Section Editor: VK Bahl
Associate Editors: Gurpreet S Wander, Tiny Nair, Dinkar Bhasin
Percutaneous coronary intervention versus coronary artery bypass grafting in patients with three-vessel or left main coronary artery disease: 10-year follow-up of the multicentre randomised controlled SYNTAX trialARTICLE 1
Thuijs DJ, Kappetein AP, Serruys PW, Mohr FW, Morice MC, Mack MJ, et al. Percutaneous coronary intervention versus coronary artery bypass grafting in patients with three-vessel or left main coronary artery disease: 10-year follow-up of the multicentre randomised controlled SYNTAX trial.
Lancet. 2019;394:1325-34.
Abstract
Background: The SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and Cardiac Surgery) trial was a noninferiority trial that compared percutaneous coronary intervention (PCI) using first-generation paclitaxel-eluting stents with coronary artery bypass grafting (CABG) in patients with de-novo three-vessel and left main coronary artery disease, and reported results up to 5 years. We now report 10-year all-cause death results.
Methods: The SYNTAX Extended Survival (SYNTAXES) study is an investigator-driven extension of follow-up of a multicenter, randomized controlled trial done in 85 hospitals across 18 North American and European countries. Patients with de-novo three-vessel and left main coronary artery disease were randomly assigned (1:1) to the PCI group or CABG group. Patients with a history of PCI or CABG, acute myocardial infarction, or an indication for concomitant cardiac surgery were excluded. The primary endpoint of the SYNTAXES study was 10-year all-cause death, which was assessed according to the intention-to-treat principle. Prespecified subgroup analyses were performed according to the presence or absence of left main coronary artery disease and diabetes, and according to coronary complexity defined by core laboratory SYNTAX score tertiles. This study is registered with ClinicalTrials.gov, NCT03417050.
Findings: From March, 2005 to April, 2007, 1,800 patients were randomly assigned to the PCI (n = 903) or CABG (n = 897) group. Vital status information at 10 years was complete for 841 (93%) patients in the PCI group and 848 (95%) patients in the CABG group. At 10 years, 248 (28%) patients had died after PCI and 212 (24%) after CABG {hazard ratio 1.19 [95% confidence interval (CI) 0.99–1.43]; p = 0.066}. Among patients with three-vessel disease, 153 (28%) of 546 had died after PCI versus 114 (21%) of 549 after CABG [hazard ratio 1.42 (95% CI 1.11–1.81)], and among patients with left main coronary artery disease, 95 (27%) of 357 had died after PCI versus 98 (28%) of 348 after CABG [0.92 (0.69–1.22), pinteraction = 0.023]. There was no treatment-by-subgroup interaction with diabetes (pinteraction = 0.60) and no linear trend across SYNTAX score tertiles (ptrend = 0.20).
Interpretation: At 10 years, no significant difference existed in all-cause death between PCI using first-generation paclitaxel-eluting stents and CABG. However, CABG provided a significant survival benefit in patients with three-vessel disease, but not in patients with left main coronary artery disease.
Funding: German Foundation of Heart Research (SYNTAXES study, 5–10-year follow-up) and Boston Scientific Corporation (SYNTAX study, 0–5-year follow-up).
“As to diseases, make a habit of two things — to help, or at least, to do no harm.”
―Hippocrates
COMMENT
Despite the advanced knowledge and progress in the management of coronary artery disease (CAD), the role of percutaneous coronary intervention (PCI) on outcomes in patients with stable CAD continues to be debated. Several pivotal studies have shown that coronary artery bypass grafting (CABG) improves outcomes in patients with triple vessel disease and left main (LM) disease when compared to optimal medical therapy (OMT). The SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and Cardiac Surgery) trial was a pivotal study that compared PCI with CABG for patients with LM disease or triple-vessel disease (TVD).1 The study provided the SYNTAX score, based on anatomical characteristics of CAD, which is extensively used in clinical practice to decide the choice of revascularization, i.e., CABG or PCI, in decision-making regarding whether surgery or PCI will benefit the patients. PCI is preferred for patients with score ≤22, while CABG is preferred for patients with SYNTAX score ≥33. Patient with in between SYNTAX scores, PCI and CABG are comparable.
The SYNTAX Extended Survival study is a 10-year follow-up of the same cohort. The follow-up was complete in 94% of the patients but only survival data was available. There was no difference in all-cause mortality between the treatment modalities in the overall cohort. However, when patients were categorized on the basis of SYNTAX score, the survival advantage in patients with SYNTAX ≥33 was consistent. There was no difference in patients with LM disease irrespective of SYNTAX score. The presence or absence of diabetes mellitus (DM) did not influence outcomes. While a survival benefit with CABG was present in patients with TVD, subgroup analysis showed that this was significant only for patients with SYNTAX score >33.