Clinical Characteristics and Outcomes of Patients Screened for but Deemed Clinically Not Suitable for Transcatheter...

Transcatheter therapies are a recognized alternative intervention in patients with severe mitral regurgitation who are at high surgical risk. The purpose of this study was to characterize patients screened for transcatheter mitral valve replacement (TMVR), establish the clinical and anatomic reasons for unsuitability, and determine clinical course and early outcomes.

International multicentre registry was conducted of consecutive patients screened for TMVR at 12 centres in Europe, the United States, and Canada between April 2015 and September 2018. Patient-level retrospective data were collected for all patients screened.

From a total of 294 patients, 87 (30%) patients were suitable for and underwent TMVR, whereas 207 (70%) patients were unsuitable for TMVR. There was no difference in Society of Thoracic Surgeons predicted risk of mortality (6.3% ± 4.3% vs 6.7 ± 6.1%, P = 0.52) for mitral valve replacement between the groups. The most common reasons for TMVR unsuitability were mitral annular size outside therapeutic range (28%) and small predicted neo-LVOT (25%). Preprocedural multidetector computed tomographic demonstrated that patients unsuitable for TMVR had smaller predicted neo-left ventricular outflow tract (LVOT) area (318 ±192 mm² vs 495 ± 202 mm², P = 0.04). At 30 days, there was no difference in rates of rehospitalization (8% vs 8%, P = 0.21), stroke (1% vs 2%, P = 0.42), or mortality (4% vs 10%, P = 0.10), unadjusted for procedural risk, between unsuitable for TMVR and TMVR groups, respectively.

Two-thirds of patients failed screening as anatomically unsuitable for TMVR. The findings of this study have important clinical implications, highlighting an unmet clinical need and provide a target for design innovation in future iterations of TMVR devices.