Cardiac MR guided TAVR effective option to CT-guided TAVR

For guiding TAVR, CT is recommended, but since TAVR candidates have chronic kidney disease (CKD), using iodinated contrast media poses a limitation. CMR could be a promising alternative but requires data to clarify "How effective is CMR- versus CT-guided TAVR?" This background was further investigated in the present study. Researchers conducted a trial at two Austrian heart centres.

Based on inclusion (severe symptomatic aortic stenosis) and exclusion criteria (contraindication to CMR, CT, or TAVR, a life expectancy < 1 year, CKD 4 or 5), patients were evaluated for TAVR. These were randomized to a 1:1 ratio for CMR- or CT-guiding. The primary outcomes measured were, absence of procedural mortality, correct positioning of a single prosthetic valve and proper prosthetic valve performance.

These were defined based on the Valve Academic Research Consortium-2 definition of implantation success at discharge. Non-inferiority was assessed using a hybrid modified intention-to-treat (mITT)/per-protocol (PP) approach (absolute risk difference margin of 9%).

The key results of the study are:

• Three hundred eighty candidates for TAVR were randomized to CMR-guided and CT-guided TAVR planning, including 191 and 189 patients.
• 72.3 % and 68.3 % in the CMR and CR guided group underwent TAVR, respectively. This included 138 patients and 129 patients, respectively.
• 267, 19 patients had protocol deviations, resulting in a PP cohort of 248, including 121 and 127 patients in CMR-guided and CT-guided, respectively.
• In the mITT cohort, implantation success was achieved in 129 patients and 117 patients in the CMR and CT group, constituting 93.5% and 90.7%, respectively.
• The between-group difference recorded was 2.8%.
• The between-group difference was 2.0% for the PP cohort.

They concluded the study by saying, "In our study, we report non-inferiority of CMR-guided TAVR to CT-guided TAVR pertaining to device implantation success."

CMR could be an alternative for TAVR planning, they noted.

Further reading:

https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.123.066498