Effects of fixed low-dose warfarin on hemostatic factors in continuous ambulatory peritoneal dialysis patients

Increased coagulation factors found in dialysis patients may explain in par t the high prevalence of thrombotic cardiovascular disease. Several studies showed low-dose warfarin is effective in decreasing coagulation factors an d preventing thrombosis without increasing the risk of bleeding. Tot evalua te the effects of fixed low-dose warfarin therapy on thrombogenesis in cont inuous ambulatory peritoneal dialysis (CAPD) patients, 76 CAPD patients wer e assigned randomly to treatment and disease control groups. The treatment group received 2 mg of warfarin daily for 12 months. International normaliz ed ratio (INR) of the prothrombin time and plasma levels of factor VII, D-d imer, von Willebrand factor (VWF), and plasminogen activator inhibitor-1 (P AI-1) were measured before and 3, 6, and 12 months after the start of medic ation. The same parameters were measured in 30 healthy volunteers at the be ginning of the study and in the disease control group during the study peri od. Of 76 patients, 60 completed the study. Deaths from atherosclerotic car diovascular disease (cerebral infarction or acute myocardial infarction) oc curred in 1 patient in the treatment group (n = 29) and 3 in the disease co ntrol group (n = 31), which was not statistically significant. No major ble eding occurred during the study period. With administration of warfarin, th ere was a small increase in INR in the treatment group. CAPD patients at ba seline had significantly higher plasma factor VII, D-dimer, VWF, and PAI-1 levels than normal controls. Warfarin therapy lowered plasma factor VII and D-dimer levels. No change was seen in vWF and PAI-1 levels. In the disease control group, these hemostatic factors showed no change during the study period. There was a negative correlation between serum albumin and INR in t he treatment group during the study period. Fixed low-dose warfarin was eff ective in partially reversing the thrombogenic coagulation profile in CAPD patients without a big increase in the risk of bleeding. (C) 2001 by the Na tional Kidney Foundation, Inc.