Is abdominal aortic calcification score a cost-effective screening tool to predict atherosclerotic carotid plaque and cardiac valvular calcification in patients with end-stage renal disease?

Abdominal aortic calcification (AAC), cardiac valvular calcification (CVC), and atherosclerotic carotid plaque (CP) are known cardiovascular risk factors. The accuracy of the AAC score in predicting CP and CVC in patients with end-stage renal disease (ESRD) is assessed in this study. Twenty-two consecutive prevalent dialysis patients (group 1) and 26 consecutive nondialysis stage V chronic kidney disease patients (group 2) were assessed for their demographic and laboratory variables. Lateral radiograph of the lumbosacral spine was used to assess the AAC score. CP and CVC were assessed using carotid sonography and echocardiogram, respectively. Prevalence of AAC, CP, and CVC in groups 1 and 2 was, respectively, 72.7%, 81.8%, and 72.7% and 76.9%, 80.8%, and 57.7%. AAC was strongly associated with CP and CVC in both groups (P < 0.001). Tests of accuracy for the AAC score as a predictor of CP and CVC showed sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio of a positive test, and likelihood ratio of a negative test, respectively, in group 1: 83%, 75%, 93%, 50%, 3.32, and 0.23 and 85%, 77%, 87%, 70%, 4.5, and 0.29, and in group 2: 90%, 95%, 83%, 69%, 3.9, 0.41, and 82%, 91%, 77%, 71%, 4.1, and 0.21. Reproducibility of the AAC score among observers was acceptable. The AAC score can predict CP and CVC with moderate accuracy in ESRD patients. However, as our study was underpowered, the findings need validation in larger, adequately powered studies.