Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021

Abstract

Background Transcatheter aortic valve implantation (TAVI) has gained worldwide acceptance and implementation as an alternative therapeutic option in patients with severe aortic valve stenosis unable to safely undergo surgical aortic valve replacement. This transformative technique places the radiologist in a key position in the pre-procedural assessment of potential candidates for this technique, delivering key anatomical information necessary for patient eligibility and procedural safety. Recent trials also provide encouraging results to potentially extend the indication to patients with safer risk profiles. Method The review is based on a PubMed literature search using the search terms “transcatheter heart valve”, “TAVI”, “TAVR”, “CT”, “imaging”, “MR” over a period from 2010–2020, combined with personal comments based on the author’s experience. Results and Conclusion CT plays a prominent role in the pre-procedural workup, delivering as a true 3D imaging modality optimal visualization of the complex anatomy of the aortic root with simultaneous evaluation of the patency of the different access routes. As such, the contribution of CT is key for the determination of patient eligibility and procedural safety. This input is supplementary to the contributions of other imaging modalities and forms an important element in the discussions of the Heart Valve Team. Knowledge of the procedure and its characteristics is necessary in order to provide a comprehensive and complete report. While the role of CT in the pre-procedural evaluation is well established, the contribution of CT and MR and the clinical significance of their findings in the routine follow-up after the intervention are less clear and currently the subject of intense investigation. Important issues remain, including the occurrence and significance of subclinical leaflet thrombosis, prosthetic heart valve endocarditis, and long-term structural valve degeneration. Key Points: Citation Format

Comparison of a High-Pitch Non-ECG-Gated and a Prospective ECG-Gated Protocol for Preprocedural Computed Tomography Imaging Before TAVI/TAVR

“…Furthermore, the high-pitch non-ECG-gated CT protocol resulted in a significant reduction of radiation exposure of 55 % compared to the ECG-gated protocol (from 13.44 mSv to 6.07 mSv). Dose reduction may appear secondary as TAVI/TAVR is currently generally performed in an elderly patient population [30,31].…”

“…Furthermore, the high-pitch non-ECG-gated CT protocol resulted in a significant reduction of radiation exposure of 55 % compared to the ECG-gated protocol (from 13.44 mSv to 6.07 mSv). Dose reduction may appear secondary as TAVI/TAVR is currently generally performed in an elderly patient population 30 31 . Nevertheless, two recent clinical trials published in The New England Journal of Medicine in 2019 have established the noninferiority of TAVI/TAVR compared to SAVR in low-risk patients.…”

Management of coronary artery disease in patients undergoing transcatheter aortic valve implantation. A clinical consensus statement from the European Association of Percutaneous Cardiovascular Interventions in collaboration with the ESC Working Group on Cardiovascular Surgery

“…Notably, adenosine stressperfusion was performed without complications despite the presence of severe AS. When compared to MSCT, however, the CMR scan is technically more challenging and represents an additional step in the pre-TAVI pathway; hence, it should be reserved for specific indications, rather than as part of a routine workup 39 .…”