Comparison of Intravascular Ultrasound-guided With Optical Coherence Tomography-guided Percutaneous Coronary Intervention for Left Main Distal Bifurcation Lesions (ISOLEDS)

ISOLEDS

Patient / Population Intervention / Exposure Comparison Outcome

In 664 patients undergoing PCI of a distal left main bifurcation, OCT guidance was non-inferior to IVUS guidance for target lesion failure at 12 months.

N

664patients

Design

Prospective, multicentre (about 20 tertiary hospitals in China), open-label, 1:1 randomised non-inferiority trial; 12-month clinical follow-up with optional angiographic assessment of the target lesion at 12 months

Endpoint

Target lesion failure within 12 months after the procedure

Relevance

2Important — one of several pillars.

ResultTarget lesion failure at 12 months occurred in 14.4% with OCT and 19.6% with IVUS (adjusted HR 0.90, 95% CI 0.59–1.36; P = 0.0003 for non-inferiority) over a median 362 days of follow-up.

Zeng Y, et al. Presented at ESC Congress 2026, Hot Line 11, 31 August.

Discussion & critique

The distal left main bifurcation is where intravascular imaging earns its keep, and the question was never whether to image but which modality: OCT sees the vessel wall in detail but needs contrast and struggles with ostial views, IVUS penetrates deeper and needs neither. At 664 patients the two were interchangeable, with a numerically lower event rate under OCT that the confidence interval does not support as real. This settles operator choice rather than practice — use whichever the laboratory does well.