Accuracy of CT for selecting candidates for coronary artery bypass graft surgery: Combination with the SYNTAX score¹

Purpose: To investigate the diagnostic performance of coronary computed tomographic (CT) angiography for selecting candidates for coronary artery bypass graft (CABG) surgery according to the 2011 American College of Cardiology Foundation (ACCF) and American Heart Association (AHA) guidelines for CABG surgery and determine the added value of SYNTAX (Synergy between PCI with TAXUS and Cardiac Surgery) scoring for selecting CABG surgery candidates. Materials and Methods: Approval was obtained from the Institutional Review Board, and informed consent was waived for this retrospective study. A total of 399 patients (mean age, 63.8 years; 244 men and 155 women) who underwent both coronary CT angiography and invasive coronary angiography were included. Eligible criteria for CABG surgery were established on the basis of the 2011 ACCF/AHA guidelines. Results from coronary CT angiography and invasive coronary angiography were retrospectively reviewed, and SYNTAX scores were determined. The diagnostic performance of coronary CT angiography for selecting CABG surgery candidates was calculated with invasive coronary angiography as the reference method. The diagnostic performance of coronary CT angiography alone, the CT-based SYNTAX score, and the combined coronary CT angiography with CT-based SYNTAX score were assessed by using a combination of invasive coronary angiography and invasive coronary angiography-based SYNTAX scores as a reference method. Statistical analyses were performed by using the generalized estimating equation, independent t test, Mann-Whitney U test, Wilcoxon signed rank test, Fisher exact test, and χ² statistics. Results: The overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value of coronary CT angiography for selecting CABG surgery candidates were 96.5%, 96.5%, 88.3%, and 99.0%, respectively. When a combination of invasive coronary angiography with an invasive coronary angiography-based SYNTAX score was used as a standard reference, combined coronary CT angiography with a CT-based SYNTAX score had higher specificity and PPV (98.3% and 86.0%, respectively) than did coronary CT angiography alone (84.5% and 40.4%, respectively; P < .0001). Conclusion: Coronary CT angiography had diagnostic accuracy comparable to that of invasive coronary angiography for selecting CABG surgery candidates, and combining a CT-based SYNTAX score with coronary CT angiography can be a highly specific method for selecting CABG surgery candidates.