When compared with angiography-guided PCI, IVUS-guided PCI was found to be not superior in patients with complex coronary arteries according to results from the IVUS-CHIP trial or in patients with unprotected left main coronary artery disease (LM-CAD) according to results from the OPTIMAL trial. Both trials were presented in a Late-Breaking Clinical Trial session at ACC.26 in New Orleans.

IVUS-CHIP, simultaneously published in NEJM, was an investigator-initiated, European, open-label trial that examined the efficacy of IVUS-guided PCI, for which there is limited evidence from current European practice and low adoption in Western countries.

Roberto Diletti, MD, et al., randomized 2,020 patients with complex coronary arteries 1:1 to IVUS-guided PCI with prespecified stent-optimization criteria or angiography-guided PCI. Their mean age was 69 years, 79% were men and 27% presented with an acute coronary syndrome. The primary endpoint was target-vessel failure (TVF), defined as a composite of death from cardiac causes, target-vessel myocardial infarction or clinically indicated target-vessel revascularization.

The preprocedure SYNTAX score was 25 in both groups and most lesions were type B2 or C. The mean procedure duration was 89 minutes for IVUS-guided PCI and 66 minutes for angiography-guided PCI. Dilation with balloon angioplasty after stent implantation was performed in 91% of the IVUS-guided procedures and in 84% of the angiography-guided procedures.

Results at the mean 19-month follow-up showed that the primary outcome of TVF occurred in 14% of patients in the IVUS-guided cohort and 11% of patients in the angiography-guided cohort (hazard ratio [HR], 1.25; p=0.08). Complications were recorded in 11.3% and 10.2% of the procedures in the respective cohorts.

“Among patients undergoing complex high-risk PCI, a strategy of routine IVUS-guided PCI performed with the use of prespecified stent-optimization criteria was not associated with a lower risk of [TVF] than angiography-guided PCI alone,” conclude the authors.

In an accompanying editorial comment, Adnan Kastrati, MD, writes about issues with IVUS-guided PCI. “We have yet to fully establish how to leverage the unique information provided by intravascular imaging to guide both the indications for and the execution of PCI in a way that justifies the associated increase in procedural complexity and cost.”

In the international, multicenter, open-label OPTIMAL trial, also simultaneously published in NEJM, 806 patients with unprotected LM-CAD were randomized, with 401 assigned to receive IVUS-guided PCI and 405 assigned to receive angiography-guided PCI. The mean age of the patients was 71 years, 78% were men and 35% had diabetes. The mean SYNTAX score was 29.7.

At a median follow-up of 2.09 years, the primary endpoint of patient-oriented composite of any stroke, MI, revascularization or death from any cause occurred in 34% of patients in the IVUS cohort and 31% of patients in the angiography cohort (HR, 1.11; p=0.40). A similar incidence of death (15%), MI (11%) or revascularization (about 11%) was observed in both cohorts. Additionally, the rate of procedure-related and overall safety events was similar in the two cohorts.

Luca Testa, MD, et al., note there may be implications for guideline recommendations. “The results of the OPTIMAL trial may challenge the requirement to always use intracoronary imaging guidance when performing PCI in stenoses of the left main coronary artery, which suggests that angiography alone may be appropriate when procedures are performed by expert IVUS operators at high-volume centers.”

In an accompanying editorial comment, Frederick G.P. Welt, MD, FACC, notes that the incidence of stroke differed between the cohorts, with 12 patients (3%) in the IVUS cohort having a stroke and four patients (1%) in the angiography group having a stroke; the median time from procedure to stroke was 19 months.

“The authors suggest that this result may be due to chance, and previous studies of IVUS have not supported an increased incidence of stroke. However, one cannot exclude the possibility that the extra time and manipulation associated with IVUS (or the care received after the procedure) may have played a role and should be addressed in future trials,” he writes.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Interventions and Imaging, Angiography, Echocardiography/Ultrasound, Nuclear Imaging

Keywords: ACC Annual Scientific Session, ACC26, New Orleans, Ultrasonography, Interventional, Angiography, Percutaneous Coronary Intervention