Coronary artery calcification measured with electron-beam computerized tomography correlates poorly with coronary artery angiography in dialysis patients.
BACKGROUND
Coronary artery calcification measured by electron-beam computerized tomography (EBCT) correlates with plaque burden and vessel stenosis and is predictive of future cardiac events in the general population. Uremic vascular calcification is common and widespread, tends to be medial as well as intimal, and may not relate solely to atherosclerotic lesions. Despite this difference and in the absence of any direct evidence in uremic patients, it is generally implied that coronary artery calcification equates to occlusive atherosclerosis.


METHODS
We set out to compare the predictive value of coronary artery calcification assessed by EBCT with contemporaneous coronary angiography. We studied 18 patients with end-stage renal disease undergoing maintenance dialysis. Seventy-two coronary vessels were analyzed for angiographic evidence of stenotic disease and correlated with individual vessel calcification score.


RESULTS
There was no significant correlation between degree of vessel stenosis and calcification score for individual vessels in patients with a positive calcium scan. Specificity was 48% and the positive predictive value was 53%. However, a calcification score <20 strongly correlated with the absence of significant luminal narrowing, and a 0 calcification score had a negative predictive value of 87.5%.


CONCLUSIONS
Coronary artery calcification measured by EBCT is not an accurate marker of the degree of vessel stenosis in coronary artery disease in uremic patients and should not be used as a single screening test for atherosclerotic coronary disease.
Sharples
Edward J
EJ
Department of Renal Medicine and Transplantation, Royal London and St Bartholomew's Hospital, London, UK. edsharps@doctors.org.uk
Pereira
Divaka
D
Summers
Shaun
S
Cunningham
John
J
Rubens
Michael
M
Goldsmith
David
D
Yaqoob
Muhammad M
MM
D002114:Calcinosis / Q000150:complications / Q000000981:diagnostic imaging*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000150:complications* / Q000000981:diagnostic imaging*; D023921:Coronary Stenosis / Q000150:complications / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D006435:Renal Dialysis; D014057:Tomography, X-Ray Computed; D014511:Uremia / Q000150:complications