Lateral lumbar radiography to assess abdominal aortic calcification in haemodialysis patients.

Aim: To assess the prevalence of abdominal aortic calcification (ACC) using simple radiological imaging in dialysis patients. Background(s): Vascular calcification is highly prevalent in patients with chronic kidney disease on dialysis. Plain X-rays can detect AAC, although AAC is less well documented in anatomical distribution and severity compared to coronary calcification. This study is an analysis of AAC in prevalent Australian haemodialysis (HD) patients. Method(s): Lateral lumbar X-ray of the abdominal aorta was used to determine the overall AAC score, which is related to the severity of calcific deposits at lumbar vertebral segments L1 to L4. Semi-quantitative measurement, using a validated 24-point scale, was determined by two radiologists on HD patients from 7 satellite dialysis centres. Result(s): A lateral lumbar X-ray was obtained in 134 patients. Patients were aged 67 +/- 12 years, 67% were male, 36% diabetic with mean duration of HD 54 +/- 48 months. Calcification (AAC score >= 1) was present in 94.4% of patients. The mean AAC score was 11.0 +/- 6.4 (median 12). Independent predictors for the presence and severity of calcification were age (P < 0.0001) and duration of dialysis (P = 0.003). There was no significant association between AAC and time-averaged serum markers of mineral metabolism, lipid status, CRP levels or the presence of diabetes. Vertebral fractures were noted on 7% of X-rays. Conclusion(s): AAC detected by lateral lumbar X-ray is associated with increasing age and duration of HD. This semi-quantitative method of determining vascular calcification is more widely available and less expensive than current procedures and could form part of cardiovascular risk stratification.