OCT guidance showed non-significant MACE reduction in true unprotected left main bifurcation disease compared to angiography

Photo by Brett Jordan / Unsplash

EuroIntervention : journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology Published May 15, 2026 Medically reviewed May 15, 2026 Study authors: Holck Emil N, Andreasen Lene D, Neghabat Omeed, Laanmets Peep, Mogensen Lone J H, Spratt James C, Be… PubMed ↗ DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Note non-significant MACE reduction with OCT guidance in true left main bifurcation lesions; feasibility was high.

This randomized controlled trial evaluated 227 patients with true unprotected left main bifurcation lesions. The study compared Optical coherence tomography (OCT) guidance against angiographic guidance for percutaneous coronary intervention. The primary outcome was the composite of major adverse cardiac events, defined as cardiac death, any myocardial infarction, or target lesion revascularisation.

Feasibility results indicated that 98% of cases had successful pre-stenting pullbacks and 96% had successful final pullbacks. However, only 43% of patients achieved an analysable proximal left main coronary artery stent edge. In the remaining patients, 5% were limited by insufficient image quality. The study did not report adverse events, discontinuations, or tolerability data.

The primary outcome showed a hazard ratio of 0.78 for major adverse cardiac events in the OCT group compared to the angiography group. The 95% confidence interval was 0.39-1.51, indicating a non-significant reduction. A limitation noted was that visibility of the left main coronary artery ostium was limited by short pullbacks, insufficient clearance, or guide catheter shadowing. The practice relevance concluded that OCT-guided PCI in true left main bifurcation lesions was clinically feasible.

Study Details

Study typeRct

Sample sizen = 227

EvidenceLevel 2

PublishedMay 2026

PMID42137920

View Original Abstract ↓

BACKGROUND: Dedicated randomised studies on intravascular imaging guidance in unprotected left main coronary artery (LMCA) disease are lacking. AIMS: We aimed to investigate the clinical feasibility of optical coherence tomography (OCT) guidance in percutaneous coronary intervention (PCI) of true LMCA bifurcation lesions and to evaluate its prognostic impact compared with angiographic guidance. METHODS: Patients with true LMCA bifurcation lesions who were randomised to either OCT or angiographic guidance in the OCTOBER Trial were included. The feasibility of OCT guidance was assessed as the proportion of patients with successful and analysable OCT pullbacks before, during, and after stenting. Clinical outcomes between the two groups were compared based on the incidence of a composite of major adverse cardiac events (MACE), comprising cardiac death, any myocardial infarction, or target lesion revascularisation. RESULTS: In total, 227 patients were included (OCT: 111, angiography: 116). OCT guidance was successful, with 98% of cases having a pre-stenting pullback performed and 96% a final pullback, as per protocol. The proximal LMCA stent edge was analysable in 43% of patients, and in the remaining 57%, only 5% were limited by insufficient image quality. No statistically significant difference in MACE was observed between the two groups (OCT: 14.4% vs angiography: 18.4%, hazard ratio 0.78, 95% confidence interval: 0.39-1.51). CONCLUSIONS: OCT-guided PCI in true LMCA bifurcation lesions was clinically feasible, but visibility of the LMCA ostium was limited by short pullbacks, insufficient clearance, or guide catheter shadowing. OCT guidance was associated with a non-significant reduction in MACE, consistent with the effect estimate in the main trial.