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

Abstract

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.

Conflict of interest statement

Dr De Maria reports speaker fees from Miracor Medical SA and research grants from Abbott and Philips. Dr Testa reports fees as medical proctor for Boston Scientific, Meril, Concept Medical, Abbott, Philips and advisory board member and/or speaker fees and/or institutional research grant from Boston Scientific, Philips, Abbott, Medtronic, Terumo, Concept Medical. Dr de la Torre Hernandez reports receipt of grants/research supports from Abbott Medical, Biosensors, Bristol Myers Squibb, Amgen and receipt of honoraria or consultation fees from Boston Scientific, Medtronic, Biotronik, Astra Zeneca, Daiichi-Sankyo. Dr Bedogni reports fees as medical proctor for BSCI, Meril, Medtronic, Terumo and advisory board member and/or speaker fees and/or institutional research grant from Boston Scientific, Philips, Abbott, Medtronic, Terumo, Concept Medical. Prof Banning reports institutional grant for fellowship form Boston and speaker fees Boston, Phillips and Miracor Medical SA. Dr Spitzer declares that the sponsor of the study is the European Cardiovascular Research Institute (ECRI), in which he is a board member, and the research organization executing the study is Cardialysis, in which he is the chief medical officer. Dr Scarsini, Dr Terentes-Printzios, Dr Emfietzoglou have no conflict of interest to declare. In specific relationship with the study funders: • Boston Scientific has provided research grant support to Dr Testa, Dr Bedogni and Prof Banning • Boston Scientific has provided speaker fees/consultancy fees/proctor fees to Dr Testa, Dr de la Torre Hernandez, Dr Bedogni and Prof Banning • Philips has provided research grant support to Dr De Maria, Dr Testa and Dr Bedogni • Philips has provided speaker fees/consultancy fees/proctor fees to Dr Testa, Dr Bedogni and Prof Banning We confirm that: “This does not alter investigators’ adherence to PLOS ONE policies on sharing data and materials.”

Figures

Fig 1. Schedule of enrolment, interventions, and assessments.

(PCI: percutaneous coronary intervention; ECG: electrocardiogram; IVUS: intravascular ultrasound).

Fig 2. Flow diagram showing patient inclusion, randomization and follow-up in the OPTIMAL trial.

(IVUS: intravascular ultrasound; LAD: left anterior descending; LCx: left circumflex; LM: left main; MI: myocardial infarction; PCI: percutaneous coronary intervention; SAE: serious adverse event; ULMCA: unprotected left main coronary artery).

Fig 3. Example of IVUS-guided stent optimization following the OPTIMAL-optimization criteria.

Before optimization, IVUS showed stent underexpansion at the ostium of the LAD (stent area 5.42 mm2 [target > 6 mm2]), at the ostium of the LCx (stent area 4.90 mm2 [target > 5 mm2]) and in the proximal LCx (minimum stent area 4.74 mm2 [target > 5 mm2] accounting for 69.8% of the distal reference area [target > 90%]) (Red boxes in the upper half of the figure). Further postdilation on the LAD and LCx was performed, completing with FKI and final POT. After optimization, IVUS confirmed achievement of stent expansion targets in all segments, including those who appeared initially suboptimally expanded (Green boxes in lowed half of the figure). (LAD: left anterior descending; LCx: left circumflex; LMCA: left main coronary artery; MSA: minimal stent area; PB: plaque burden; POC: polygon of convergence; SA: stent area).