Why is this study important?

• Left main coronary artery disease and diabetes mellitus (DM) are independently associated with high rates of cardiac morbidity and mortality.
• Historically, coronary artery bypass grafting (CABG) has been preferred over percutaneous coronary intervention (PCI) in left main coronary artery disease.
• Recent studies have shown that PCI in left main coronary artery disease has similar outcomes to CABG.

What question was this study supposed to answer?

• The current study was performed using a pooled analysis of four randomized control trials (SYNTAX, PRECOMBAT, NOBLE and EXCEL) to compare PCI versus CABG in patients with left main coronary artery disease who were judged to be suitable for either procedure. Patients were also grouped based on their DM status at randomization.
• The primary end point was all-cause mortality at 5 years.

What did the study show?

• At 5 years, regardless of method of revascularization (PCI or CABG), patients with DM had a significantly higher death rate as compared to those without DM (14.7% vs. 9.3%; adjusted hazard ratio [HR]: 1.62; 95% confidence interval [CI]: 1.32-2.00; P<0.001).
• There was no significant difference in 5-year mortality between the PCI and CABG groups [in patients with DM, the 5-year death rate was 14.1% in the CABG group and 15.3% in the PCI group (adjusted HR: 1.11; 95% CI: 0.82-1.52). In patients without DM, the death rate was 8.9% in the CABG group and 9.7% in the PCI group (HR: 1.08; 95% CI: 0.86-1.36)].
• In summary, both PCI and CABG are reasonable revascularization strategies in those patients with left main coronary artery disease suitable for either PCI or CABG and this is independent of the patient’s diabetes status.  

All editors: Sanjeev Nair, MD, FSCAI