A More Efficient Method of Patient Evaluation for TMVR: Planning for Best- and Worst-Case Position

Background: Left ventricular outflow tract (LVOT) obstruction is a life-threatening complication after transcatheter mitral valve replacement (TMVR), occurring in ∼10% of patients. To predict possible LVOT obstruction, virtual device implantation and anatomical assessment of computed tomography is used. This requires an estimation of valve position within the patient\u27s anatomy. Given the unpredictability of device deployment, it is important to consider potential best- and worst-case positions within the LVOT to make an appropriate decision about LVOT obstruction risk. Current computed tomography planning methods can be time-consuming (up to 90 min per cardiac phase), especially when multiple device positions must be evaluated. As TMVR becomes more common, patient planning must become more efficient. The objective of this work is to assess the efficiency of 3-dimensional TMVR planning in a novel software versus traditional methods. Methods: Three image analysts of varying skill levels independently performed a neo-LVOT assessment of 10 pre-operative computed tomography scans. For each scan, the operator created a 3-dimensional model of the cardiac anatomy and virtually sized and positioned a TMVR device in the mitral annulus using the Materialise Mimics Enlight software (Materialise Leuven, Belgium). To better understand potential LVOT obstruction risk, the virtual device was assessed in both optimal and suboptimal positions. The analysts then measured the neo-LVOT area using an automated method to determine smallest area. The time to perform the neo-LVOT assessment was recorded and compared between operators and to traditional assessment methods. Results: Time to complete neo-LVOT assessment in 2 device positions was found to be between 1 and 5 min, representing a time savings of at least 75% when compared with traditional methods. Skill level of the operator had no significant impact on assessment time. Conclusion: Pre-procedural assessment of the neo-LVOT evaluating multiple potential device positions is important for understanding risk of LVOT obstruction. Three-dimensional planning methods as demonstrated in the Mimics Enlight software can be an efficient method for performing such analyses