Estimation of Coronary Obstruction Risk for the Transcatheter Aortic Valve Implantation in Surgical Aortic Valve (TAV-in-SAV) Procedure.

Background: To consider transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) as a secondary intervention, the risk of coronary obstruction during future TAV-in-SAV should be assessed prior to initial SAV replacement (SAVR), especially in Japanese patients with a small body size and aortic root anatomy. In this study we simulated the risk of coronary obstruction and identified associated anatomical factors.

Methods and results: We retrospectively analyzed pre- and post-SAVR computed tomography scans of 115 patients and simulated the risk of coronary obstruction. High risk was defined as postoperative coronary arteries located below the risk plane (RP) and a valve-to-coronary distance <4 mm or a valve-to-aorta distance <2 mm; 28.7% of patients were classified as high risk. Preoperative right and left coronary artery heights of ≥22 and ≥18 mm, respectively, were important parameters for classifying patients with postoperative coronary arteries located above or below the RP. An expected valve-to-sinotubular junction (STJ) distance (defined as the difference between the preoperative STJ diameter and the expected internal valve diameter) ≥7 mm was another important parameter to stratify patients into low- and high-risk categories.

Conclusions: TAV-in-SAV was anatomically unfeasible in 28.7% of patients, and the coronary obstruction risk was associated with aortic root anatomy and implanted valve size. These results may provide a basis for considering TAV-in-SAV as a secondary option in Japanese patients with a small body size and aortic root anatomy.