Mitral Regurgitation and Severe Aortic Stenosis: Clinical Characteristics, Prognostic Impact, and Response to TAVR: Insights From Egnite Data

BACKGROUND: Aortic stenosis (AS) and mitral regurgitation (MR) frequently co-occur, complicating diagnosis and treatment. We examined current US treatment trends and patient outcomes among patients with severe AS and at least moderate MR. METHODS: We analyzed data from 2 992 362 patients (aged ≥18 years) undergoing 5 245 904 echocardiograms at 43 US institutions (Egnite Database; Egnite, Aliso Viejo, CA, with permissions) to identify a cohort of patients with severe AS and moderate or greater MR. The primary end point was 2-year all-cause mortality, assessed via Kaplan-Meier analysis. For patients undergoing transcatheter aortic valve replacement (TAVR) alone, MR severity changes from baseline to 45 days post-TAVR were visualized using Sankey diagrams. RESULTS: The cohort included 36 402 patients (mean age, 78.2 years; 54.6% male), of whom 52.0% were untreated, 36.5% underwent TAVR alone, and 11.5% underwent surgery or other transcatheter interventions. Two-year mortality for untreated patients was 36.8% (95% CI, 35.6%–38.0%) for AS with less than moderate MR, 57.3% (95% CI, 54.0%–60.6%) for AS with moderate MR, and 65.5% (95% CI, 60.9%–70.1%) for AS with moderate-to-severe or severe MR (log-rank P <0.001). Undertreatment was more frequent in patients with AS and significant MR (64.5% versus 49.9%, P <0.001). Among patients undergoing TAVR alone with follow-up MR data, 77.5% demonstrated improvement in MR. CONCLUSIONS: Patients with concurrent MR and AS exhibit substantially higher mortality yet have high rates of undertreatment throughout the duration of follow-up. TAVR alone significantly improves MR in most patients.