Abstract 15721: Coronary Artery Calcium Scoring Effectively Stratifies Long-Term Mortality Risk in Smokers and Non-Smokers
Background: Cigarette smoking is a known risk factor for coronary heart disease (CHD). Studies have shown earlier onset and higher burden of coronary artery calcium (CAC) in smokers compared to non-smokers. However, little long-term follow-up data exists on the potential interaction between cigarette smoking and CAC for the prediction of important clinical outcomes.
Hypothesis: In the setting of cigarette smoking, CAC scoring should accurately predict clinical outcomes.
Methods: A total of 9,785 (mean age 53±10 years) consecutive asymptomatic individuals, free of known CHD, underwent computed tomography to estimate CAC for cardiovascular risk assessment. CHD risk factors were prospectively obtained by patient interview. Unadjusted and risk-factor adjusted Cox proportional hazard modeling was used to estimate time to all-cause mortality (mean follow-up=13.7 years) by CAC subsets.
Results: 3,833 patients (39.2%) were current smokers. Smokers were less likely than non-smokers to have a CAC score of 0 (42.7% vs 54.3%). For smokers and non-smokers, survival rates ranged from 60 to 94% and 73 to 97% by CAC subsets, respectively (see Figure, p<0.0001). Compared to CAC=0, adjusted hazard ratios for CAC scores of 1-10, 11-100, 101-399, 400-999, and ≤ 1000 were 1.8, 2.3, 2.7, 4.1, and 5.4 (p<0.0001) among smokers; and 1.4, 2.2, 4.1, 5.6, and 7.6 among non-smokers (interaction p<0.0001). Higher adjusted mortality was observed for CAC scores <400 among smokers as compared to non-smokers. The relative hazards for CAC scores of 400-999 (p=0.052) and ≥1,000 (p=0.14) were similar by smoking status.
Conclusion: CAC scoring effectively stratifies long-term all-cause mortality risk in both smokers and non-smokers. However, smokers are at substantially higher risk and excess mortality is noted for smoking patients with CAC scores <400. High risk CAC scores of 400 or higher carry a high mortality hazard for smokers and non-smokers.
Author Disclosures: T.A. Lebeis: None. P. Sandesara: None. J. Knapper: None. M.J. Blaha: None. D.S. Berman: None. A. Quyyumi: None. M.J. Budoff: None. J.K. Min: None. A.E. Giambrone: None. T.Q. Callister: None. L.J. Shaw: None.
- © 2014 by American Heart Association, Inc.