Effect on Vascular Calcification of Replacing Warfarin by Rivaroxaban With or Without VitK2 in Hemodialysis Patients

The Effect of Replacement of Vitamin K Antagonist by Rivaroxaban With or Without Vitamin K2 Supplementation on Vascular Calcifications in Chronic Hemodialysis Patients: A Randomized Controlled Trial

This study examines patients on chronic hemodialysis with non-valvular atrial fibrillation, who have a CHA2DS2-VASc Score of ≥ 2 and therefore are candidates for or already receive a vitamin K antagonist.

The first question is whether replacement of the vitamin K antagonist by rivaroxaban is able to slow progression of vascular calcification. The second question is whether addition of vitamin K2 to rivaroxaban can further slow down or even halt the progression of vascular calcification.

The present study targets dialysis patients with non-valvular atrial fibrillation requiring treatment with vitamin K antagonists. It addresses the question whether replacement of the vitamin K antagonist by rivaroxaban is able to slow progression of vascular calcification (VC). The second research question is whether addition of vitamin K2 to rivaroxaban can further beneficially affect the progression of VC. Two non-invasive methods are used to evaluate the impact of interventions on the progression of VC: i.e. coronary artery calcification (CAC) and pulse wave velocity (PWV) measurements. The detection of CAC is predictive for the presence of obstructive coronary artery disease and future coronary events. VC and stiffening of the central elastic-type arteries are independent predictors of cardiovascular morbidity and mortality in hemodialysis patients.

Inclusion Criteria:

• end stage renal failure treated with chronic hemodialysis
• atrial fibrillation
• CHA2DS2-VASc Score ≥ 2
• ability to provide informed consent

Exclusion Criteria:

• known intestinal malabsorption or inability to take oral medication
• inability to stop co-medication that causes major interactions with rivaroxaban (e.g. ketoconazole, itraconazole, voriconazole, posaconazole, ritonavir, rifampicin, phenytoin, carbamazepine, phenobarbital or St John's wort)
• investigator's assessment that the subject's life expectancy is less than 1 year
• prosthetic mechanical heart valve
• contraindication for anticoagulation
• liver dysfunction Child-Pugh grade B-C
• pregnancy, breastfeeding, inadequate contraception
• incompliance with medication and scheduled investigations