Coronary artery calcification is related to coronary atherosclerosis in chronic renal disease patients: a study comparing EBCT-generated coronary artery calcium scores and coronary angiography.

BACKGROUND: Coronary artery calcification (CAC) measured by electron beam computed tomography (EBCT) correlates with plaque burden, vessel stenosis and is predictive of future cardiac events in the general population. Extensive CAC has been described recently in dialysis cohorts. For the first time we studied the relationship between CAC and coronary angiographic findings in patients with chronic renal failure, on dialysis and after renal transplantation. METHODS: We studied 46 patients who all had an EBCT-derived Agatston coronary calcium score and a diagnostic coronary angiogram within a 12-month period. The mean age was 55.7+/-13.2 (SD) years (range 29-80). The mean duration of dialysis was 54.4 months (range 1-372). RESULTS: The mean CAC was 2370+/-352.8. The mean CAC in patients with an abnormal coronary angiogram (n = 35) was 2869.6+/-417.9, while that in patients with a normal coronary angiogram (n = 11) was 559.4+/-255.1 (P = 0.001 for the inter-mean comparison). Total CAC correlated with the number of diseased vessels (P = 0.0001) and with severity of atherosclerosis in all the vessels (P = 0.0001). The individual coronary artery calcification score correlated well with the severity of atherosclerotic coronary disease (P<0.0001 for all) in the left anterior descending, right coronary and circumflex arteries. Running a multivariate regression analysis for atherosclerosis burden, we found that the only predictor was CAC (r = 0.34, P = 0.0001). CONCLUSION: CAC is common and more severe in patients with chronic kidney disease. Although in chronic kidney disease patients CAC can occur in the absence of occlusive coronary atherosclerosis, our data suggest that, as in the general population, CAC in chronic kidney disease patients is associated with obstructive atherosclerosis and may therefore be associated with a worse outcome.