Evolocumab is a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor which has been shown in the Fourier Trial to reduce major cardiovascular events in statin-treated patients with raised LDL cholesterol compared to placebo. The precise mechanisms via which evolocumab therapy impacts cardiovascular outcomes remain unknown. Coronary blood flow is a powerful predictor of clinical outcomes across a wide range of cardio-circulatory disorders as well as within normal subjects. Improvement in coronary microvascular function and coronary flow, therefore, could potentially represent one of the core pathways via which evolocumab offers cardiovascular protection. In the CHORAL Flow Study patients will undergo invasive and non-invasive physiological assessment with coronary flow measurements before and after 12 weeks of therapy with evolocumab or placebo. Patients in the treatment arm will go on to have a further non-invasive assessment of coronary flow at 24 weeks of therapy in a single blinded fashion.
CHORAL Flow is a randomised, double blinded, placebo-controlled trial of the effects of evolocumab on coronary flow at 12 weeks.