Vitamin K to Attenuate Coronary Artery Calcification in Hemodialysis Patients

At every stage of chronic kidney disease (CKD), the leading cause of mortality is cardiovascular disease. This is due, in part, to vascular calcification (VC) of the coronary arteries. The extent of VC in the coronary arteries of patients with CKD is commonly determined by high resolution CT scan. The total coronary artery calcium (CAC) score, measured in Agatston units (AUs), reflects the calcium burden in the three major coronary arteries and is the current standard for determining extent of vascular calcification in hemodialysis patients. Matrix Gla protein (MGP), a vitamin K dependent protein, is a key inhibitor of vascular calcification and is present in the arterial wall. It is established that MGP becomes up-regulated adjacent to sites of calcification and that vitamin K is critical to its function. Therefore vitamin K status may be critical to the extent of vascular calcification in this patient group. However, to date, no trial has examined whether vitamin K supplementation prevents the progression of coronary artery calcification in patients with kidney failure, a group in which high risk has been established. Therefore, our primary research question is: Does vitamin K supplementation with 10 mg of phylloquinone thrice weekly reduce the progression of coronary artery calcification (as measured by CAC score) over 12 months in prevalent hemodialysis patients with a baseline CAC score of ≥ 30 Agatston Units compared to placebo?