的顾虑。”

临床最重要事情的长期结果

RIBS-II研究的补充研究，例如SISR研究结果发现，尽管SES支架血栓的绝对发生率(3.5%)有一点高，但SES置入3年后的有效性优于缓释（放射）治疗。

在一份警示说明中，研究人员提到一项观察研究（Sheiban等人），评估了临床随访2年的138例置入SES患者，支架内再狭窄的发生率。结果令人担忧，6个月、12个月和24个月的主要事件发生率分别为5.8%、14.3%和25%。他说：“因此，与相对简单的治疗策略如球囊成形术相比，评价支架内再狭窄患者置入SES的长期安全性及有效性，仍是临床实践中最重要的事。”

（source：www.tctmd.com）

（《医心评论》 陆卫 翻译 刘瑞琦 校对）

From JACC: RIBS-II: SES Safe, Effective for In-Stent Restenosis up to 4 Years

Key Points:
Fewer clinical events with SES vs. balloon angioplasty for in-stent restenosis

By Kiersten Feil
Long-term results show that sirolimus-eluting stents (SES) continue to be a safe and effective therapy for in-stent restenosis, according to a study published in the November 11, 2008, issue of the Journal of the American College of Cardiology. Compared to balloon angioplasty, SES implantation was associated with better event-free survival rates at 4 years and was an independent predictor of survival.

For the RIBS-II (Restenosis Intra-stent: Balloon angioplasty vs. elective sirolimus-eluting Stenting) trial, Fernando Alfonso, MD, of the Clinico San Carlos (Madrid, Spain), and colleagues randomized 150 patients with bare-metal in-stent restenosis to either SES implantation (n = 76) or balloon angioplasty (n = 74). One-year follow-up was obtained in all 150 patients. Clinical follow-up beyond 3 years (mean: 1,151 ± 262 days) was obtained in 145 patients (96.7%).

Overall, at long-term follow-up, the hard safety endpoints of death and myocardial infarction (MI) were equivalent for the 2 groups. The composite of any clinical events, driven mainly by target vessel revascularization (TVR), was lower in the SES arm. Plus, the early TVR benefit achieved with SES during the first year (table 1) was maintained at long-term follow-up (table 2).

Table 1. One-Year Clinical Events

Table 2. Four-Year Clinical Events

Abbreviation: MI, myocardial infarction.
*Results given in ‘n’ number of patients. Percentages not calculated.

At 4 years, event-free survival was 76% in the SES arm and 65% in the balloon angioplasty arm (P = 0.019). And on multivariate analysis, balloon angioplasty was an independent predictor of very long-term risk for any major adverse event (HR 2.30; 95% CI, 1.21-4.40; P = 0.01).

The incidence of ARC-defined stent thrombosis after 1 year was “very low,” and even though very late stent thrombosis was more frequent in the SES group, the difference was not significant (table 3).

Table 3. Stent Thromboses at Last Follow-up

Clopidogrel therapy was maintained for more than 1 year in 22 of the SES patients, more than 2 years in 16, and was still being used at last follow-up in 15 SES patients. Adverse events at any time or after the first year of follow-up were not related to clopidogrel status in any patients.