Patients with diabetes mellitus undergoing percutaneous coronary intervention (PCI) for left main (LM) bifurcation lesions continue to experience poorer cardiovascular outcomes despite advances in drug-eluting stents and procedural techniques. In a systematic review and meta-analysis presented at the EuroPCR 2026, investigators evaluated the impact of diabetes on clinical outcomes following LM bifurcation PCI.

The analysis was conducted according to PRISMA guidelines, with the protocol prospectively registered in the PROSPERO database. Investigators searched PubMed, the Cochrane Library, Web of Science, and Scopus through August 2025 for observational studies and clinical trials directly comparing outcomes between patients with and without diabetes undergoing PCI for LM bifurcation lesions.

Findings

• A total of six studies involving 12,494 patients were included.
• Patients with diabetes had significantly higher rates of major adverse cardiovascular events (MACE) between 9 months and 2 years after PCI, with risk ratios ranging from 1.73 to 1.92.
• Myocardial infarction risk remained elevated in patients with diabetes during mid- to long-term follow-up, with approximately two-fold higher risk observed up to 5 years (RR range 1.90–2.16).
• Cardiac mortality at 9 months was significantly higher in patients with diabetes (RR 1.96).
• Target lesion revascularization rates were significantly increased between 9 months and 2 years in patients with diabetes (RR range 1.61–1.82).
• No statistically significant association was observed between diabetes status and definite or probable stent thrombosis.
• The excess ischemic risk appeared more consistent with progressive atherosclerotic disease and non-target lesion failure rather than acute device-related complications.
• Adverse outcomes persisted despite the use of contemporary drug-eluting stents and optimized PCI strategies.

The study suggest that diabetes mellitus remains a strong predictor of adverse outcomes after LM bifurcation PCI, even in the era of modern coronary intervention.