The association between abdominal aortic calcification on lateral spine images captured during bone mineral density testing and incident aortic valve stenosis
W A Courtney, M Sim, C J Schultz, C Smith, R L Prince, J T Schousboe, W H Lim, K Zhu, N Bondonno, G S Hillis, J Hodgson, J R LewisAbstract
Introduction
Calcific aortic valve stenosis (CAS) is the third most common cardiac condition in high-income countries, and the burden of this disease is increasing with the ageing populations of high-income countries. But CAS remains significantly underdiagnosed and identifying individuals at risk for this valvulopathy is a healthcare imperative. The target cohort for population-based osteoporosis screening are elderly, more likely to lead sedentary lives and to smoke. They are therefore at increased risk for CAS.[1]
Purpose
The current study aims to assess if there is an association between abdominal aortic calcification (AAC) and incident CAS.
Methods
We undertook a prospective study of 1,046 women ≥70 years of age who had lateral spine imaging taken at the time of dual energy X-ray absorptiometry (DXA) bone density testing. These images were analysed by an experienced investigator using an established technique to assess the extent of AAC.[2, 3] The severity of AAC was described using a 24-point Kaupilla scale score (AAC-24), and classified using previously established categories of low (AAC-24 of 0 or 1) vs moderate-or-severe (AAC-24 ≥2).[2] Incident CAS over 14.5 years of follow up was identified by linked hospital data and death records.
Results
There were 578 women (55%) with moderate-to-severe AAC. Over 14.5 years, 34 women (3.3%) experienced incident CAS, and 31 of these patients suffered subsequent hospitalisation or death from any cause after their diagnosis of CAS. The presence of moderate-or-severe AAC was associated with a 2.5-to-3-fold increase in the relative hazard of incident CAS in the adjusted analysis (hazard ratio [HR], 2.81; 95% CI, 1.27-6.20, p = 0.011), compared to women with low AAC.
Conclusions
Older women with higher levels of AAC, identified using DXA lateral spine images, are at substantially higher risk of incident CAS. Given the widespread use of DXA machines in women over the age of 65 years, the routine evaluation of AAC at the time of bone density testing may provide a valuable risk stratification mechanism for incident CAS.