Anatomic Suitability for Transcatheter Mitral Valve Implantation Is Accurately Determined by Left Ventricular End Systolic Dimension

Background: Assessing anatomic suitability for transcatheter mitral valve implantation (TMVI) can be time-consuming, particularly simulation of the neo-left ventricular outflow tract (neoLVOT), requires specialized software and computerized models of prostheses. The objective of this study is to assess CT-derived patient anatomic measurements for their ability to accurately differentiate between patients who were treated in a TMVI clinical study and those who were excluded due to anatomic concerns.

Methods: From 2016 to 2019, a total of 496 patients were submitted for screening in the Tendyne TMVI (Abbott, Santa Clara, CA) Expanded Clinical Study and had CT anatomical measurements performed by an independent Core Laboratory. Subjects who met all study eligibility criteria and were deemed clinically appropriate for participation in the study were included in this analysis.

Result: Of 386 subjects meeting all study criteria, 129 had annular dimensions outside eligible and were excluded from analysis. The remaining 257 subjects comprised the primary analysis population: 153 (59.5%) underwent TMVI, and 104 (40.5%) were excluded from the study for anatomic reasons. Receiver operating characteristic (ROC) curves were constructed for 12 CT-measured anatomic variables. Of the 12 variables, left ventricular end systolic diameter (LVESD) was the most accurate differentiator, with an area under the curve of 0.908 (p < 0.0001). In the primary analysis cohort, 97.3% (1) of patients treated with TMVI had measured LVESD >40 mm, corresponding to 76.3% (145 of 190) of all screened patients with LVESD >40 being deemed anatomically suitable. Conversely, 93.3% (56 of 60) of patients with LVESD <40 mm were screen failed for anatomic reasons.

Conclusion: This analysis demonstrates feasibility a simple yet accurate CT-based screening method to assess anatomic suitability for TMVI. Of subjects meeting study eligibility criteria and possessing annular dimensions within the manufacturer's recommended ranges, 97.3% had LVESD of >40 mm, and 76.3% of patients with LVESD >40 mm were screen passed. Importantly, this approach does not require neoLVOT simulations or access to valve-specific computerized models. An analysis to determine if LVESD measured by transthoracic echocardiogram can also be used to determine anatomic eligibility for TMVI is ongoing and may further simplify TMVI screening in the future.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
19 February 2021