CABG superior to PCI for left main coronary artery disease, confirms NOBLE trial

PCI is associated with inferior clinical outcomes compared to CABG in patients with left main coronary artery disease, reveal 5-year data from the NOBLE trial.

Delhi: According to the study, percutaneous coronary intervention (PCI) carries a higher risk of major adverse cardiac or cerebrovascular events compared with coronary artery bypass grafting (CABG) in the revascularization of patients with left main coronary artery disease (CAD).

Morality was similar after the two procedures but patients treated with PCI had higher rates of non-procedural myocardial infarction (MI) and repeat revascularization.

The findings hold importance as PCI is increasingly used in the revascularisation of patients with left main coronary artery disease in place of the standard treatment, CABG. The safety and efficacy of PCI relative to CABG in patients with left main CAD is a hot topic at the moment amid growing controversy over the results of the other major clinical trial, EXCEL, which had been initially presented alongside NOBLE in 2016.

The NOBLE trial by Evald H Christiansen, Aarhus University Hospital, Aarhus, Denmark, and colleagues aimed to evaluate whether PCI was non-inferior to CABG in the treatment of left main coronary artery disease and reported outcomes after a median follow-up of 3·1 years. They reported updated 5-year outcomes of the trial.

The trial was done at 36 hospitals in nine northern European countries. It enrolled 1201 patients with left main CAD requiring revascularization. They were randomly assigned to receive PCI (n=598) or CABG (n=603) in the ratio 1:1.; 17 were subsequently lost to early follow-up. 592 patients in each group were included in this analysis.

Read Also: EXCEL TRIAL: Stents, bypass surgery equally safe, effective in left main heart disease

Key findings of the study include:

• At a median of 4·9 years of follow-up, the predefined number of events was reached for adequate power to assess the primary endpoint.


• Kaplan-Meier 5-year estimates of MACCE were 28% (165 events) for PCI and 19% (110 events) for CABG (HR 1·58); the HR exceeded the limit for non-inferiority of PCI compared to CABG.


• CABG was found to be superior to PCI for the primary composite endpoint.


• All-cause mortality was estimated in 9% after PCI versus 9% after CABG (HR 1·08; non-procedural myocardial infarction was estimated in 8% after PCI versus 3% after CABG (HR 2·99), and repeat revascularization was estimated in 17% after PCI versus 10% after CABG (HR 1·73).

"Inclusion of periprocedural myocardial infarction in primary composite endpoints was recommended by the Academic Research Consortium and in the universal definition of myocardial infarction, and the EXCEL investigators showed that large periprocedural myonecrosis was associated with increased 3-year mortality," the NOBLE investigators write. "This finding might have implications for standard clinical evaluation after revascularization. However, the inclusion of periprocedural myocardial infarction in a composite endpoint that also includes death is controversial, because the added events in long-term follow-up will then include patients that did not die from a periprocedural myocardial infarction."

"In revascularisation of left main coronary artery disease, PCI was associated with an inferior clinical outcome at 5 years compared with CABG. Mortality was similar after the two procedures but patients treated with PCI had higher rates of non-procedural myocardial infarction and repeat revascularization," they concluded.

The study, "Percutaneous coronary angioplasty versus coronary artery bypass grafting in the treatment of unprotected left main stenosis: updated 5-year outcomes from the randomised, non-inferiority NOBLE trial," is published in The Lancet.

DOI: https://doi.org/10.1016/S0140-6736(19)32972-1