Anatomic suitability for transapical transcatheter mitral valve implantation using a tether-based device

BACKGROUND: Transcatheter mitral valve implantation (TMVI) is a novel therapeutic option for treating symptomatic mitral valve disease. Evaluating patient anatomical suitability is a critical step in the TMVI screening process, but currently requires specialized software and computerized device models.

AIMS: This analysis sought to assess the effectiveness of simple and standardized multislice computed tomography (MSCT) anatomic measurements for their ability to discriminate between patients who passed anatomical screening for Tendyne™ TMVI.

METHODS: Subjects screened for the Tendyne Expanded Clinical Study from January 2016 through September 2019 were included. Core laboratory screening measurements included mitral annular (MA) dimensions at end-systole and end-diastole, simulated device implantation, and neo-left ventricular outflow tract (LVOT) area. Additionally, nine standard measurements of patient anatomy were assessed for their predictive value of patients passing the anatomic screening process.

RESULTS: Out of 496 subjects screened for eligibility, 257 subjects met clinical eligibility criteria with MA dimensions within the manufacturer's suggested range: 153 (59.5%) underwent TMVI while 104 (40.5%) were excluded from the study for other anatomic reasons (76% due to risk of LVOT obstruction). CT-derived left ventricular end-systole diameter (LVESD) had the highest discriminatory power for predicting TMVI anatomical suitability (area under the curve of 0.908, p < 0.0001). The mitral inter-commissural (IC) dimension was best predictive of annular dimensions being within range, with dimensions <30 or >50 mm resulting in a negative predictive value of 94.4%.

CONCLUSIONS: MSCT-derived mitral IC dimension and LVESD easily performed measures that are effective predictors of anatomical suitability or screen failure for this tether-based TMVI device.