Left atrial remodelling and function in various left ventricular hypertrophic phenotypes.

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

Methods and results: Patients with LV hypertrophy who underwent cardiac magnetic resonance (CMR) were compared to a control group. CMR data were analysed 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 with hypertrophic cardiomyopathy (HCM), 35 with cardiac amyloidosis (CA), 41 with hypertensive (HTN) heart disease, 97 with 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 ± 16.9 mL/m2, 46.8 ± 16.4 mL/m2, and 83.2 ± 2.1%, respectively). Patients with CA presented a higher LACI when compared with other groups (58 ± 2% vs. 42 ± 2% in HCM, 39 ± 2% in HTN heart disease, 37 ± 2% in AS, and 22 ± 1% in normal), while no differences were observed across others. Patients with CA 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 with 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).

Conclusion: 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.