New indices to classify location, severity and progression of calcific lesions in the abdominal aorta: a 25-year follow-up study

The purpose of the present study was to assess the location, severity and progression of radiopaque lumbar aortic calcifications and to evaluate the utility of summary scores of lumbar calcification in a population-based cohort. Lateral lumbar films, obtained in 617 Framingham heart study participants, were analysed for the presence of abdominal aortic wall calcification in the region corresponding to the first through fourth lumbar vertebrae. The severity of the anterior and posterior aortic calcification were graded individually on a 0-3 scale for each lumbar segment and the results were summarized to develop four different composite scores: (1) affected segments score (range 0-4); (2) anterior and posterior affected score (range 0-8); and (3) antero-posterior severity score (range 0-24). The prevalence of aortic calcification was 37% in men and 27% in women at baseline and 86% in both genders at the follow-up exam 25 years later. During the follow-up interval, the mean of the affected segments score increased from 0.7 in men (0.5 in women) to 2.7 (2.8 in women), the mean of the anterior and posterior affected score from 1.2 (0.8 in women) (P = 0.012 for difference between genders) and the mean of the antero-posterior severity score increased from 1.5 (1.3 in women) to 9.3 (10.3 in women). The antero-posterior severity score offered a slight advantage over other composite scores and had the highest inter-rater intra-class correlations. In summary, lumbar aortic calcification can be graded and composite summary scores are reproducible. This technique appears to provide a simple, low cost assessment of subclinical vascular disease.