BOSTON — Adding fuel to the controversy of revascularization for the left major disease, patients had better survival after coronary artery bypass grafting (CABG) surgery than percutaneous coronary intervention (PCI) in a nationwide pivotal all-inclusive trial.
The incidence of all-cause mortality remained greater up to 7 years after PCI versus CABG (adjusted HR 1.59, 95% CI 1.11-2.27), despite the use of different analytical methods to avoid confounding in the Swedish Coronary Angiography and Angioplasty Registry (SCAAR), according to Elmir Omerovic, MD, PhD, of Sahlgrenska University Hospital in Gothenburg, Sweden.
But in subgroup analysis, there was a significant interaction by age, such that people 80 and older lived longer after PCI for the major left disease, while younger patients did better with surgery, Omerovic reported at the Transcatheter Cardiovascular Therapeutics (TCT) meeting hosted by the Cardiovascular Research Foundation (CRF).
Results with limited mean survival time suggested that patients who would be expected to live at least 7 years gained an average of 6 months with CABG instead of PCI; for those with a shorter life expectancy, the estimated prolongation of life was less than 1 month.
Omerovic said the homecoming message is that surgeons should not operate on high-risk elderly patients with left head disease, adding another point of contention to the debate over stenting versus surgery for left head CAD.
While the 2016 NOBLE study results favored CABG, the EXCEL study concluded that there was no significant difference between the strategies. Controversy erupted when a leading EXCEL researcher publicly split from the group in 2019, crying over the unfair count of periprocedural MIs that penalized surgery.
Then, in a meta-analysis pooling these two studies of SYNTAX and PRECOMBAT, the researchers found that there was no statistically significant difference in 5-year all-cause mortality between PCI and CABG, although a Bayesian analysis showed a slightly longer lifespan after CABG suggested.
“The question has not been resolved and I think we will continue to discuss it for years to come,” Omerovic said at a TCT press conference.
Omerovic reported that the 30 participating hospitals in SCAAR were roughly split between those with more PCIs and those with more CABGs.
The registry included all people in Sweden with stable angina, unstable angina and non-ST segment elevation MI (NSTEMI) who had undergone coronary angiography since 2015 and had exited the major disease (>50% stenosis). Researchers found that these 10,254 individuals were roughly split between those who received PCI (52.6%) and those who underwent CABG (47.4%).
The two groups differed in several ways at baseline. For example, people selected for PCI were a few years older and showed more hyperlipidemia, prior MI, and prior revascularization procedures.
The prospect of selection bias was suggested by Ori Ben-Yehuda, MD, clinical researcher at CRF, who said he noted an early separation of the curves that was surprisingly favorable for CABG, despite the immediate risk of surgical complications.
“Your curves open immediately and very wide… It’s a bit counterintuitive,” agreed TCT session discussion leader Davide New Year, MD, of Azienda Ospedaliero-Universitaria Policlinico-Vittorio Emanuele in Catania, Italy.
Omerovic explained that the study was based on instrumental variable analysis — using each participating hospital’s preference for PCI or CABG as a source of randomness — and inverse probability weighting of propensity scores to help check for bias and confounding. .
Despite these efforts, he acknowledged that selection bias and residual confounding cannot be ruled out, given the observational nature of the study.
“You have the tools, the background, and the infrastructure to conduct a randomized controlled trial on exactly this, and this is what needs to be done if you really want the answer,” said Mount Sinai School TCT press conference panelist Roxana Mehran, MD. of Medicine in New York City.
She added that cardiovascular mortality would be a useful endpoint to assess in the setting of left head revascularization.
Omerovic and Ben-Yehuda have not disclosed any ties to the industry.
Capodanno revealed relationships with Amgen, Arena, Daiichi-Sankyo/Eli Lilly, Sanofi-Aventis and Terumo Medical, as well as an institutional relationship with Medtronic.
Mehran revealed multiple relationships with the industry.