A multi-center, international, randomized, 2-year, parallel-group study to assess the superiority of IVUS-guided PCI versus qualitative angio-guided PCI in unprotected left main coronary artery (ULMCA) disease: Study protocol for OPTIMAL trial

BACKGROUND: Percutaneous coronary intervention (PCI) is used increasingly for revascularization of unprotected left main coronary artery (LMCA) disease. Observational studies and subgroup analyses from clinical trials, have suggested a possible benefit from the use of intravascular ultrasound (IVUS) guidance when performing unprotected LMCA PCI. However, the value of imaging with IVUS has never been proven in an appropriately powered randomized clinical trial. The OPtimizaTIon of Left MAin PCI With IntravascuLar Ultrasound (OPTIMAL) trial has been designed to establish whether IVUS-guided PCI optimization on LMCA is associated with superior clinical outcomes when compared with standard qualitative angiography-guided PCI. METHODS: The OPTIMAL trial is a randomized, multicenter, international study designed to enroll a total of 800 patients undergoing PCI for unprotected LMCA disease. Patients will be randomized in a 1:1 fashion to IVUS-guided PCI versus angiogram-guided PCI. In patients allocated to the angiogram-guided arm, use of IVUS is discouraged, unless there are safety concerns. In patients allocated to the IVUS guidance arm, pre-procedural IVUS assessment is highly recommended, whilst post-procedural IVUS assessment is mandatory to confirm appropriate stenting result and/or to guide stent result optimization, according to predefined criteria. Patients will be followed up to 2 years after the index procedure. The primary outcome measure is the Academic Research Consortium (ARC) patient-oriented composite endpoint (PoCE) which includes all-cause death, any stroke, any myocardial infarction and any repeat revascularization at 2 years follow-up. DISCUSSION: The OPTIMAL trial aims to provide definitive evidence about the clinical impact of IVUS-guidance during PCI to an unprotected LMCA. It is anticipated by the investigators, that an IVUS-guided strategy will be associated with less clinical events compared to a strategy guided by angiogram alone. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04111770. Registered on October 1, 2019.