Yahagi Kazuyuki, Ladich Elena, Kutys Robert, Mori Hiroyoshi, Svensson Lars G, Mack Michael J, Herrmann Howard C, Smith Craig R, Leon Martin B, Virmani Renu, Finn Aloke V
CVPath Institute Inc, Gaithersburg, Maryland.
Cleveland Clinic, Cleveland, Ohio.
Catheter Cardiovasc Interv. 2017 Nov 15;90(6):1048-1057. doi: 10.1002/ccd.27160. Epub 2017 Jun 1.
The Placement of AoRtic TraNscathetER Valves trials (PARTNER) showed favorable safety and efficacy versus medical or surgical therapy in inoperable, high, and intermediate surgical risk patients with severe aortic stenosis. However, the biological responses to transcatheter aortic valves have not been well characterized.
The aim of this study was to perform pathologic assessment of Edwards SAPIEN transcatheter aortic valves removed either at autopsy or surgically during the PARTNER I and II clinical trials.
Explanted valves and frame were evaluated for pathologic responses including extent of thrombus, inflammation, neointima, and leaflet degeneration/calcification according to semiquantitative grading by implant duration (≤30 days; 31-90 days; >90 days).
A total of 22 cases (median age 82.0 years, 45% men) were included, with a duration of implantation that ranged from 0 to 1739 days (median duration 16.5 days [interquartile range, 2.8-68.3]). Valve thrombosis resulting in severe aortic stenosis was observed in one case. Moderate leaflet thrombus was seen in 14% of cases (n = 3) and all were asymptomatic. Calcification was seen in two valves: one with severe leaflet calcification had severe aortic stenosis requiring surgical replacement, while the other showed early calcification. Mild structural leaflet changes were exclusively seen in valve implants >90 days. Valve inflammation and thrombus formation was mild in majority of the cases.
Overall, our study demonstrates moderate thrombus formation in 14% and calcification in only 2 valves, ≥4 years duration. In this short-duration study, acceptable durability and biocompatibility of the Edwards SAPIEN transcatheter valve system was demonstrated; however, further studies are required to confirm the significance and application of our findings.
主动脉经导管瓣膜置入试验（PARTNER）表明，对于无法手术、手术风险高和中等的严重主动脉瓣狭窄患者，与药物或手术治疗相比，经导管主动脉瓣具有良好的安全性和有效性。然而，对经导管主动脉瓣的生物学反应尚未得到充分表征。
本研究的目的是对在PARTNER I和II临床试验期间通过尸检或手术取出的爱德华兹SAPIEN经导管主动脉瓣进行病理评估。
根据植入持续时间（≤30天；31 - 90天；>90天）的半定量分级，评估取出的瓣膜和框架的病理反应，包括血栓形成程度、炎症、新生内膜以及瓣叶退变/钙化情况。
共纳入22例患者（中位年龄82.0岁，45%为男性），植入持续时间为0至1739天（中位持续时间16.5天[四分位间距，2.8 - 68.3]）。1例患者出现瓣膜血栓形成导致严重主动脉瓣狭窄。14%的病例（n = 3）可见中度瓣叶血栓，且均无症状。2个瓣膜出现钙化：1个伴有严重瓣叶钙化的患者有严重主动脉瓣狭窄，需要手术置换，另1个显示早期钙化。仅在植入时间>90天的瓣膜中观察到轻度瓣叶结构改变。大多数病例的瓣膜炎症和血栓形成较轻。
总体而言，我们的研究表明，在≥4年的研究中，14%的患者出现中度血栓形成，仅2个瓣膜出现钙化。在这项短期研究中，证明了爱德华兹SAPIEN经导管瓣膜系统具有可接受的耐用性和生物相容性；然而，需要进一步研究来证实我们研究结果的意义和应用。
