Association of Level and Increase in D‐Dimer With All‐Cause Death and Poor Functional Outcome After Ischemic Stroke or Transient Ischemic Attack

BACKGROUND: D‐dimer is involved in poor outcomes of stroke as a coagulation biomarker. We aimed to investigate the associations of the level and increase in D‐dimer between baseline and 90 days with all‐cause death or poor functional outcome in patients after ischemic stroke or transient ischemic attack. METHODS AND RESULTS: We collected data from the CNSRIII (Third China National Stroke Registry) study. The present substudy included 10 518 patients within 7 days (baseline) of ischemic stroke or transient ischemic attack and 6268 patients at 90 days. Poor functional outcome at 1 year was assessed on the basis of the modified Rankin Scale (≥3). Multivariable Cox regression or logistic regression was used to assess the association of D‐dimer levels with all‐cause death or poor functional outcome. D‐dimer levels at 90 days were lower than those at baseline (1.4 µg/mL versus 1.7 µg/mL; P<0.001). Higher baseline D‐dimer level was associated with all‐cause death (adjusted hazard ratio [HR], 1.77; 95% CI, 1.25–2.52; P=0.001) and poor functional outcome (adjusted odds ratio [OR], 1.49; 95% CI, 1.23–1.80; P<0.001) during 1‐year follow‐up. Higher D‐dimer level at 90 days was also associated with poor outcomes independently. Furthermore, an increase in D‐dimer levels between baseline and 90 days was associated with all‐cause death (since 90 days to 1 year after index event) (adjusted HR, 1.99; 95% CI, 1.12–3.53; P=0.019) but not with poor functional outcome (adjusted OR, 1.08; 95% CI, 0.82–1.41). CONCLUSIONS: Our study shows that high level and an increase in D‐dimer between baseline and 90 days are associated with poor outcomes in patients after ischemic stroke or transient ischemic attack.