Impact of flow-mediated dilatation and coronary calcification in providing complementary information on the severity of coronary artery disease.

BACKGROUND AND AIMS: Endothelial dysfunction and coronary artery calcification (CAC) may represent two distinct and separate processes in the development of coronary atherosclerosis. However, the interaction between these factors in determining the development of coronary artery disease (CAD) is uncertain.

METHODS: Brachial artery flow-mediated dilatation (FMD) was measured by high-resolution ultrasound before coronary angiography, in 156 patients undergoing coronary CT angiography on suspicion of CAD (M/F 100/56, age 67 ± 11yrs). CAC score was measured with the Agatston method.

RESULTS: The discriminative performance of FMD and CAC score in predicting the presence of type C lesion, multivessel disease, and high SYNTAX score (>22) was determined by ROC curve analysis. The optimal cutoff values for type C lesion were FMD ≤3.70% (AUC 0.663, p = 0.037) and log(CACscore+1)≥ 6.452 (AUC 0.735, p = 0.006). The combination of these cutoff values identified the lesion with the highest predictive accuracy of 82%. In addition, the optimal cutoff values for multivessel disease were FMD ≤5.40% (AUC 0.689, p = 0.001) and log(CACscore+1)≥ 5.914 (AUC 0.731, p = 0.001), while those for high SYNTAX score were FMD ≤4.10% (AUC 0.664, p = 0.020) and log(CACscore+1) ≥6.693 (AUC 0.817, p = 0.001). The combined measurement of each cutoff value identified multivessel disease and high SYNTAX score with predictive accuracy of 77% and 83%, respectively, which were significantly higher than each parameter alone, with the exception of the predictive accuracy of log(CACscore+1) for high SYNTAX score (p = 0.083).

CONCLUSIONS: Endothelial dysfunction and CAC may provide complementary information in predicting the extent and severity of coronary artery disease.