得克萨斯州达拉斯的Todd M. Dewey医生在2008年7月发表在《胸外科年鉴》上的文章中对在REVIVAL II可行性研究中获得的经心尖主动脉瓣置换术美国经验进行了讨论。除了对器械进行安全有效性评价外，可行性研究还必须承担着对手术过程进行优化提高的作用。

Dewey医生说：“我们早就知道患者的选择是有限的（根据目前的风险评估工具）。”这些预测因子包括肺疾病、肺气肿等。他说：“研究纳入的患者对于进行心尖主动脉瓣置换术来说风险太高。而在研究开始时我们错误的认为这一手术可以适合任何患者。后来我们很快发现还是有很多患者病情太重了。”他认为应对入选标准进行修改。

公开：

• Webb医生报告是Edwards Lifesciences公司的顾问。
• Walther报告没有任何相关利益冲突。
• Dewey医生是Edwards Lifesciences公司的顾问。

（来源：www.tctmd.com）

Valvular Heart Disease Summit: Experience Impacts Outcomes

Key Points:

• Feasibility studies in U.S. and Europe indicate percutaneous approaches improve with more operator experience.

By TCT Daily Staff

Early studies of transcatheter aortic valve replacement have demonstrated that the technique is becoming safer and more effective as clinicians learn from initial experiences, according to data from three trials predominantly using the Edwards Sapien THV.

John Webb, MD, of St. Paul’s Hospital, Vancouver, Canada, presented findings on 172 patients from the Vancouver TAVR study. In those who underwent transarterial replacement (n=114), procedural success grew from 81.6% in the first tertile to 97.4% in both the second and third tertiles of patients treated.

Similarly, 30-day mortality rates were 13.2% in the first tertile, dropping to 10.5% in the second and 0% in the third tertile.

Procedural success was higher in transapical procedures (n=58): 96.6% for the first half treated and 100% for the latter half. In the same population, 30-day mortality dropped from 24.1% to 13.8% over time.

Webb noted a "steep learning curve" in understanding valve positioning and femoral access, major sources of morbidity, and mortality early in the series.

European TRAVERSE

The TRAVERSE feasibility study, presented by Thomas Walther, MD, of the University of Leipzig, Germany, assessed the European experience with transapical aortic valve replacement from December 2004 to April 2008 (see Table).

The main perioperative complications were apical bleeding (4.8%), hemodynamic instability (4.8%), and coronary occlusion/impingement (3.6%). At 30-day follow-up, the most common complications were new pacemaker (5.9%), cardiac failure (5.4%), and temporary renal failure requiring hemofiltration (10.1%).

Walther said that TAVR was a "clear success story. It’s a minimally invasive off-pump and very safe procedure right now," with excellent steerability and low stroke risk. Through the learning experience of TRAVERSE, researchers have improved results, particularly by employing a team approach that involves cardiac surgeons, cardiologists, and anesthesiologists, he said.

Lessons from REVIVAL II

Todd M. Dewey, MD, of Medical City Dallas in Texas, discussed the U.S. experience with transapical AVR as captured by the REVIVAL II feasibility study, previously published in the July 2008 issue of the Annals of Thoracic Surgery. In addition to measuring the safety and efficacy of the device, feasibility studies also must perfect the procedure itself, Dewey said.

"We learned early on that patient selection can be limited [by current risk assessment tools]," he said. Predictive factors include pulmonary disease, emphysema, and frailty. "There are patients that are too high risk for transapical AVR. When we started, we thought we had a tool [that] could treat everybody. We quickly learned that there are patients who are still too sick," Dewey said, adding that his group subsequently modified the selection criteria.

Disclosures:

• Dr. Webb reports serving as a consultant for Edwards Lifesciences.
• Dr.Walther reports no relevant conflicts of interest.
• Dr. Dewey is a consultant for Edwards Lifesciences.