Previously implanted mitral surgical prosthesis in patients undergoing transcatheter aortic valve implantation: Procedural outcome and morphologic assessment using multidetector computed tomography

Transcatheter aortic valve implantation (TAVI) in the presence of a preexisting mitral prosthesis is challenging and its influence on the morphology of mitral prosthesis and the positioning of transcatheter heart valve (THV) is unknown. We assessed the feasibility of TAVI for patients with preexisting mitral prostheses, its influence on mitral prosthesis morphology, and the positional interaction between a newly implanted THV and mitral prosthesis using serial multidetector computed tomography (MDCT). Thirty-one patients with preexisting mitral prosthesis undergoing TAVI were included. MDCT was performed before and after TAVI. Thirty patients successfully underwent TAVI without interference from preexisting mitral prosthesis. Although opening disturbance of the mechanical mitral prosthesis by the THV edge was observed in 1 patient, the patient was managed conservatively. No THV embolization occurred. THV shift during deployment occurred in 9 patients and was predicted by a larger aortic annulus area (odds ratio: 1.24 per 10 mm2, 1.03–1.49, p = 0.02), possibly because of large THVs. The mitral mean pressure gradient was slightly higher after TAVI (3.7 vs. 4.3 mmHg, p = 0.002), whereas the mitral regurgitation grade was similar. MDCT showed that the size of the mitral prosthesis housing was unchanged after TAVI. The median distance between the mitral prosthesis and THV was 2.6 mm. The postprocedural angle between the mitral prosthesis and THV was larger than the preprocedural angle between the mitral prosthesis and the left ventricular outflow tract (64° vs. 61°, p = 0.03). Thus, TAVI is feasible in the case of preexisting mitral prosthesis. Serial MDCT demonstrated favorable THV positioning and unchanged mitral prosthesis morphology after TAVI.经导管主动脉瓣植入术（Transcatheter aortic valve implantation, TAVI）在合并既往二尖瓣假体植入的患者中极具挑战性，其对二尖瓣假体形态及经导管心脏瓣膜（transcatheter heart valve, THV）定位的影响尚不明确。本研究借助系列多层螺旋计算机断层扫描（multidetector computed tomography, MDCT），评估了合并既往二尖瓣假体的患者接受TAVI的可行性、该手术对二尖瓣假体形态的影响，以及新植入THV与二尖瓣假体间的位置相互作用。本研究共纳入31例既往植入二尖瓣假体并接受TAVI的患者，分别于TAVI术前及术后行MDCT检查。其中30例患者成功完成TAVI，未受既往二尖瓣假体的干扰。尽管有1例患者观察到THV边缘干扰机械二尖瓣假体的开放，但该患者接受了保守治疗，且未出现THV栓塞事件。9例患者在瓣膜释放过程中出现THV移位，该现象可通过更大的主动脉瓣环面积进行预测（优势比：每10mm²为1.24，95%置信区间1.03~1.49，p=0.02），其潜在原因可能为使用了尺寸较大的THV。TAVI术后二尖瓣平均压力梯度略有升高（3.7 mmHg vs 4.3 mmHg，p=0.002），而二尖瓣反流分级无明显差异。MDCT检查结果显示，TAVI术后二尖瓣假体容纳腔的尺寸未发生改变，二尖瓣假体与THV之间的中位间距为2.6mm。术后二尖瓣假体与THV之间的夹角较术前二尖瓣假体与左心室流出道之间的夹角更大（64° vs 61°，p=0.03）。综上，合并既往二尖瓣假体的患者接受TAVI具有可行性。系列MDCT检查证实，TAVI术后THV定位良好，二尖瓣假体形态无变化。