Heart Valve Center, New York University Langone Medical Center, New York, New York.
MedStar Cardiovascular Research Network at Washington Hospital Center, Washington DC.
JACC Cardiovasc Imaging. 2017 Apr;10(4):461-470. doi: 10.1016/j.jcmg.2017.02.005.
Subclinical leaflet thrombosis was recently described in a randomized trial of transcatheter aortic valve replacement. It was subsequently demonstrated in a series of registries that this was a commonly observed imaging finding seen in all transcatheter and surgical bioprostheses. The phenomenon has aroused considerable interest due to the as-yet-undefined risk for later clinical events and the possibility of pharmacological intervention with anticoagulation. Subclinical leaflet thrombosis is easily detected noninvasively by technically suitable computed tomography (CT) with a high degree of concordance to transesophageal echocardiography findings. The CT hallmarks were noted to be hypoattenuated leaflet thickening (HALT) associated with reduced leaflet motion (RELM). The combination of HALT and RELM signified hypoattenuation affecting motion, the standardized imaging endpoint used. This paper describes the systematic CT evaluation methodology that was devised during the Portico trial investigation and U.S. Food and Drug Administration submission; it also highlights the need for an ongoing discussion among experts to enable, with the help of the Valve Academic Research Consortium, standardization of reporting of this imaging finding to cater to the present and future needs of clinical trials.
亚临床瓣叶血栓形成最近在经导管主动脉瓣置换术的随机试验中被描述。随后在一系列注册研究中证明，这是一种常见的影像学发现，见于所有经导管和外科生物瓣。由于尚未确定的晚期临床事件风险以及抗凝药物治疗的可能性，这种现象引起了相当大的兴趣。亚临床瓣叶血栓形成可以通过技术上合适的计算机断层扫描（CT）无创地检测到，与经食管超声心动图检查结果具有高度一致性。CT 的特征是瓣叶变薄（HALT）伴瓣叶运动减少（RELM）。HALT 和 RELM 的组合表示影响运动的低衰减，这是使用的标准化成像终点。本文描述了在 Portico 试验研究和美国食品和药物管理局提交期间设计的系统 CT 评估方法；它还强调了需要专家之间进行持续讨论，以便在瓣膜学术研究联合会的帮助下，标准化该影像学发现的报告，以满足当前和未来临床试验的需求。
