Coumarin use in dialysis patients with arterial fibrillation: yes, after individual risk stratification

arteries is observed. Administration of vitamin K antagonists to rodents induces vascular calcification and undercarboxylated MGP is detected at calcified sites within the aorta. In non-renal patients, vitamin K antagonists significantly increased both prevalence and extent of aortic valve and coronary calcifications. Vice versa, administration of vitamin K improved vascular properties like compliance, distensibility and intima–media thickness in postmenopausal women. Finally, coumarin use has been consistently identified as a risk factor for calciphylaxis in HD patients 8. Thus, increasing data show that the use of warfarin in HD patients accelerates cardiovascular calcification and is therefore a potent risk factor for morbidity and mortality 8. Whether dietary vitamin K supplementation in HD patients reduces the risk for cardiovascular calcification and mortality urgently needs to be tested. From the above, we conclude that there is at present limited evidence to support the use of coumarins in HD patients with AF. The potential benefits need to be balanced against the increase in major haemorrhage and the probable acceleration of vascular calcification and calciphylaxis risk. Until more data are available on this subject, it seems prudent to largely restrict oral anticoagulation to HD patients with AF who are categorized as ‘high risk’ based on the CHADS2 score. Conflict of interest statement. None declared.