Cardiac magnetic resonance imaging versus computed tomography to guide transcatheter aortic valve replacement: study protocol for a randomized trial (TAVR-CMR)

Abstract

Background The standard procedure for the planning of transcatheter aortic valve replacement (TAVR) is the combination of echocardiography, coronary angiography, and cardiovascular computed tomography (TAVR-CT) for the exact determination of the aortic valve dimensions, valve size, and implantation route. However, up to 80% of the patients undergoing TAVR suffer from chronic renal insufficiency. Alternatives to reduce the need for iodinated contrast agents are desirable. Cardiac magnetic resonance (CMR) imaging recently has emerged as such an alternative. Therefore, we aim to investigate, for the first time, the non-inferiority of TAVR-CMR to TAVR-CT regarding efficacy and safety end-points. Methods This is a prospective, randomized, open-label trial. It is planned to include 250 patients with symptomatic severe aortic stenosis scheduled for TAVR based on a local heart-team decision. Patients will be randomized in a 1:1 fashion to receive a predefined TAVR-CMR protocol or to receive a standard TAVR-CT protocol within 2 weeks after inclusion. Follow-up will be performed at hospital discharge after TAVR and after 1 and 2 years. The primary efficacy outcome is device implantation success at discharge. The secondary endpoints are a combined safety endpoint and a combined clinical efficacy endpoint at baseline and at 1 and 2 years, as well as a comparison of imaging procedure related variables. Endpoint definitions are based on the updated 2012 VARC-2 consensus document. Discussion TAVR-CMR might be an alternative to TAVR-CT for planning a TAVR procedure. If proven to be effective and safe, a broader application of TAVR-CMR might reduce the incidence of acute kidney injury after TAVR and thus improve outcomes. Trial registration The trial is registered at ClinicalTrials.gov (NCT03831087). The results will be disseminated at scientific meetings and publication in peer-reviewed journals.

Cardiac Magnetic Resonance Imaging Versus Computed Tomography to Guide Transcatheter Aortic Valve Replacement: A Randomized, Open-Label, Noninferiority Trial

“…TAVR-CMR was an investigator-initiated, prospective, randomized, open-label, noninferiority trial carried out at 2 Austrian heart centers. 23 The trial was designed to evaluate the noninferiority of CMR compared with CT for guiding TAVR. Potential TAVR candidates meeting eligibility criteria and consenting to participation were randomly assigned in a 1:1 fashion to undergo either a predefined TAVR-CMR protocol or a standard contrast-enhanced TAVR-CT protocol to assess anatomic characteristics of the aortic annulus and access route.…”

“…In both study centers, CMR examinations were conducted with a 1.5-T clinical imaging unit (Magnetom AVANTO fit ; Siemens) as described previously. 23 In brief, the applied CMR protocol included a non–contrast-enhanced, ECG-triggered, navigator-gated, free-breathing 3-dimensional whole-heart acquisition using a steady-state free precession sequence covering the range between left ventricular outflow tract to the ascending aorta. For planning of this sequence, a cubic 3-dimensional volume was placed at the level of the bulbus aortae as defined at axial, coronal, and parasagittal localizers.…”

Pre-Procedural Assessment of the Femoral Access Route for Transcatheter Aortic Valve Implantation: Comparison of a Non-Contrast Time-of-Flight Magnetic Resonance Angiography Protocol with Contrast-Enhanced Dual-Source Computed Tomography Angiography

“…Further prospective, preferably randomized, studies are required before non-contrast MRA can be recommended for broader applications. In this context, data from an ongoing randomized trial are eagerly awaited [22].…”