Treatment Patterns of Patients With Mitral Valve Disease and Critical Neo-LVOT Obstruction

Background and Aims: Among patients with severe mitral valve (MV) disease and predicted high-risk of left ventricular outflow track obstruction (LVOTO), the patterns of treatment and clinical outcomes have not previously described. The aim of this study was to explore outcomes of this patient population. Methods: We conducted a single-center study including all consecutive patients with severe MV disease who were evaluated by a multidisciplinary structural heart disease team for MV therapies between 2018 and 2023. All patients underwent pre-procedural contrast cardiac computed tomography (CT). We defined high risk for LVOTO as a post-transcatheter mitral valve replacement (TMVR) predicted neo-LVOT < 150 mm². Results: A total of 157 patients with a median Neo-LVOT of 0 (IQR 0−80.4) were included. Median age was 79 (72−83), and most were females (89.2%). A total of 59 patients (37.6%) had severe mitral stenosis, 48 (30.6%) had severe mitral regurgitation, and 98 (58%) had both. The median STS score was 22.6 (17–29.6). Most patients were in NYHA class III or IV (77.1%), and the median KCCQ-12 was 48.9 (IQR: 29–68.7). Overall, the majority of patients were assigned to medical therapy (54.1%). There were a total of 41 deaths (26.1%) at a median follow-up time of 247 days (IQR: 70−568). When separated into non-severe MAC and severe MAC, patients with severe MAC had higher rates of all-cause mortality at 1 year (unadjusted HR: 2.44; 95% CI: 1.13−5.24; p = 0.02). Severe MAC patients were more likely to be assigned to medical therapy. Treatment allocation was not independently associated with a higher or lower risk of death. Conclusions: Patients with severe MV disease at high-risk for LVOTO (LVOT < 150 mm²) after TMVR were overwhelmingly female and were most frequently assigned to medical therapy. Patients with severe MAC had higher rates of death. Treatment allocation was not independently associated with mortality. Novel transcatheter therapies are needed to definitively treat this high-risk population.