1469Left atrial remodelling in hypertrophic cardiomyopathy, contributing factors and associated outcomes

Background: In hypertrophic cardiomyopathy (HCM), left atrial (LA) dilation is associated with increased risk of atrial fibrillation (AF), heart failure and cardiac arrest. However, the factors which influence LA remodelling are not well described. Purpose: To describe the rate of LA remodelling, associated factors and subsequent clinical outcomes in HCM. Methods: Baseline and follow-up echocardiograms (2-dimensional, Doppler, tissue Doppler indices - TDI) were analysed by an experienced echocardiographer blinded to clinical factors or outcomes in an HCM cohort followed by an established adult centre. Patients were excluded if there was <1 year between first and last echocardiogram, AF was present before follow-up echocardiogram, prior myectomy, or for poor image quality. Clinical features and associated outcomes were obtained from medical records. The rate of LA remodelling was calculated by dividing the change in size by the time (in years) between studies. Multivariable linear and logistic regression were used to identify factors associated with LA remodelling and incident AF after controlling for age and body surface area (BSA).