D‐dimer levels in maintenance hemodialysis patients: High prevalence of positive values also in the group without predisposing diseases

We aimed to estimate the prevalence of elevated D‐dimer levels in all chronic hemodialysis patients and those without additional disease, and to identify factors associated with increased D‐dimer. In 167 chronic hemodialysis patients from our center, D‐dimer was measured before dialysis. The effects of age, C‐reactive protein (CRP), recent acute illness, vascular access, anticoagulation type, dialysis vintage, and chronic diseases, considered to predispose for increased D‐dimer levels, were analyzed. The median D‐dimer in the whole group was 966 (inter‐quartile range IQR] 524–1947) μg/L and was positive (>500 μg/L) in 75% of cases. D‐dimer was positive in 91% of patients with acute illness, 76% of those with predisposing chronic diseases, but was still positive in 52% of patients without additional disease (i.e., acute illness or predisposing chronic diseases) – median D‐dimer was 538.5 (IQR 359–966) μg/L. D‐dimer was correlated to patients' age, but not dialysis vintage. In univariate analysis, the D‐dimer levels were significantly higher in patients with atrial fibrillation, ischemic heart disease, recent acute illness, increased CRP, dialyzed over a catheter, and on citrate anticoagulation. Multivariate logistic regression showed that only age >65 years (odds ratio OR] 2.93), catheter (OR 4.86), and positive CRP (OR 4.07) were independently associated with positive D‐dimer at 500 μg/L cut‐off, while the significance of age disappeared at 2000 μg/L cut‐off. To conclude, the high prevalence of positive D‐dimer values even in hemodialysis patients without additional disease limits the use of D‐dimer for exclusion of thromboembolic diseases in hemodialysis patients.