SYNTAXES: CABG preferable to PCI in multivessel disease

The mortality rate for patients who undergo percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for de-novo three-vessel disease or left main coronary artery disease (CAD) is comparable at 10 years. However, CABG may be preferable for those with three-vessel disease, according to the SYNTAX Extended Survival (SYNTAXES) study, a 10-year follow-up of the SYNTAX* trial.

While there was no treatment-related difference in all-cause death for patients with left main disease, CABG versus PCI provided a significant survival benefit for patients with three-vessel disease, said study lead author Dr Daniel Thuijs from Erasmus University Medical Centre, Rotterdam, the Netherlands.

“These findings can aid decision making for patients with CAD who require PCI or CABG,” said Thuijs and co-authors.

Participants in the multicentre trial were 1,800 adults with de-novo three-vessel disease or left main CAD who were randomized to undergo PCI with first-generation paclitaxel-eluting stents (n=903, mean age 65.2 years, 24 percent female) or CABG (n=897, mean age 65 years, 21 percent female). Information for 10-year analysis was available for 841 and 848 patients, respectively. Patients were followed up for a median 11.2 years.

Overall, all-cause death rate at 10 years was comparable between patients who underwent PCI and CABG (27.0 percent vs 23.5 percent, hazard ratio [HR], 1.17, 95 percent confidence interval [CI], 0.97–1.41; p=0.092). [ESC 2019, FP number 4197; Lancet 2019;doi:10.1016/S0140-6736(19)31997-X]

Among patients with three-vessel disease, 10-year all-cause mortality rates were higher among those who underwent PCI compared with CABG (27.7 percent vs 20.6 percent, HR, 1.41, 95 percent CI, 1.10–1.80; p=0.006). Conversely, no between-group difference in mortality rate was noted between patients with left main CAD (isolated or in combination with one- to three-vessel CAD) who underwent PCI and CABG (26.1 percent vs 26.7 percent, HR, 0.90, 95 percent CI, 0.68–1.20; p=0.47).

This result was comparable to the findings at 5 years, with a significant survival benefit with CABG over PCI in patients with three-vessel disease (mortality rate, 9.2 percent vs 14.6 percent; p=0.006) and no between-group difference in patients with left main disease (14.6 percent vs 12.8 percent; p=0.53).

In subgroup analyses in patients with and without diabetes**, mortality rate did not significantly differ between those who underwent PCI and CABG (34.2 percent vs 32.1 percent, HR, 1.10; p=0.56 [diabetes] and 24.6 percent vs 20.7 percent, HR, 1.20; p=0.11 [no diabetes]; p_interaction=0.66).

There was an increasing trend of mortality with an increasing SYNTAX score in favour of CABG, with a significant survival benefit vs PCI in patients with a score of ≥33, said Thuijs. This was more apparent among patients with more complex three-vessel CAD, while SYNTAX score was not associated with mortality in patients with left main disease.

“These data suggest that PCI can be an alternative to CABG not only in patients with relatively non-complex left main lesions, but also in patients with more complex disease, as also demonstrated in our analyses according to SYNTAX scores,” said the researchers.

The researchers noted that the drug-eluting stents used in SYNTAX are no longer in use, with newer options linked to improved short-term mortality rates. [Lancet 2013;382:1879-1888]

Other factors that should be considered when deciding revascularization procedure include the potential for post-intervention stroke, myocardial infarction, graft occlusion, and stent thrombosis, they said.

Previous trials evaluating these two strategies have been limited by the enrolment of patients with low-severity disease and short-term follow-up, said Professors David Taggart from the University of Oxford, Oxford, and Domenico Pagano from University Hospital Birmingham, Birmingham, UK, in a commentary. [Lancet 2019;doi:10.1016/S0140-6736(19)32040-9]

“[The availability of long-term data shows that] in the absence of medical contraindications or patient preference, [there is] a clear mandate to expand the role of CABG and to adopt a more cautious indication for PCI,” they said.