ISOLEDS Study Compares OCT and IVUS for Complex PCI and Stent Implantation

September 17, 2026—Results from the ISOLEDS trial showed that optical coherence tomography (OCT) was noninferior to intravascular ultrasound (IVUS) to guide percutaneous coronary intervention (PCI) with stent implantation in patients with left main coronary artery disease. The findings were presented at the European Society of Cardiology’s ESC Congress 2026.

The ESC press release noted that IVUS provides good tissue penetration and a large field of view for assessing lesions, selecting devices, and optimizing stent implantation, whereas OCT provides higher-resolution assessment of the vessel lumen and stent.

Professor Yong Zeng, MD, from Beijing Anzhen Hospital, Capital Medical University in Beijing, China, serves as Principal Investigator of the ISOLEDS trial.

“Although OCT-guided PCI has been shown to be noninferior to IVUS-guided PCI in a broad PCI population, direct randomized evidence in true distal left main bifurcation lesions has been lacking,” commented Prof. Yong Zeng in the ESC press release. “We conducted a dedicated randomized trial to determine whether OCT guidance is noninferior to IVUS guidance in this setting.”

As summarized in the ESC press release, the ISOLEDS trial enrolled 664 patients with true distal left main bifurcation lesions at 24 centers in China. The mean age of the patients was 63.5 years and 22.1% were women.

In the open-label, noninferiority trial, the patients were randomized (1:1) to OCT- or IVUS-guided PCI.

The study’s 12-month primary endpoint was target lesion failure (comprising cardiac death, target lesion–related myocardial infarction, or clinically driven target lesion revascularization), noted the press release.

ESC reported that at median follow-up of 362 days, target lesion failure with OCT-guided PCI was noninferior to IVUS-guided PCI (12-month Kaplan–Meier estimates: 14.4% vs 19.6%; adjusted hazard ratio, 0.90; 95% CI, 0.59-1.36; P for noninferiority = .0003). The finding remained consistent when periprocedural myocardial infarction was excluded and was supported by the per-protocol and competing-risk analyses.

In the ESC press release, Prof. Zeng further addressed the implications of the study findings, commenting, “ISOLEDS shows that OCT guidance may be considered an alternative to IVUS guidance for appropriately selected patients undergoing PCI for true distal left main bifurcation lesions. The findings do not establish equivalence or superiority. In practice, selection of the imaging modality should account for coronary anatomy, image-acquisition feasibility and local expertise.”