Cardiac Magnetic Resonance Imaging Versus Computed Tomography to Guide Transcatheter Aortic Valve Replacement (TAVR-CMR): A Randomized, Open-Label, Non-Inferiority Trial
Martin Reindl, Ivan Lechner, Magdalena Holzknecht, Christina Tiller, Priscilla Fink, Fritz Oberhollenzer, Sebastian von der Emde, Mathias Pamminger, Felix Troger, Christian Kremser, Elisabeth Laßnig, Kathrin Danninger, Ronald K. Binder, Hanno Ulmer, Christoph Brenner, Gert Klug, Axel Bauer, Bernhard Metzler, Agnes Mayr, Sebastian Johannes Reinstadler- Physiology (medical)
- Cardiology and Cardiovascular Medicine
Background: Computed tomography (CT) is recommended for guiding transcatheter aortic valve replacement (TAVR). However, as a sizable proportion of TAVR candidates have chronic kidney disease (CKD), the use of iodinated contrast media is a limitation. Cardiac magnetic resonance (CMR) is a promising alternative, yet randomized data comparing the effectiveness of CMR- versus CT-guided TAVR are lacking.
Methods: An investigator-initiated, prospective, randomized, open-label, non-inferiority trial was conducted at two Austrian heart centers. Patients evaluated for TAVR according to the inclusion (severe symptomatic aortic stenosis) and exclusion criteria (contraindication to CMR, CT, or TAVR, a life expectancy < 1 year, CKD 4 or 5) were randomized (1:1) to undergo CMR- or CT-guiding. The primary outcome was defined according to the Valve Academic Research Consortium-2 definition of implantation success at discharge, including absence of procedural mortality, correct positioning of a single prosthetic valve, and proper prosthetic valve performance. Non-inferiority was assessed using a hybrid modified intention-to-treat (mITT)/per-protocol (PP) approach based on an absolute risk difference margin of 9%.
Results: Between September 11, 2017, and December 16, 2022, 380 candidates for TAVR were randomized to CMR-guided (191 patients) or CT-guided (189 patients) TAVR planning. Of these, 138 patients (72.3%) in the CMR-guided group and 129 patients (68.3%) in the CT-guided group eventually underwent TAVR (mITT cohort). Of these 267, 19 patients had protocol deviations, resulting in a PP cohort of 248 patients (n=121 CMR-guided, n=127 CT-guided). In the mITT cohort, implantation success was achieved in 129 patients (93.5%) in the CMR group and in 117 patients (90.7%) in the CT group (between-group difference, 2.8%; 90% confidence interval [CI]: -2.7 to 8.2%; p<0.01 for non-inferiority). In the PP cohort (n=248), the between-group difference was 2.0% (90% CI: -3.8 to 7.8%; p<0.01 for non-inferiority).
Conclusions: CMR-guided TAVR was non-inferior to CT-guided TAVR in terms of device implantation success. CMR can therefore be considered as an alternative for TAVR planning.