Predictors of Severe or Moderate Coronary Artery Disease in Asymptomatic Individuals with Extremely Low Coronary Calcium Scores

PURPOSE: To evaluate predictors of severe or moderate coronary artery disease (CAD) in individuals with zero or very low (<10) coronary artery calcium (CAC) scores. MATERIALS AND METHODS: The 1175 asymptomatic persons with zero or very low (<10) CAC scores were analyzed for CAD stenosis using coronary computed tomography angiography. Moderate and severe CADs were defined as having more than 50% and more than 70% stenosis in any of the major coronary arteries, respectively. Age, gender, body mass index, hypertension, type II diabetes, dyslipidemia, lipid profile, creatinine, and smoking status were evaluated as predictors for moderate and severe CAD. RESULTS: In the study population, moderate and severe CADs were found in 7.5% and 3.3%, respectively. Among evaluated risk factors, age [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.02−1.07, p<0.001], current smoking status (OR 3.12, 95% CI 1.82−5.34, p<0.001), and CAC 1−9 (OR 1.80, 95% CI 1.08−3.00, p=0.024) were significantly associated with moderate CAD. Meanwhile, age (OR 1.05, 95% CI 1.02−1.08, p=0.003), low high density lipoprotein (HDL) (OR 0.96, 95% CI 0.93−0.99, p=0.003), and current smoking status (OR 2.34, 95% CI 1.14−5.30, p=0.022) were found to be significantly associated with severe CAD. Improvement of discrimination power for predicting severe CAD was observed when smoking and HDL cholesterol were serially added into the age model. CONCLUSION: Smoking showed significant correlations with moderate or severe CAD, and low HDL cholesterol also proved to be a predictor of severe CAD in asymptomatic individuals with extremely low CAC scores.