All-comEr Registry of OCT (AERO) to Investigate the MLD-MAX Algorithm for OCT-guided-precision-PCI in Daily Routine: Rationale and Study Design of ILUMIEN-V-AERO.

Background: Despite class 1 recommendations and clinical evidence supporting optical coherence tomography (OCT), its adoption is limited. While randomised controlled trials show clinical benefits of OCT under strict protocols, its real-world performance is unclear. Aims and methods: All-comEr Registry of OCT (AERO) to Investigate the MLD-MAX Algorithm for OCT-guided-precision-PCI in Daily Routine (ILUMIEN-V-AERO; NCT05324683) is a prospective, multicentre OCT registry aiming to recruit 2,000 patients across sites in the UK, Germany and Saudi Arabia. The study seeks to evaluate the real-world use of an algorithmic approach to OCT-guided percutaneous coronary intervention (PCI) (MLD-MAX) and directly compares its outcomes to those from the ILUMIEN-IV randomised controlled trial. The primary endpoint for this comparison is post-PCI minimum stent area relative to the reference segments. Secondary endpoints include OCT imaging assessments (minimum stent area, edge dissection, stent malapposition, mean stent expansion, plaque protrusion, reference segment disease), procedural outcomes (procedural and fluoroscopy time, contrast use, renal replacement therapy) and clinical endpoints (a composite endpoint of target lesion failure [cardiac death, ischaemia-driven target lesion revascularisation, target vessel MI] and unplanned hospitalisation for unstable angina). All patients will undergo clinical follow-up at 30 days and 6 months to assess target lesion failure. Beyond the inclusion criteria of the ILUMIEN-IV trial, this study will explore the role of OCT in diagnosing acute coronary syndrome, its application in guiding drug-coated balloon PCI and the impact of core laboratory support and critical evaluation on operator performance. Conclusion: ILUMIEN-V-AERO is a large, prospective registry designed to assess the real-world performance of OCT and provide insights into its role in underexplored areas of PCI guidance.