IVUS-CHIP and OPTIMAL Studies Probe Role of IVUS in Complex PCI and Left Main Disease

March 30, 2026—Routine intravascular ultrasound (IVUS) guidance during percutaneous coronary intervention (PCI) did not improve clinical outcomes compared with angiography guidance in two contemporary randomized trials presented at ACC.26 and published in The New England Journal of Medicine.

In the IVUS-CHIP trial, Roberto Diletti, MD, et al randomized 2,020 patients undergoing complex high-risk PCI to IVUS-guided PCI with prespecified optimization criteria or angiography-guided PCI. The cohort had a mean age of 69 years, 79.4% were men, and 27.4% presented with acute coronary syndrome. At a median follow-up of 19 months, the primary endpoint of target-vessel failure occurred in 13.9% of patients in the IVUS group and 11.1% in the angiography group (hazard ratio [HR], 1.25; 95% CI, 0.97-1.60; P = 0.08).

Procedural time was longer with IVUS guidance (88.8 vs 66.2 minutes), and postdilation was more frequent (91.3% vs 84.5%), although procedural complications were similar between groups (11.3% vs 10.2%). Investigators concluded that routine IVUS guidance did not lower the risk of target-vessel failure compared with angiography alone.

In an accompanying editorial, Adnan Kastrati, MD, noted that the findings highlight ongoing uncertainty about how best to integrate intracoronary imaging into PCI workflows, particularly given added procedural complexity and cost.

In a separate trial focused on left main disease, the OPTIMAL study randomized 806 patients with unprotected left main coronary artery disease to IVUS-guided or angiography-guided PCI. Patients had a mean age of 71.4 years, 78.4% were men, and 34.7% had diabetes, with a mean SYNTAX score of 29.7.

Study investigators Luca Testra, MD, et al reported that at a median follow-up of 2.9 years, the primary composite endpoint of stroke, myocardial infarction, revascularization, or death occurred in 33.7% of the IVUS group and 30.9% of the angiography group (HR, 1.11; 95% CI, 0.87-1.42; P = 0.40). Rates of individual endpoints were similar, including death (15.7% vs 15.1%), myocardial infarction (11.2% vs 10.9%), and repeat revascularization (12.0% vs 11.1%).

A higher incidence of stroke was observed in the IVUS group (3% vs 1%; HR, 3.11; 95% CI, 1.00-9.65), although overall safety events were otherwise comparable between groups. Procedure time was also longer with IVUS guidance (88.6 vs 63.9 minutes).

Investigators of the OPTIMAL trial noted that the findings may have implications for guideline recommendations supporting routine intracoronary imaging in left main PCI, particularly in high-volume centers with experienced operators. Additionally, in an accompanying editorial, Frederick G.P. Welt, MD, noted that the numerical imbalance in stroke warrants further investigation.