Correlation of simple imaging tests and coronary artery calcium measured by computed tomography in hemodialysis patients

Vascular calcification is associated with an adverse prognosis in end-stage renal disease. It can be accurately quantitated with computed tomography but simple in-office techniques may provide equally useful information. Accordingly we compared the results obtained with simple non-invasive techniques with those obtained using electron beam tomography (EBT) for coronary artery calcium scoring (CACS) in 140 prevalent hemodialysis patients. All patients underwent EBT imaging, a lateral X-ray of the lumbar abdominal aorta, an echocardiogram, and measurement of pulse pressure (PP). Calcification of the abdominal aorta was semiquantitatively estimated with a score (Xr-score) of 0–24 divided into tertiles, echocardiograms were graded as 0–2 for absence or presence of calcification of the mitral and aortic valve and PP was divided in quartiles. The CACS was elevated (mean 910±1657, median 220). The sensitivity and specificity for CACS≥100 was 53 and 70%, for calcification of either valve and 67 and 91%, respectively, for Xr-score ≥7. The area under the curve for CACS≥100 associated with valve calcification and Xr-score was 0.62 and 0.78, respectively. The likelihood ratio (95% confidence interval) of CACS≥100 was 1.79 (1.09, 2.96) for calcification of either valve and 7.50 (2.89, 19.5) for participants with an Xr-score ≥7. In contrast, no association was present between PP and CACS. In conclusion, simple measures of cardiovascular calcification showed a very good correlation with more sophisticated measurements obtained with EBT. These methodologies may prove very useful for in-office imaging to guide further therapeutic choices in hemodialysis patients.