Functional mitral regurgitation and left atrial myopathy in heart failure with preserved ejection fraction

ABSTRACT Aims Mild to moderate functional mitral regurgitation (MR) is common in patients with heart failure and preserved ejection fraction (HFpEF) where it is usually considered as an innocent bystander. We hypothesized that MR in HFpEF reflects greater left atrial (LA) myopathy, leading to more adverse haemodynamics and poorer exercise reserve. Methods and results Patients with HFpEF (n = 280) with and without MR underwent echocardiography, invasive haemodynamic exercise testing, and expired gas analysis. As compared to non‐MR‐HFpEF (n = 163), patients with MR‐HFpEF (n = 117; 78 mild and 39 moderate, central jet in 90%) were older, more likely female, with lower body mass and higher prevalence of atrial fibrillation (AF). HFpEF patients with MR displayed greater LA volume, reduced LA strain and compliance, and greater mitral annular dilatation, which was strongly correlated with LA dilatation (r = 0.63, P