Background:Although transcatheter aortic valve replacement (TAVR) therapy continues to grow, there have been concerns about the occurrence of hypoattenuating leaflet thickening (HALT), which may affect prosthesis function or durability. This study aimed to examine prosthesis frame factors and correlate their extent to the frequency of HALT and clinical outcomes.Methods:We prospectively examined 565 patients with cardiac computed tomography screening for HALT at 30 days after balloon-expandable SAPIEN3 and self-expanding EVOLUT TAVR. Deformation of the TAVR prostheses, asymmetric prosthesis leaflet expansion, prosthesis sinus volumes, and commissural alignment were analyzed on the postprocedural computed tomography. For descriptive purposes, an index of prosthesis deformation was calculated, with values >1.00 representing relative midsegment underexpansion. A time-to-event model was performed to evaluate the association of HALT with the clinical outcome.Results:Overall, HALT was present in 21% of SAPIEN3 patients and in 16% of EVOLUT patients at 30 days after TAVR. The occurrence of HALT was directly associated with greater prosthesis frame deformation (P<0.001), worse asymmetry of the leaflets (P<0.001), and smaller TAVR neosinus volumes (P<0.001). These relations were present in both prosthetic types and in all of their size ranges (all P<0.05). In multivariable analyses that include clinical variables previously associated with HALT (eg, anticoagulant therapy), variables of TAVR prosthesis deformation remained predictive of HALT. Although HALT was not associated with changes in prosthetic hemodynamics, its presence was associated with the risk of mortality at 1 year, with respect to greater incidences of all-cause mortality (hazard ratio, 2.98 [95% CI, 1.57–5.63]; P=0.001), cardiac death (hazard ratio, 4.58 [95% CI, 1.81–11.6]; P=0.001), and a composite outcome of all-cause mortality and heart failure hospitalization (hazard ratio, 1.94 [95% CI, 1.14–3.30]; P=0.02) with adjustment for age, sex, and comorbidities.Conclusions:Nonuniform expansion of TAVR prostheses resulting in frame deformation, asymmetric leaflet, and smaller neosinus volume is related to occurrence of HALT in patients who undergo TAVR. These data may have implications for both prosthesis valve design and deployment techniques to improve clinical outcomes for these patients.

中文翻译：

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经导管主动脉瓣假体的变形：对低密度瓣叶增厚和临床结果的影响

背景：尽管经导管主动脉瓣置换术 (TAVR) 疗法不断发展，但人们一直担心低密度瓣叶增厚 (HALT) 的发生，这可能会影响假体功能或耐用性。本研究旨在检查假体框架因素并将其程度与 HALT 频率和临床结果相关联。方法：我们前瞻性地检查了 565 名在球囊扩张 SAPIEN3 和自扩张 EVOLUT TAVR 后 30 天进行心脏计算机断层扫描筛查 HALT 的患者。在术后计算机断层扫描上分析了 TAVR 假体的变形、不对称假体小叶扩张、假体窦体积和连合排列。出于描述目的，计算了假体变形指数，其值 > 1。00 表示相对中段扩张不足。执行事件发生时间模型以评估 HALT 与临床结果的关联。结果：总体而言，在 TAVR 后 30 天，21% 的 SAPIEN3 患者和 16% 的 EVOLUT 患者出现 HALT。HALT 的发生与较大的假体框架变形直接相关（P <0.001），小叶的不对称性更差（P <0.001），并且 TAVR neosinus 体积更小（P <0.001）。这些关系存在于两种假体类型及其所有尺寸范围内（所有P <0.05）。在包括先前与 HALT 相关的临床变量（例如，抗凝治疗）的多变量分析中，TAVR 假体变形的变量仍然可以预测 HALT。尽管 HALT 与假体血流动力学的变化无关，但它的存在与 1 年时的死亡率风险相关，即全因死亡率更高（风险比，2.98 [95% CI，1.57–5.63]；P =0.001），心源性死亡（风险比，4.58 [95% CI，1.81–11.6]；P=0.001)，以及全因死亡率和心力衰竭住院的复合结果（风险比，1.94 [95% CI，1.14–3.30]；P =0.02），并针对年龄、性别和合并症进行了调整。结论：非均匀扩展导致支架变形、瓣叶不对称和新窦体积变小的 TAVR 假体与接受 TAVR 的患者发生 HALT 相关。这些数据可能对人工瓣膜设计和部署技术产生影响，以改善这些患者的临床结果。