Abstract 16304: Aortic Valve Calcification on Cardiac Computed Tomography and All Cause Mortality
Background: Aortic sclerosis histologically resembles atherosclerosis and is characterized by progressive calcification of the valve leaflets. Aortic valve calcium (AVC) is routinely observed on CT scans for coronary artery calcium (CAC) scoring. While CAC is an established predictor of cardiovascular events, there is limited evidence for an independent predictive value for AVC.
Methods: We studied a cohort of 8,401 asymptomatic individuals (mean age 53±10 years, 69% men) undergoing computed tomography (CT) for assessment of subclinical atherosclerosis. Patients were followed for a median of 5 years (range 1–7 years) for the occurrence of mortality from any cause. Multivariable Cox regression models were developed to predict all-cause mortality based on the presence of AVC.
Results: A total of 517 (6%) patients had AVC on CT. During follow-up there were 124 deaths (1.5%), with overall survival 96.1% and 98.7% for those with and without AVC, respectively (HR 3.39, 95% CI 2.09 - 5.49). Overall, the lowest event rate was observed amongst individuals with no AVC and CAC<100 (1.6 deaths/1,000 person years), while the highest rate was among those with AVC and CAC≥100 (13.0 deaths/1,000 person years). After adjustment for age, gender, hypertension, dyslipidemia, diabetes mellitus, smoking, and family history of premature CHD, increasing AVC remained a significant predictor of mortality (HR 1.82, 95% CI 1.11 - 2.98). Importantly, increased risk with AVC remained robust (HR 1.66, 95% CI 1.01 - 2.72) when CAC was added to the multivariate analysis. Likelihood ratio chi-square statistics demonstrated that AVC contributed significantly to risk prediction in models adjusted for traditional risk factors (5.03, p=0.03) as well as risk factors + presence of CAC (3.58, p=0.05).
Conclusions: AVC is associated with increased all-cause mortality independent of traditional risk factors and presence of CAC. AVC should be considered during routine interpretation of cardiac CT scans.
- © 2010 by American Heart Association, Inc.