CABG SYNTAX for Predicting Post-PCI Events in CAD Patients with Previous CABG
- The coronary artery bypass (CABG) SYNTAX score (CSS) was studied to determine its prognostic significance in patients who have previously received CABG and who were undergoing PCI as a secondary revascularization strategy.
- The SYNTAX score is an objective scoring system commonly used to identify the optimal revascularization strategy for patients with coronary artery disease (CAD).
- A high post-PCI CSS was shown to be a significant predictor for the primary endpoints, and the correlation of a high CSS score post-PCI with worse clinical outcomes was consistently noted in this study.
- This study shows there is prognostic applicability of CSS in patients receiving PCI who previously underwent CABG therapy.
Coronary artery bypass grafting (CABG) as well as percutaneous coronary intervention (PCI) are two of the most widely used modalities for coronary revascularization in patients with coronary artery disease (CAD). Late graft failures of saphenous vein grafts in CABG and deterioration of the native coronary arteries, however, can increase the risk for long-term ischemia.
For these patients who have previously received CABG, PCI is often recommended for repeat coronary revascularization.1 Despite increased PCI procedures, it can be challenging to determine the most ideal revascularization strategy for this population group.
Researchers Miyagi et al in a study published in Circulation: Cardiovascular Interventions retrospectively examined the prognostic capability of the Synergy Between Percutaneous Coronary Intervention with Taxus (SYNTAX) score (SS) in patients (n=434) who have previously received CABG for coronary revascularization.2
The SYNTAX score is an objective scoring system based on coronary angiography and is commonly used to identify the optimal revascularization strategy for patients with CAD.
The CABG SS (CSS) evaluates the native coronary atherosclerotic and myocardial ischemic burden as well as coronary revascularization incompleteness following CABG. Specifically, researchers wanted to see what impact, if any, the CSS had on stratifying or predicting risk in CAD patients prior to and after PCI.
In this study, the CSS calculated the residual coronary lesions before and after PCI (baseline CSS (bCSS) and post-PCI CSS, respectively). Patient follow-up data was obtained via mailed questionnaires, telephone interviews, and outpatient documentation from the hospital’s database.
Primary Endpoint: major adverse cardiovascular events (MACE), cardiac death, cardiovascular death, and all-cause mortality.
A small number of patients (n=33, 7.6%) underwent PCI due to early graft failure following CABG. Based on the median post-PCI CSS, patients were divided into the following 2 groups:
Low-score (≤23, n=217)
High-score (>23, n=217)
Patients with a high CSS score were significantly more likely to have chronic kidney disease (CKD), peripheral artery disease, 3-vessel disease, chronic total occlusion, acute coronary syndrome, left main disease, and previous heart failure when compared with the low-score group.
A high post-PCI CSS was shown to be a significant predictor for the primary endpoints, according to a univariable Cox regression analysis. The incidence of the endpoints for the low- and high-score groups were as follows:
- MACE: 13.8% vs 28.6%, respectively
- Cardiac death: 6.2% vs 16.7%, respectively
- All-cause mortality: 18.8% vs 26.0%, respectively
PCI efficacy in this study was fairly low, possibly because of the population group studied had a higher rate of comorbidities and advanced atherosclerosis.
The correlation of a high CSS score post-PCI with worse clinical outcomes was consistently noted in this study, indicating the prognostic applicability of CSS in patients who have previously received CABG therapy. Employing the CSS prior to secondary revascularization may be an added step to ensuring the most optimal revascularization strategy for these patients.
- Escaned J. Secondary revascularization after CABG surgery. Nat Rev Cardiol. 2012;9(9):540-549.
- Miyagi T, Asaumi Y, Nishimura K, et al. Validation of the Coronary Artery Bypass Graft SYNTAX Score (Synergy Between Percutaneous Coronary Intervention With Taxus) as a Prognostic Marker for Patients With Previous Coronary Artery Bypass Graft Surgery After Percutaneous Coronary Intervention. Circ Cardiovasc Interv. 2016;9(9). pii: e003459.