Abstract 19016: Angiographic Obstructive Disease Predicted by Calcium Scanning and XECG in Real-World Patients With Stable Chest Complaints
Introduction: Catheter (CAG) and computed angiography (CTA) are reliable means for exclusion of obstructive coronary artery disease (CAD), although costly with considerable exposure to radiation and contrast media.
Objective: To compare the accuracy of coronary calcium scanning (CCS) and exercise electrocardiography (XECG) as less expensive means to rule out obstructive CAD.
Methods: In a rapid-access chest pain clinic, 791 consecutive patients with stable complaints underwent both CTA and XECG. Using the Duke Clinical Score, pretest probability of CAD was classified into low (<30%), intermediate (30%–80%) or high (>80%). Referral to invasive CAG was clinically driven. Angiographic obstructive CAD was found in 153(21%) patients, defined as >50 % lumen diameter narrowing on CAG or, in the absence of CAG, >70 % lumen stenosis, >50 % left main coronary stenosis or >50% stenosis of 3 vessels on CTA. Absence of obstructive CAD was found in 547 patients, defined as < 50% lumen narrowing on CAG or CTA. In total 91 patients could not be classified by these criteria and were excluded.
Results: XECG non-diagnostic in 288 (41%) patients and CCS was not performed in 2 (0.3%) patients. Overall, angiographic CAD was significantly more likely after a positive XECG compared to a positive CCS result, LR + 3.58 (95% CI 2.71–4.73) vs. 1.90 (1.74–2.08). Absence of obstructive CAD was significantly more likely after a negative CCS compared with XECG, LR − 0.08 (0.04–.018) vs. 0.43 (0.33–0.57), most explicit in the intermediate risk group. Obstructive CAD was found in 6 (1%) patients with no calcium and 32 (8%) patients with a normal XECG. The diagnostic accuracy of XECG and CCS overall was 78% (74–82%) and 60% (56–63%).
Conclusion: CCS rules out obstructive CAD more reliably than XECG, particularly in low to intermediate risk groups and can be preformed in a substantially larger proportion of patients.
- © 2010 by American Heart Association, Inc.