Utility of Multidetector Computed Tomographic Angiography as an
Alternative to Transesophageal Echocardiogram for Preoperative
Transcatheter Mitral Valve Repair Planning
Background: Transesophageal echocardiogram (TEE) is the
gold-standard for diagnosis of degenerative mitral regurgitation (MR)
and is used for guidance of transcatheter mitral valve repair (TMVr).
However, TEE is an invasive diagnostic modality that requires anesthesia
and esophageal intubation. Multi-detector computed tomographic
angiography (MDCT) provides high resolution images and three dimensional
(3D) reconstructions that allow for comprehensive assessment of complex
mitral anatomy. We hypothesized that MDCT can yield similar information
to 3D TEE relevant to TMVr, deferring the need for a preoperative TEE.
Methods: Patients that underwent TMVr (or were evaluated for
transcatheter mitral valve replacement) for degenerative MR were
retrospectively analyzed from 2017 to 2019 at a single center. Patients
were included in the analysis if preoperative MDCT was performed. Two
experienced TEE and two MDCT readers, blinded to patient outcome and
alternative imaging modality, analyzed the following characteristics:
leaflet pathology (flail, degenerative, mixed), leaflet location
(A1-3/P1-3), mitral valve area (MVA), flail width/gap,
anterior-posterior (AP) and commissural diameters, posterior leaflet
length, leaflet thickness, presence of mitral valve cleft and degree of
mitral annular calcification (MAC). Results: Of the 87
patients, 22 had preoperative MDCT. MDCT was able to correctly identify
the leaflet pathology in 77% (17/22). Eleven patients had a flail
leaflet with 91% (10/11) identified on MDCT and MDCT correctly
predicted the dysfunctional leaflet location in 95% (21/22).
Measurements were not significantly different for MVA, flail width,
commissural diameter, AP diameter, posterior leaflet length and leaflet
thickness. However, measurements on MDCT were significantly
overestimated for flail gap compared to TEE. Degree of MAC was similar
in 91% (10/11) between imaging modalities. Conclusion: MDCT
provides similar measurements to 3D TEE for preoperative TMVr planning.
Further studies are required to establish novel imaging algorithms
utilizing MDCT to reduce the need for preoperative TEE.