Carotid doppler ultrasonography as a surrogate for coronary CT angiography to exclude subclinical coronary atherosclerosis in asymptomatic patients with a negative coronary calcium score

Purpose: To evaluate the diagnostic accuracy of carotid Doppler ultrasonography (CDU) to predict the presence of subclinical coronary atherosclerosis in asymptomatic subjects with a zero coronary calcium score. Methods: Retrospective study of CDU and coronary CT angiography (CTA) findings in 118 asymptomatic subjects with a zero calcium score. CDU was considered abnormal when carotid intima‐media thickness was >75 percentile or was ≥ 1 mm, or in presence of carotid plaque(s). We analyzed the diagnostic accuracy of CDU to predict the presence of non‐calcified coronary plaque in comparison with coronary CTA. Results: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of abnormal CDU to identify the presence of non‐calcified coronary plaque on coronary CTA were 82.4% [(14/17); 95% confidence interval (CI), 56.6%‐96.2%], 53.5% [(54/101); 95% CI, 43.3%‐63.5%], 23.0% [(14/61); 95% CI, 13.1%‐35.6%], and 94.7% [(54/57); 95% CI, 85.4%‐98.9%], respectively. Conclusions: Although CDU has a low PPV for identifying the presence of non‐calcified plaque on coronary CTA, its NPV is high to exclude subclinical coronary atherosclerosis in asymptomatic subjects with a zero calcium score. © Inc. J Clin Ultrasound, 2013