1110 prognostic impact of significant mitral regurgitation in patients with severe low flow, low gradient aortic stenosis undergoing transcatheter aortic valve replacement

Abstract Aim This study sought to determinate the prevalence, clinical impact, and clinical outcome of significant moderate-to-severe mitral regurgitation (MR) in patients with severe low flow, low gradient aortic stenosis (LFLG-AS) undergoing transcatheter aortic valve replacement (TAVR). Methods All consecutive patients with severe LFLG-AS undergoing TAVI in two high-volume Italian centres from 2013 to 2022 were prospectively included. LFLG-AS was defined as indexed aortic valve area (iAVA) ≤0.6 cm2/m2, mean transaortic gradient <40 mmHg and stroke volume index <36 ml/m2. LFLG-AS was classified as classical if left ventricular ejection fraction (LVEF) was <50%, and paradoxical in patients with preserved LVEF >50%. Demographic, clinical, instrumental, and procedural features were systematically collected by using an electronic case report form. MR severity was graded according to the current guidelines, and patients were categorized based on the MR severity at baseline in two groups: mild and moderate-to-severe MR. The primary study outcome was the composite of all-cause mortality and rehospitalization for worsening heart failure (HF) up to 1 year; secondary outcomes were the single components of the primary outcome. Results The study included 268 patients [81±6 years; 142 (53%) females]; moderate-to-severe MR was reported in 57 patients (21%). At baseline moderate-to-severe MR compared to those with mild MR showed statistically significant differences between age (p 0.008), female sex (p 0.007), hypertension (p 0.036), diabetes (p 0.001) atrial fibrillation/flutter (p 0.018) and chronic kidney disease (p 0.012). In the overall population, only one patient died during the hospitalization and at one-year follow-up, the primary outcome was reported in 49 patients (18%); all-cause death occurred in 26 (10%), and HF rehospitalization in 24 (9%). Regarding the two subgroups, Kaplan-Meier curves showed that survival free from the composite outcome was significantly lower in patients with moderate-to-severe MR compared to those with mild MR (Log Rank <0.001, Figure 1A). Survival free from all-cause mortality and HF rehospitalization was also significantly lower in patients with moderate-to-severe MR (Log-Rank <0.001 and Log-Rank=0.002, respectively; Figure 1B and 1C). Conclusion In this study, many patients with LFLG-AS undergoing TAVR had coexisting moderate-to-severe MR. TAVI confirmed a high safety profile, LFLG-AS patients showed a high incidence of adverse events up to 1 year, especially those with coexisting moderate-to-severe MR. Moderate-to-severe MR should be duly considered for better prognostic stratification and clinical management of these particular TAVR patients during follow-up. Figure 1