Abstract Body (Do not enter title and authors here): Description of Case: An 83-year-old woman with hypertrophic obstructive cardiomyopathy (HOCM) with systolic anterior motion (SAM) of the mitral valve presented to the Emergency Department with several weeks of progressively worsening dyspnea and was found to have acute hypoxemic respiratory failure. The patient was started on bilevel positive airway pressure and underwent aggressive diuresis. Transesophageal echocardiogram showed moderate aortic stenosis, HOCM with SAM of the mitral valve, a large P2 flail segment of the mitral apparatus with ruptured cords, and significant pulmonary vein flow reversal. Percutaneous transcatheter edge-to-edge repair (TEER) was pursued with intraoperative transesophageal echocardiograpic images demonstrating an excellent result with resultant mild mitral regurgitation and a mean transmitral diastolic gradient of 5-6 mmHg. Hemodynamic measurements at this time showed resolution of prior left ventricular outflow tract gradient (from 86 mmHg to 25 mmHg).

Discussion: This report highlights a unique case in which a patient with known HOCM with SAM of the mitral valve developed concomitant severe mitral regurgitation from a flail posterior leaflet, leading to acute hypoxemic respiratory failure that was repaired with TEER. Current nonpharmacologic interventions for HOCM include alcohol septal ablation/myectomy, though both of these are not without their own risks. Though the use of TEER has been approved for patients with symptomatic severe mitral regurgitation who are deemed inoperable or at high surgical risk with a life expectancy > 1 year, small studies have also reported the use of TEER in patients with HOCM for symptom improvement who were not candidates for septal reduction therapy. This case builds on prior reports supporting TEER as an option for patients with medication-refractory HOCM who are not candidates for surgical intervention, also highlighting that it can be done concomitantly to treat acute degenerative valvulopathies.