The mean maximal prolongation of PT was 4.39-fold [ coefficient of variation ( CV ) 18.03 % ; range 3.39-6 .50 ] of the baseline value in groupA , compared with 1.88-fold ( CV 10.35 % ; range 1.53-2 .21 ) in groupB and 1.57-fold ( CV 9.98 % ; range 1.37-2 .09 ) in groupC .