A. Jerkeman et al., Correlation between different intensities of anti-vitamin K treatment and coagulation parameters, THROMB RES, 98(6), 2000, pp. 467-471
In order to study the effect of different intensities of anti-vitamin K tre
atment on coagulation parameters, 23 patients with venous thromboembolism w
ere given, after the initial treatment period, warfarin at doses giving an
International Normalised Ratio of 1.3-2.0 for 4 weeks, and of 1.1-1.3 for a
nother 4 weeks. Blood samples were taken at the end of each of these period
s and 4 weeks after the end of warfarin treatment. The vitamin K-dependent
coagulation factors VII, IX, and X, as well as the inhibitor protein C and
its cofactor protein S, all showed a highly significant correlation with tr
eatment intensity. This was to some extent also true for the coagulation ac
tivation markers, prothrombin fragment 1 + 2 and thrombin-antithrombin comp
lex. Ratios of pro- and anticoagulant factors in some instances showed a de
crease at therapeutical (International Normalised Ratio) levels, and also s
ometimes with reduced warfarin treatment intensity. Taken together, our res
ults encourage further research addressing issues of varying treatment inte
nsity with warfarin and alternative methods for monitoring of anti-vitamin
K treatment. (C) 2000 Elsevier Science Ltd. All rights reserved.