The data will be extracted onto a pre-made excel spreadsheet (Office 365, Microsoft Corporation) with subheadings for study type, single or multi-centre, study drugs, and population characteristics: age, sex, hypertension, diabetes, heart failure, left atrium (LA) size, left ventricular ejection fraction (LVEF), maximal wall thickness, left ventricular outflow tract (LVOT) gradient, and follow-up duration.