Optical coherence tomography-guided PCI in left anterior descending versus non-left anterior descending lesions: a prespecified substudy of the OCCUPI trial.

The OCCUPI trial demonstrated the clinical benefit of optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI). However, whether the effect of OCT guidance differs according to diseased coronary vessel remains unclear. This prespecified substudy evaluated the consistency of clinical outcomes with OCT-guided PCI in left anterior descending (LAD) versus non-LAD lesions. Among 1,375 patients without left main disease, 888 had LAD lesions and 487 had non-LAD lesions. Patients were randomized to undergo PCI guided by either OCT or conventional angiography. The primary endpoint was 1-year major adverse cardiovascular events (MACE), defined as a composite of cardiac death, myocardial infarction, stent thrombosis, or ischemia-driven target-vessel revascularization (TVR). Outcomes were assessed by time-to-event analysis. In the LAD group, 1-year MACE occurred in 4.5% of patients treated with OCT-guided PCI and 5.5% treated with angiography-guided PCI, with no statistically significant difference (p = 0.456). In the non-LAD group, corresponding MACE rates were 4.6% and 7.7%, respectively (p = 0.099). There was no significant interaction between diseased vessel and PCI guidance strategy (p for interaction = 0.351). Ischemia-driven TVR occurred less frequently with OCT-guided PCI in both LAD and non-LAD lesions, without significant heterogeneity (p for interaction = 0.872). In complex coronary lesions, the clinical effect of OCT-guided PCI was consistent between LAD and non-LAD vessels, with fewer repeat revascularizations observed across diseased-vessel subgroups.