Abstract 9801: Patient- and Vessel-based SYNTAX Scores by Coronary Computed Tomographic Angiography: A Direct Comparison to Invasive Coronary Angiography

Abstract

Introduction: The SYNTAX score is commonly used to assess the complexity of coronary artery disease (CAD) by invasive coronary angiography (ICA), and to classify patients at risk for major adverse cardiovascular events following percutaneous coronary intervention. To date, whether the SYNTAX score can be reliably determined from noninvasive coronary CT angiography (CCTA) has not been fully explored.

Hypothesis: To determine the correlation between global and vessel-specific SYNTAX scores derived from CCTA and ICA.

Methods: We evaluated 94 consecutive patients (mean age - 66 years, 66% male gender) with and without known CAD, who underwent CCTA and subsequent ICA within 5 days, due to obstructive (>50% stenosis) single-, double-, or triple-vessel CAD. Patients with prior coronary bypass surgery were excluded. Per-patient and per-vessel SYNTAX scores were calculated from CCTA and ICA in blinded fashion by independent and experienced readers. CCTA SYNTAX scores incorporated identical variables as ICA SYNTAX scores. Paired student’s t-test and Spearman’s rank test were employed to determine the relation between CCTA and ICA scores, as well as Bland Altman analysis for agreement.

Results: On a per-patient basis, obstructive 1-vessel disease (VD), 2-VD and 3-VD was found in 41 (44%), 37 (39%) and 16 (17%) patients, respectively. Left main (LM), left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) obstructive disease was identified in 7 (7%), 69 (73%), 43 (46%) and 47 (50%) patients, respectively. Mean per-patient CCTA and ICA SYNTAX scores were similar (11.2 vs. 11.7, respectively, p=0.07) with excellent correlation and agreement (table). Similar results were observed for per-vessel measures (table).

Conclusion: Per-patient and per-vessel SYNTAX scores derived from CCTA demonstrate high correlation and agreement to ICA SYNTAX scores. Evaluation of CCTA SYNTAX scores for prediction of pre-ICA risk for MACE now appears warranted.