Association of risk stratification score with dialysis vascular access stenosis

Clinical monitoring is the recommended standard for identifying dialysis access dysfunction; however, clinical monitoring requires skill and training, which is challenging for understaffed clinics and overburdened healthcare personnel. A vascular access risk stratification score was recently proposed to assist in detecting dialysis access dysfunction.

Our objective was to evaluate the utility of using vascular access risk scores to assess venous stenosis in hemodialysis vascular accesses.

We prospectively enrolled adult patients who were receiving hemodialysis through an arteriovenous access and who had a risk score ⩽3 (low-risk) or ⩾8 (high-risk). We compared the occurrence of access stenosis (>50% on ultrasonography or angiography) between low-risk and high-risk groups and assessed clinical monitoring results for each group.

Of the 38 patients analyzed (18 low-risk; 20 high-risk), 16 (42%) had significant stenosis. Clinical monitoring results were positive in 39% of the low-risk and 60% of the high-risk group (p = 0.19). The high-risk group had significantly higher occurrence of stenosis than the low-risk group (65% vs 17%; p = 0.003). Sensitivity and specificity of a high score for identifying stenosis were 81% and 68%, respectively. The positive predictive value of a high-risk score was 65%, and the negative predictive value was 80%. Only 11 (58%) of 19 subjects with positive clinical monitoring had significant stenosis. In a multivariable model, the high-risk group had seven-fold higher odds of stenosis than the low-risk group (aOR = 7.38; 95% CI, 1.44-37.82; p = 0.02). Positive clinical monitoring results and previous stenotic history were not associated with stenosis. Every unit increase in the score was associated with 34% higher odds of stenosis (aOR = 1.34; 95% CI, 1.05-1.70; p = 0.02).

A calculated risk score may help predict the development of hemodialysis vascular access stenosis and may provide a simple and reliable objective measure for risk stratification.