The ViKTORIES trial: a randomised, double-blind, placebo-controlled trial of vitamin K supplementation to improve vascular health in kidney transplant recipients.Lees, J. S., et al.
American Journal of Transplantation 2021 [record in progress].
This trial aimed to investigate the effects of vitamin K supplementation on vascular stiffness and calcification in renal transplant recipients.
Participants were randomised to either the vitamin K supplementation group or the placebo group.
90 adult kidney transplant patients (≥18 years).
The primary endpoint was the ascending aortic distensibility. The secondary endpoints included coronary artery calcification score (CACS), carotid-femoral pulse wave velocity and augmentation index, cardiac structure and function, office blood pressure, electrocardiogram (ECG), calcium metabolism and bone turnover markers, transplant function, proteinuria, and quality of life.
This double-blind placebo-controlled phase II study investigated the role of Vitamin K supplementation in kidney transplant recipients (KTR) on surrogate markers of cardiovascular disease. The authors found no difference in vascular stiffness or calcification following 1 year of treatment, leading them to conclude that in an unselected cohort of KTRs, supplementation does not affect markers of cardiovascular risk and is unlikely therefore to have a significant impact on incidence of cardiovascular events. The study is very well designed and reported. Whilst the sample size is small, it does appear adequately powered to detect a clinically significant difference in the primary endpoint selected, and therefore the conclusions are justified. It is likely that supplementation alone in a general transplant population is unlikely to have a significant impact, so further study is required to see if there is benefit in a patient population with a deficiency in vitamin K at baseline.