INTRODUCTION
There is an increasing body of evidence linking coronary microvascular dysfunction (CMD) with left ventricular (LV) diastolic dysfunction and a future risk of developing heart failure (HF) with preserved ejection fraction (HFpEF).1–3 This is of clinical significance as it has been recently shown that patients with CMD-associated diastolic dysfunction have an up to three-fold increased mortality rate and up to five-fold risk of developing a major adverse cardiovascular event (MACE).4 Previous studies have also reported similar changes in the echocardiographic indices of diastolic dysfunction in patients with CMD including reduction in left ventricular (LV) early diastolic strain rate, early volumetric filling rate and elevated LV filling pressures.5,6 However, there is a relatively limited amount of published research in this area regarding the relationship between CMD and LV diastolic function. A better understanding could help target future therapies against this condition. This study sought to investigate whether there was an association between CMD and LV diastolic function in a group of patients presenting with CPUCA.