Transfemoral Aortic Valve Replacement Effective in High-risk Patients

　　导管设计的改进降低了不良事件发生率，包括神经系统和血管并发症。来自哥伦比亚大学医学中心内科教授、CRF创始人Martin B. Leon医生认为主动脉瓣狭窄的高危患者经股逆行经导管行主动脉瓣置换术是可行的，并且死亡率在可接受范围。

　　在一项综合分析了REVIVAL II (n = 55)、REVIVE II (n = 90), 和Canadian Special Access(n = 99)三项临床试验的结果发现1年的生存率与全部人群相似（73% ~ 74.7%，见下图）。

 
　　临床结果包括63例MACE：51例死亡（12%发生在术后30天），7例MI和14例卒中。神经系统和血管并发症仍较常见，需要以后研究加以改善，尽管高危患者的死亡率是可以接受的。目前各研究的应用的器械为RetroFlex THV Delivery System（Edwards Life Sciences）。

　　根据EuroSCORE，有25%的患者风险预测小于20%，有54%的患者Logistic EuroSCORE在20~40%之间。Leon认为EuroSCORE很难用做绝对风险预测积分，因为其不能包括全部变量。共有88%的患者成功进行了瓣膜置换，26置换失败，其中包括10例患者血管通路开通失败。

　　可行性研究

　　REVIVE II 和REVIVAL II是在欧洲和北美进行的相似的可行性研究。研究的主要终点为术后30天，3个月，6个月和12个月的死亡、MI、卒中和紧急心外科手术事件的发生率。

　　Canadian Special Access研究是在温哥华开展的一项姑息治疗研究，该研究的操作技术和随访协议与前两项研究相似。汇总资料显示患者的平均年龄为83.2岁，女性占47%。入选标准为严重主动脉瓣狭窄并且属外科手术高危患者。有34%的患者曾行外科手术，28%的患者有慢性阻塞性肺病。

　　Leon认为，此类患者的远期生存率受到并发疾病的影响，以后在这类患者中进行研究时应充分重视这一问题；导管设计的改进可减少并发症，特别是血管并发症，甚至于可能降低中风的发生率并提高远期的存活率。

　　（北京安贞医院　乔岩　阜外心血管病医院　高立建　编译）

Transfemoral Aortic Valve Replacement Effective in High-risk Patients

Improvements in catheter design could decrease rate of adverse events, including neurologic,vascular complications.

Retrograde transfemoral transcatheter aortic valve replacement can be performed with acceptable mortality in high-risk aortic stenosis patients, according to Martin B. Leon, MD, CRF founder and professor of medicine at Columbia University Medical Center.

In a pooled analysis of the REVIVAL II (n = 55), REVIVE II (n = 90), and Canadian Special Access (n = 99) clinical trials, freedom from death at 1 year was similar across the entire population (range, 73% to 74.7%, Figure).

Clinical outcomes included 63 major adverse cardiac events: 51 deaths (12% in the first 30 days), seven MIs, and 14 strokes. “Neurologic and vascular complications remain frequent,” Leon said. “These are things we should work on for the future.” The mortality rate in these high-risk patients, though, was acceptable, he noted. The device used in the study was the RetroFlex THV Delivery System (Edwards Life Sciences).

Using EuroSCORE, about onequarter of patients had a risk profile less than 20%, and 54% had a logistic EuroSCORE of 20% to 40%. Leon said EuroSCORE is difficult to use as an absolute risk profile score because it does not capture all the variables.

The researchers had 88% implant success and 26 unsuccessful deployments, including failed vascular access in 10 patients.

Feasibility studies

REVIVE II and REVIVAL II are similar feasibility studies in Europe and North America. The primary endpoints are death, MI, stroke or urgent cardiac surgery at 30 days, 3, 6 and 12 months.

Canadian Special Access is a compassionate-use study in Vancouver using a similar procedural technique and follow-up protocol to the other two studies.

Pooled data show the average patient age was 83.2 years; 47% were women. The patients were included if they had severe aortic stenosis and were at high risk for surgery. Thirtyfour percent of patients had undergone prior surgery, and 28% had chronic obstructive pulmonary disease.

“Long-term survival in this patient population is limited by their comorbidities,” Leon said. “[It should be] a core consideration as we plan clinical trials in these patients … and improvements in catheter design may decrease some of these complications, particularly the vascular complications and maybe even the strokes, and further improve survival.”