Detection of Aortic Calcification during Vertebral Fracture Assessment (VFA) Compared to Digital Radiography

BACKGROUND: Cardiovascular disease is the most common cause of mortality among post-menopausal women. Our objective was to determine whether or not lateral spine images obtained on a bone densitometer to detect prevalent vertebral fracture can also accurately detect radiographic abdominal aortic calcification (AAC), an important risk factor for cardiovascular disease independent of clinical risk factors. METHODOLOGY/PRINCIPAL FINDINGS: One hundred seventy four postmenopausal women had bone densitometry, lateral spine densitometry imaging (called vertebral fracture assessment, or VFA), and lateral spine digital radiographs. Radiographs and VFA images were scored for AAC using a previously validated 24 point scale and a simplified, new 8 point scale (AAC-8). One hundred fifty six (90%) of the VFA images were evaluable for AAC. The non-parametric intraclass correlation coefficient between VFA and radiographic 24 point and AAC-8 readings, respectively, were 0.80 (95% C.I. 0.68-0.87) and 0.76 (95% C.I. 0.65-0.84). Areas under receiver operating characteristics (ROC) curves for VFA to detect those with a radiographic 24-point AAC score >or=5 were 0.86 (95% C.I. 0.77-0.94) using the 24 point scale and 0.84 (95% C.I. 0.76-0.92) using the AAC-8 scale. CONCLUSION/SIGNIFICANCE: VFA imaging intended to detect prevalent vertebral fracture can also detect radiographic AAC, an important cardiovascular disease risk factor. Since bone densitometry is recommended for all women age 65 and older, VFA imaging at the time of bone densitometry offers an opportunity to assess this risk factor in the post-menopausal female population at very little incremental time and expense.