Optical coherence tomography-guided versus angiography-guided percutaneous coronary intervention for patients with complex lesions (OCCUPI): an investigator-initiated, multicentre, randomised, open-label, superiority trial in South Korea

Background Despite the detailed imaging information provided by optical coherence tomography (OCT) during percutaneous coronary intervention (PCI), clinical benefits of this imaging technique in this setting remain uncertain. The aim of the OCCUPI trial was to compare the clinical benefits of OCT-guided versus angiography-guided PCI complex lesions, assessed as the rate of major adverse cardiac events at 1 year. Methods This investigator-initiated, multicentre, randomised, open-label, superiority trial conducted at 20 hospitals in South Korea enrolled patients aged 19-85 years for whom PCI with drug-eluting stents was clinically indicated. After diagnostic angiography, clinical and angiographic findings were assessed to identify patients who met criterion of having one or more complex lesions. Patients were randomly assigned 1:1 to receive PCI with OCT guidance (OCT-guidance group) or angiography guidance without OCT (angiography-guidance group). Web-response permuted-block randomisation (mixed blocks of four or six) was used at each participating site to allocate patients. The allocation sequence was computer-generated by an external programmer who was not involved in the rest of trial. Outcome assessors were masked to group assignment. Patients, follow-up health-care providers, and analysers were not masked. PCI was done according to conventional standard methods with everolimus-eluting stents. The primary endpoint was major adverse cardiac events (a composite of cardiac death, myocardial infarction, stent thrombosis, or ischaemia-driven target-vessel revascularisation), 1 year after PCI. The primary analysis done in the intention-to-treat population. The margin used to establish superiority was 1<middle dot>0 as a hazard ratio. This is registered with ClinicalTrials.gov (NCT03625908) and is completed. Findings Between Jan 9, 2019, and Sept 22, 2022, 1604 patients requiring PCI with drug-eluting stents for complex lesions were randomly assigned to receive either OCT-guided PCI (n=803) or angiography-guided PCI (n=801). 1290 (80%) of 1604 patients were male and 314 (20%) were female. The median age of patients at randomisation 64 years (IQR 57-70). 1588 (99%) patients completed 1-year follow-up. The primary endpoint occurred in 37 (5%) 803 patients in the OCT-guided PCI group and 59 (7%) of 801 patients in the angiography-guided PCI group (absolute difference -2<middle dot>8% [95% CI -5<middle dot>1 to -0<middle dot>4]; hazard ratio 0<middle dot>62 [95% CI 0<middle dot>41 to 0<middle dot>93]; p=0<middle dot>023). Rates of stroke, bleeding events, and contrast-induced nephropathy were not significantly different across the two groups. Interpretation Among patients who required drug-eluting stent implantation for complex lesions, OCT guidance resulted in a lower incidence of major adverse cardiac events at 1 year compared with angiography guidance. These findings indicate the existence of a therapeutic benefit of OCT as an intravascular imaging technique for PCI guidance in patients with complex coronary lesions.