Left ventricular outflow tract gradient is associated with reduced capillary density in hypertrophic cardiomyopathy irrespective of genotype.

Background: Coronary microvascular dysfunction (CMD) is an important feature of hypertrophic cardiomyopathy (HCM), which contributes negatively to symptoms and long-term outcome. Previous in vivo imaging studies in HCM suggest that left ventricular outflow tract (LVOT) gradient and genetic status are important contributors to CMD. CMD may be caused by reduced capillary density.