Combined aortic valve and coronary artery calcifications in lung cancer screening as predictors of death from cardiovascular disease

Objectives Smoking is a major risk factor for both cardiovascular disease (CVD) and lung cancer. Aortic valve calcification (AVC) and coronary artery calcification (CAC) are both due to atherosclerotic disease. We aim to investigate whether AVC on low-dose CT (LDCT) predicts death from CVD in smokers beyond that provided by CAC. Methods We reviewed a prospective cohort of 8618 smokers enrolled in LDCT screening for lung cancer in New York State between June 2000 and December 2005. As of December 2009, 169 of the 643 deaths were due to CVD; median follow-up time was 96.4 months. Visual AVC was assessed as being absent (AVC = 0) or present (AVC > 0). CAC ordinal scores of 0-12 were categorized into three validated prognostic categories (0, 1-3, and 4-12). Cox proportional hazards regression analysis was used to assess whether AVC > 0 increased the risk of CVD death, after adjustment for CAC categories and other risk factors. Results The prevalence of AVC significantly increased (p < 0.0001) with the increasing severity of the CAC categories; Pearson, Spearman, and Kendall's correlation coefficients showed a significant correlation between AVC and CAC withr = 0.29,rho = 0.32, and tau B = 0.28 (allpvalues < 0.0001), respectively. CAC and AVC were significant predictors of CVD death when considered alone using multivariable Cox regression analysis (adjusted HR of CAC = 1.57,p = 0.04; adjusted HR of AVC = 1.39,p = 0.045). When AVC > 0 and CAC >= 4, the hazard ratio was 2.35 (95%CI 1.57-3.50) compared with the reference group of AVC = 0 and CAC < 4, when adjusted for other risk factors. Conclusions The presence of AVC identified on LDCT is a significant predictor of future CVD death, particularly for those with ordinal CAC score >= 4.