Читать книгу Interventional Cardiology - Группа авторов - Страница 268

Over the last decade, TAVR has revolutionized the management of aortic stenosis. The aortic and mitral valves are well visualized on CTA [1], which is why CTA is now considered the imaging gold standard for pre‐TAVR evaluation and is increasingly being used for pre‐TMVR evaluation as well. A pre‐TAVR CT is a comprehensive study. The thoracic portion of the contrast‐enhanced study is ECG‐gated and must cover the aortic root to allow for appropriate measurements of the aortic annulus, sinuses of Valsalva, heights of the coronary ostia from the annulus, sinotubular junction and fluoroscopic angle. The abdominal and pelvic portion is used to measure iliofemoral and subclavian vessel size and is not ECG‐gated. Cardiac CT also plays a significant role in predicting new persistent left bundle branch block (NP‐LBBB) post‐TAVR. Two recent studies evaluated the CT‐based predictors of NP‐LBBB in patients undergoing TAVR using an Edwards Sapien 3 (S3) or EVOLUT R/PRO valve. The first study found that advanced age, a higher NTI, or Non tubular index (lower NTI is an indicator of a more tubular LVOT), more annular calcification on the right coronary cusp, implant depth at the non coronary cusp and LVOT oversizing >10% are independent predictors of NP‐LBBB when the S3 valve was used [47]. The second study found that shorter membranous septum length, LVOT eccentricity, annular oversizing, and deeper implant length were independent predictors of NP‐LBBB when the Evolut valve was used [48]. Additionally, a recent study used a cardiac CT‐based model to predict patient prosthesis mismatch (PPM) in patients undergoing TAVR using the Sapien 3 or Evolut R/Pro valves based on the aortic root anatomy. Severe PPM is a predictor of mortality and using cardiac CT to choose the appropriate valve could potentially reduce the incidence of PPM and in turn, play a significant role in improving overall survival of patients post‐TAVR [49]. Although routine post‐TAVR CT is not currently recommended, it should be considered if there is suspicion for endocarditis, valve thrombosis, or structural degeneration [50] (Figure 10.2a–c).