Left Atrial Remodeling and Function in Various Left Ventricular Hypertrophic Phenotypes.

Abstract

Aims: How the underlying etiology and pathophysiology of left ventricular (LV) hypertrophy affects LA remodeling and function remains unexplored. The present study aims to investigate the influence of various hypertrophic phenotypes on LA remodeling and function.

Methods and results: Patients with LV hypertrophy who underwent cardiac magnetic resonance (CMR) were compared to a control group. CMR data were analyzed retrospectively to assess LA strain, volume, sphericity and left atrioventricular coupling index (LACI). Independent clinical associates of LA strain were assessed using multivariable linear regression analysis.A total of 375 individuals were included: 148 hypertrophic cardiomyopathy (HCM), 35 cardiac amyloidosis (CA), 41 hypertensive heart disease (HTN), 97 severe asymptomatic aortic stenosis (AS) and 54 with normal CMR. Indexed LA end-systolic (iLVmax), diastolic volumes and LA sphericity were the largest in patients with CA (59.1±16.9ml/m2, 46.8±16.4ml/m2 and 83.2±2.1%, respectively). CA patients presented higher LACI when compared to other groups (58±2% vs 42±2% in HCM, 39±2% in HTN, 37±2% in AS and 22±1% in normal), while no differences were observed across others. CA patients showed the lowest LA reservoir (9.6%[0.6-18.6%]) and booster strain (9.1±5.4%), whereas no differences were observed across other groups. LACI and iLAVmax were independently correlated to LA reservoir (β=0.15 and β=-39.33, respectively), LA conduit (β=0.08 and β =-17.08, respectively) and LA booster strains (β=0.1 and β=-28.69, respectively). LA sphericity was independently correlated with LA reservoir strain (β=-0.51). Finally, LV global longitudinal strain was independently correlated with LA reservoir (β=-0.43), conduit (β=-0.20) and booster strain (β=-0.24).

Conclusions: LA characteristics differ among LV hypertrophic phenotypes. LACI and iLAVmax are independently correlated with LA function while LA sphericity correlates independently with LA reservoir strain.