Abstract 16500: Adding Coronary Computed Tomography Angiography on the Patients Undergoing Invasive Coronary Angiography Improves the Prediction of the Coronary Artery Events
Introduction: Invasive coronary angiography (ICA) has been reported to have limitations to predict future coronary events by serial ICA examination, since acute coronary syndrome (ACS) could occur from not only severely but also mildly to moderately obstructive lesions. On the other hand, previously we revealed that the patients demonstrating high risk plaque (HRP) including positive vessel remodeling and/or low-attenuation on coronary computed tomography angiography (CTA) were at a high risk of ACS developing.
Hypothesis: We assessed the hypothesis that detecting HRPs by CTA in patients undergoing ICA improves the prediction of coronary events defined as ACS and late revascularization.
Methods and Results: We studied 535 patients undergoing both ICA and CTA within 3 months of each other. After excluding previous or scheduled PCI segments, and chronic total occlusion lesions, we divided all coronary artery segments into 4 groups by ICA: Group A (< 25% stenosis), Group B (25 to 49%), Group C (50 to 74%), and Group D (≥ 75%), and into 2 groups by CTA: Group X (HRP), and Group Y (no HRP). Coronary events occurred in 42 patients (48 lesions) for a median follow-up of 23 months. The event rates were extremely low in segments of Group A; 0.2%, compared to of other groups (2.0%, 3.4%, and 3.0% of plaques in Group B, C, and D, respectively), and much higher in those of Group X than of Group Y (12.8% vs. 0.42%). The multivariate cox hazard analysis revealed that previous ACS, residual stenosis ≥ 25% on ICA, and the presence of HRP on CTA were significant predictors of events (HR: 2.11; 95% CI: 1.11 to 4.21; p = 0.0214, HR: 5.13; 95% CI: 1.58 to 31.5; p = 0.0035, and HR: 4.21; 95% CI: 2.29 to 7.78; p < 0.0001, respectively). Adding the presence of HRP to a model including age, gender, hypertension, dyslipidemia, diabetes, current smoking, previous ACS, and residual stenosis ≥ 25% improved the prediction of events with increasing the net reclassification improvement (52.8%, p=0.0005).
Conclusions: Assessing coronary plaque characteristics by CTA improves the prediction of coronary events in patients undergoing ICA. Furthermore, detecting high risk plaque by CTA is possible to be useful for secondary prevention in previous ACS patients with mildly to moderately obstructive residual lesions.
- © 2013 by American Heart Association, Inc.