Rapid Fire Abstract session: novelties in valves regurgitation831Significant functional mitral regurgitation impairs left atrial function in patients with heart failure due to left ventricular systolic dysfunction832Arterial stiffness and mitral regurgitation: an intriguing pathophysiological link833Progression rate of mild and moderate aortic regurgitation in a physiologist led valve clinic834The blood flow complexity affect the reliability of aortic regurgitation assessment by phase-contrast magnetic resonance imaging835Two-dimensional phase-contrast magnetic resonance imaging can describe the complexity of flow in ascending aorta in patients with aortic regurgitation836A cross-sectional study of endocardial lead-related tricuspid regurgitation: towards proposing a new practical 2D/3D echocardiographic approach for better risk stratification837Prognostic value of cardiac magnetic resonance for preoperative assessment of patients with severe functional tricuspid regurgitation

Purpose: Left atrial function (LAF) has emerged as a novel determinant of clinical status and outcomes in heart failure (HF).Significant functional mitral regurgitation (SFMR) is an important and prevalent pathophysiological and prognostic factor in this patient population, yet its effects on LAF are poorly understood.Aim of this study was to explore the possible interplay between the severity of functional MR and reduced LAF in patients with systolic HF.Methods: Echocardiography was performed in 93 patients (age 61 + 15 yrs) with HF (NYHA functional class II-IV) due to left ventricular systolic dysfunction (LVEF ≤ 40%), sinus rhythm, and mild to severe functional mitral regurgitation; subjects with any evidence of organic mitral valve disease were excluded.MR severity was estimated using a multiparametric approach, and patients were dichotomized based on the presence of SFMR (3-4+).LV and LA volumes were evaluated using Simpson's biplane method.LA volumes were measured at three time-points: just before mitral valve opening, at P-wave onset, and at mitral valve closure.According to previously described formulas, the different components of LA function were calculated: total LA emptying function (TLAEF), LA reservoir function (LAEI), LA passive emptying fraction (conduit function, LAPEF), and LA active emptying fraction (contractile function, LAAEF).Results: The two groups (SFMR -/+) were well matched in terms of demographics, HF etiology, and LV systolic function (29.3 + 9.7 vs 28.1 + 7.2 %).Patients with SFMR displayed worse clinical status (NYHA 2.19 + 1.00 vs 2.72 + 0.98; p,0.02), larger LV (LVEDVi 100 + 32 vs 128 + 38 ml/sqm; p=0.001) and LA volumes (maximal LAVi 38 + 20 vs 57 + 27 ml/sqm; p=0.001) compared to those without SFMR.LA reservoir (63 + 40 vs 35 + 26 %; p=0.006) and contractile function (21 + 14 vs 12 + 11 %; p,0.02) were significantly more impaired in patients with SFMR, while no difference was found in terms of LA conduit function (18 + 13 vs 17 + 18 %; p=ns).LAF was inversely correlated with NYHA functional class.Conclusions: The presence of SFMR seems to significantly affect left atrial reservoir and contractile function in patients with LV systolic dysfunction, independently of LVEF.Further research will elucidate the prognostic and therapeutic interactions between LA dysfunction and SFMR in the HF population.