[TCT2007]SPIRIT III试验1年结果公布：Xience V支架与TAXUS支架没有差别

SPIRIT III at 1 Year: Xience V Noninferior to Taxus                              

　　患者置入第二代DES－Xience V支架较少的围手术期心肌梗死和较低6到12个月的靶病变重建率。

　　SPIRIT III是一项多中心随机对照试验，Xience V支架（everolimus-eluting stent）和TAXUS支架（paclitaxel-eluting stent）相比，在靶血管失败（TVF）方面间无差别；支架置入后6个月和12个月临床随访靶病变重建率（TLR）前者明显低于后者。
 
　　CRF主席Gregg W. Stone医生报告SPIRIT III试验1年结果显示：Xience V支架组在死亡率、心肌梗死、和支架内血栓发生率方面与TAXUS支架组没有差别。他说支架内血栓这一发生率较低的事件在两种支架间是否存在差别还需要大规模的临床试验来验证，尤其在受关注的亚组人群如糖尿病患者。
 
　　节段内晚期丢失

　　Stone医生解释SPIRIT III的主要终点8个月节段内晚期管腔丢失（LL），TAXUS支架LL为0.28mm，节段内LL降低50%，而Xience V支架LL为0.14mm。97.4％的入选患者完成了12个月临床随访，包括Xience V支架组655例患者。但Xience V支架组TVF（定义为心源性死亡、心肌梗死和缺血导致的靶血管重建）无明显的下降趋势（XIENCE 8.3% vs TAXUS 10.8%，P = 0.18）。与TVF相比，研究终点MACE（包括心源性死亡、心肌梗死和缺血导致的TLR）是针对支架本身更合适的指标，XIENCE支架的MACE发生率较TAXUS支架组减少43％（XIENCE 5.8% vs TAXUS 9.9%）

　　支架置入1年TLR两组间没有差别（TAXUS 5.6% vs XIENCE 3.3%，p＝0.09），9个月支架内血栓发生率两组间略有差别但未达到统计学差别，1年时支架内血栓发生率没有差别。

SPIRIT III试验－美国65个中心参加

　　美国有65个中心参加SPIRIT III试验，共入选了1002例患者，入选标准中，血管直径2.5-3.75mm，病变长度不超过28mm，最多2处病变，入选的患者按照2:1的比例随机分到Xience V支架组或TAXUS支架组。

　　两组入选人群的基线资料相匹配，虽然TAXUS支架组有更多的不稳定心绞痛患者。两组中每位患者的病变部位、数量相似，在支架置入后6个月、9个月以及12个月随访患者对抗血小板药物顺应性良好。
 
　　需要更接近于临床实践的资料

　　Stephen G. Ellis医生在对Stone医生报告的SPIRIT III试验讨论时给予高度评价。Xience V支架置入1年的安全性资料与其他DES支架间没有差别。但需要提供更多的Xience V在日常临床实践中应用效果的资料，包括糖尿病患者、真正的小血管病变（RVD<2.5mm）或长病变（病变长度超过20mm）。

　　Ellis说：“即将开始的SPIRIT IV试验将会很好的解决这一问题，SPIRIT IV 将入选3690例患者，按照2:1比例随机分到Xience V组或TAXUS支架组，采用非劣效性和优效性检验方法使其有较高的检验效能。”

　　（阜外心血管病医院　高立建　陈俊　编译）

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SPIRIT III at 1 Year: Xience V Noninferior to Taxus

Patients with the second-generation drug-eluting stent had fewer periprocedural MIs and fewer TLR procedures, at 6 to 12 months.

With 1-year follow-up in the multicenter randomized SPIRIT III trial, the Xience V everolimus-eluting stent demonstrated noinferior rates of target vessel failure compared with the Taxus paclitaxel-eluting stent, and patients with the Xience V stent　had fewer TLR procedures than those with　the Taxus stent at 6 to 12 months.

Gregg W. Stone, MD, who presented　the 1-year results of SPIRIT III,said the rates of death, MI, and stent　thrombosis in the trial were not significantly different between the Xience V(Abbott Laboratories) and Taxus (Boston Scientific) stents.

Larger studies will be required to determine whether there are significant differences between the two devices in low-frequency safety events and in certain subgroups of interest, such as diabetic patients, said Stone, chairman of the Cardiovascular Research Foundation.

In-segment late loss

Stone noted that one previously announced primary endpoint of the SPIRIT III trial, in-segment late loss (LL) at 8 months, was relevant to the current presentation. He said Xience V reduced in-segment LL by 50%, from 0.28 mm with Taxus to 0.14 mm.

At 12 months, investigators achieved 97.4% patient follow-up, including 655 patients with the Xience V DES.

There was a nonsignificant trend toward reduction in TVF with the Xience V stent (8.3% with Xience vs. 10.8% with Taxus, P = .18). TVF as defined in the study included cardiac death, MI, and ischemia-driven TVR.

Stone noted that the endpoint of major adverse cardiac events (MACE) – including cardiac death, MI, and ischemia-driven TLR–is"more specific to the stent itself,"as opposed to TVF. For this endpoint, the difference of 43% between the devices (9.9% with Taxus vs. 5.8% with Xience V) was statistically significant, favoring Xience V (Figure).

A nonsignificant trend favoring the Xience V DES was seen in ischemiadriven TLR at 1 year (5.6% with Taxus vs. 3.3% with Xience, P = .09). There was a nonsignificant trend favoring Taxus in stent thrombosis through 9 months, but the difference disappeared by 1 year.

65 U.S. sites in trial

The SPIRIT III trial included 1,002 patients at 65 U.S. sites with a maximum of 2 lesions of 28 mm or less in length and 2.5 to 3.75 mm in diameter, each in a different epicardial vessel. Patients were randomized 2:1 to receive Xience V or Taxus.

Baseline demographics were well-matched between the two groups, Stone said, although there was a significantly greater incidence of unstable angina in the Taxus group. Lesion location and number of lesions per patient were similar between groups. Compliance with antiplatelet regimens was good in both groups at 6, 9, and 12 months.

Everyday patient data needed

In a critical appraisal of the SPIRIT III trial following Stone’s presentation, Stephen G. Ellis, MD, of the Cleveland Clinic, said that the 1-year safety data for Xience V are comparable with those for other DES.

He said more data will be needed about the performance of the stent in"everyday"patients, including those with diabetes and those with lesions that are"truly small"(reference vessel diameter less than 2.5 mm) or long (greater than 20 mm lesion length).

More data on these types of lesions will be forthcoming from the SPIRIT IV trial, which will include 3,690 patients randomized 2:1 to receive either the Xience V or Taxus DES and will be powered for sequential noninferiority and superiority testing, Ellis said.