SYNTAX and CABG after two years

Posted on December 23, 2010 - 12:14am

A new study, published in the Januari, 2011 issue of the Journal of Thoracic and Cardiovascular Surgery, reviewed 2-year follow-up outcome data of  1468 CABG patients from the SYNTAX trial.

Coronary artery bypass grafting (CABG), rather than percutaneous coronary intervention (PCI) continues to be the recommended primary revascularization strategy for patients with stable angina who have coronary triple vessel disease (3-VD) or left main (LM) disease.

In SYNTAX, using an “all comers” design, patients with de novo 3-VD and/or LM disease were screened for study suitability by a local Heart Team that was composed of an interventional cardiologist, a cardiac surgeon, and the study coordinator. If the consensus decision was that comparably complete revascularization could be achieved by either PCI or CABG therapy, the patient was randomized to one of the treatment options. A total of 903 patients were assigned to PCI using TAXUS Express paclitaxel-eluting stents (Boston Scientific, Natick, Mass) and 897 patients were assigned to CABG surgery.

The primary  study end point for the randomized cohort was the overall MACCE rate at 12 months’ follow-up, but patients were followed up to 5 years after allocation. The SYNTAX study also included two nested registries, one for PCI-ineligible patients (CABG registry) and one for CABG-ineligible patients (PCI registry). A total of 1079 patients were allocated to the CABG registry. Reasons not to randomize these patients were predominantly complex coronary anatomy (70.9%) and potentially untreatable coronary chronic total occlusion (22.0%). All patients were subdivided in three groups of escalating SYNTAX Score Risks. The raw SYNTAX score was predictive of outcomes in patients who underwent PCI but not for CABG.

Ultimately, a total of 1541 SYNTAX CABG patients were assigned to 5 years’ follow-up and analyzed for the current study (897 randomized and 644 registry patients). Overall 2-year follow-up was available on 1468 CABG patients, corresponding to a follow-up rate of 95.3%. 

The results are summarized in the following graphs:

Overall 2-year MACCE rate and MACCE components of the entire SYNTAX CABG study population (n = 1468), divided by incidence during the first and second year after allocation. MACCE, Major adverse cardiac and cerebrovascular event; MI, myocardial infarction; CVA, cerebrovascular event; RR, repeat revascularization; GO, symptomatic graft occlusion. Safety end point was defined as combined end point of Death, MI and CVA.


MACCE in CABG patients increased not with high raw SYNTAX scores. Kaplan–Meier curves for 2-year MACCE in CABG divided by raw SYNTAX score. Patients with low (0–22; 15.6%), intermediate (23–32; 14.3%),and high (≥33; 15.4%) SYNTAX scores have similar 2-year MACCE rates. Numbers in the figure are cumulative event rates ± 1.5 standard error. MACCE, Major adverse cardiac and cerebrovascular event.

Two-year freedom from MACCE of SYNTAX coronary artery bypass patients comparing complete and incomplete revascularization. MACCE, Major adverse cardiac and cerebrovascular event.


The purpose of this study iwas to describe the current status of CABG based on the SYNTAX CABG cohort and to identify risk factors using SYNTAX severity score terciles.The Outcome data showed very low early and follow‑up mortality rates. While the SYNTAX Score is a unique tool to score complexity of coronary artery disease, this grouping showed  no outcome difference in mortality (1.0%), nor long-term survival in CABG, as opposed to PCI where the SYNTAX severity score showed a strong correlation.

(From: Complex coronary anatomy in coronary artery bypass graft surgery: Impact of complex coronary anatomy in modern bypass surgery? Lessons learned from the SYNTAX trial after two years Mohr et al. J Thorac Cardiovasc Surg.2011; 141: 130-140)