Potential exacerbation of systolic anterior motion during transcatheter mitral edge-to-edge repair

Transcatheter mitral edge-to-edge repair (M-TEER) is an effective treatment option for patients with severe mitral regurgitation (MR), but systolic anterior motion (SAM) and the related left ventricular outflow tract obstruction (LVOTO) may be unmasked or exacerbated after reconstruction of mitral leaflet coaptation.1,2 An 86-year-old woman presented with decompensated heart failure and severe degenerative MR with a flail P2 segment (Figure A, Supplementary data online, Video S1). Echocardiography demonstrated provocable SAM with LVOTO; the peak gradient increased to 114 mmHg. Simultaneous left ventricular–aortic pressure recording confirmed a minimal resting gradient (10 mmHg) but a provocable gradient of 69 mmHg. Given high surgical risk, M-TEER was performed using the MitraClip G4 XT system (Abbott Vascular, Santa Clara, CA). A first XT clip was deployed at the lateral A2-P2 segment (Figure B, Supplementary data online, Video S2). MR decreased to moderate; however, systolic blood pressure dropped with worsening SAM of the mitral valve and deployed clip (Figure B, arrow head). The peak-to-peak gradient rose to 82 mmHg at rest (Figure C) and 159 mmHg after a premature ventricular contraction. A second XT clip was implanted at the medial A2-P2 segment, where a leaflet-to-septal contact occurred earliest (Figure D, Supplementary data online, Video S3). After deployment, MR improved to mild grade without SAM and LVOTO (Figure E and F, Supplementary data online, Video S4), and the gradient decreased to 16 mmHg at rest and 37 mmHg under Valsalva on echocardiography at discharge (see Supplementary data online, Video S5).