Higher D-dimer levels were associated with increased frequencies of stroke or systemic embolism ( hazard ratio [ HR ] [ Q4 vs. Q1 ] 1.72 , 95 % confidence interval [ CI ] 1.14-2 .59 , P = 0.003 ) , death ( HR [ Q4 vs. Q1 ] 4.04 , 95 % CI3.06-5 .33 ) and major bleeding ( HR [ Q4 vs. Q1 ] 2.47 , 95 % CI1.77-3 .45 , P < 0.0001 ) in the no-VKA group .