Transcatheter mitral valve replacement: factors associated with screening success and failure

AIMS: Transcatheter mitral valve replacement (TMVR) is a promising therapeutic solution to treat high-risk patients with severe mitral regurgitation (MR) contraindicated to surgery. Optimal selection of patients who will benefit from the procedure is of paramount importance. We aimed to investigate factors associated with TMVR screening. METHODS AND RESULTS: From November 2016 to July 2018, we examined conditions associated with TMVR screening success in patients referred to the two French heart valve clinics with the greatest TMVR experience. Among a total of 40 consecutively screened patients, 16 (40%) were selected for TMVR (8 Twelve Intrepid, 7 Tendyne and 1 HighLife), while 24 patients (60%) were refused for TMVR mainly because of a too large mitral annulus (MA) (n=15, 62% of those refused), or too small anatomy and risk of neo-left ventricular outflow tract (LVOT) obstruction (n=6, 25% of those refused). Patients with suitable anatomy for TMVR were more often male and more frequently suffered from secondary MR (p=0.01) associated with previous myocardial infarction and presented a commissure-to-commissure diameter less than 39 mm (AUC=0.72, p=0.0085) and LVESD greater than 32 mm (AUC=0.83, p<0.0001) on transthoracic echocardiography, and an MA area less than 17.6 cm² (AUC=0.95, p<0.0001) and anteroposterior diameter greater than 41.6 mm (AUC=0.87, p<0.001) on CT scan. CONCLUSIONS: Despite several prostheses being available, most patients referred to heart valve clinics who are good candidates with regard to their clinical profile cannot have TMVR because of mismatch between their anatomy and prosthesis characteristics. Our findings suggest the need to develop new prostheses adapted to larger mitral annuli but with a lower impact on the LVOT.