Key Points
• In the randomized OPTIMAL trial, IVUS-guided PCI did not reduce the risk of the primary patient oriented composite endpoint compared with angiography-guided PCI in patients with unprotected left main coronary artery disease.
• At a median follow up of 2.9 years, the primary endpoint occurred in 33.7% of the IVUS-guided group and 30.9% of the angiography-guided group, with a hazard ratio of 1.11 and a 95% confidence interval of 0.87 to 1.42.
• Device oriented and vessel oriented composite endpoints were also similar between strategies, despite nearly universal IVUS use in the imaging-guided arm.
PCI is an accepted alternative to CABG in selected patients with left main disease, but the procedure remains technically demanding, particularly when bifurcation technique, stent expansion, and apposition may influence long term outcomes. Although prior trials in broader PCI populations suggested benefits of IVUS guidance, no large, randomized trial had specifically focused on unprotected left main PCI.
The OPTIMAL trial presented as Late Breaking Clinical Trial at ACC 2026 with simultaneous publications in NEJM was an investigator-initiated, international, open-label, randomized, controlled trial, we assigned patients undergoing complex PCI to either IVUS-guided PCI, performed with the use of prespecified stent-optimization criteria, or angiography-guided PCI [NCT04111770] .
OPTIMAL was conducted in Italy, Spain, and the United Kingdom. A total of 806 patients were randomized, with 401 assigned to IVUS-guided PCI and 405 to angiography-guided PCI. The primary endpoint was a patient-oriented composite of death from any cause, stroke, myocardial infarction, or any revascularization at longest follow up.
Baseline characteristics were generally balanced between groups. Mean age was about 71 years, nearly 79% of participants were men, and average left ventricular ejection fraction was about 53%. Procedurally, IVUS was used at any time in 98.7% of patients in the IVUS arm compared with 3.0% in the angiography arm. Procedure time was longer with IVUS guidance, 88.6 minutes versus 63.9 minutes, while periprocedural complication rates were similar at 7.4% and 7.2%, respectively.
At a median follow up of 2.9 years, the primary endpoint occurred in 135 patients, or 33.7%, in the IVUS-guided group and in 125 patients, or 30.9%, in the angiography-guided group, yielding a hazard ratio of 1.11. Secondary composite endpoints were also similar. The device oriented composite endpoint occurred in 22.4% of the IVUS-guided group and 20.5% of the angiography-guided group, while the vessel oriented composite endpoint occurred in 24.2% and 21.5%, respectively.
The investigators suggested that the neutral result may reflect the high expertise of participating centers and strong adherence to contemporary procedural standards, which may have reduced differences between treatment strategies. Overall, OPTIMAL showed that in experienced, high-volume centers, routine IVUS guidance did not improve major clinical outcomes compared with angiography guidance alone for PCI of unprotected left main disease.