Author + information
- Ambarish Gopal, MD∗ (, )
- Paul A. Grayburn, MD,
- Molly Mack, BA,
- Isabel Chacon, RT,
- Rebeca Kim, BA,
- Debbie Montenegro, MS,
- Teresa Phan, MS,
- Jill Rudolph, RN, BSN,
- Giovanni Filardo, PhD, MPH,
- Michael J. Mack, MD and
- Deepika Gopalakrishnan, MD
- ↵∗Reprint requests and correspondence:
Dr. Ambarish Gopal, Heart Hospital Baylor Plano, Baylor Scott & White Healthcare System, 4717 Alliance Boulevard, Suite 340, Plano, Texas 75093.
- aortic annulus
- transcatheter aortic valve implantation
- transcatheter aortic valve replacement
- transcatheter heart valve therapy
Computed tomographic imaging has become the reference standard for aortic annulus sizing in patients evaluated for transcatheter aortic valve replacement. However, many of these patients have underlying renal dysfunction that precludes safe use of radiographic contrast. In such patients, free-breathing noncontrast, navigator-gated 3-dimensional magnetic resonance imaging whole-heart acquisition (nc-cMRI) data can be effectively used for 3-dimensional aortic annulus sizing. nc-cMRI is performed with a 1.5-T whole body magnetic resonance imaging scanner (Philips Achieva, Philips Healthcare, Andover, Massachusetts) using a 16-channel phased array heart synergy coil (shortest repetition time, shortest echo time, flip angle 90°). Reconstruction is on a 512 × 512 matrix resulting in a final voxel resolution of 0.59 × 0.59 × 0.75 mm3. In this prospective observational study with 35 consecutive eligible patients with severe aortic stenosis (Table 1), no significant propensity-adjusted differences in perimeter, area, and average, maximum, and minimum diameters were found between nc-cMRI and cardiac computed tomography angiography diastolic measurements. With the exception of the minimum annulus diameter being significantly smaller with nc-cMRI (difference = 0.4139, 95% confidence interval [CI]: 0.0721 to 0.7556, p = 0.02), similar results were observed when nc-cMRI was compared to cardiac computed tomography angiography end-systolic measurements. Figures 1 to 5⇓⇓⇓ document the step-by-step process of image analysis and measurement.
For patients in whom contrast administration is not advisable, nc-cMRI provides an accurate alternative to cardiac computed tomography angiography for annular sizing. The annulus perimeter and the average diameter vary less than the annulus area during cardiac cycle in patients with severe aortic stenosis, and are better suited to size the annulus before transcatheter aortic valve replacement.
Dr. A. Gopal has served as a consultant to Edwards Lifesciences. Dr. Grayburn has received research grants from Abbott Vascular, Medtronic, Aastrom, and Edwards; has received Echo Core Lab Contracts from Valtech Cardio, Tendyne, and Guided Delivery Systems; and has received consulting and/or speaker fees from Abbott Vascular, Tendyne, and Bracco Diagnostics. Ms. Rudolph has served as a nurse consultant to Edwards Lifesciences. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation