PARIS – The first-ever head-to-head randomized trial comparing clinical outcomes of optical coherence tomography and intravascular ultrasound (IVUS) for guidance of percutaneous coronary intervention with a second-generation drug-eluting stent has ended in a draw.
“The clinical outcomes in both OCT-guided PCI and IVUS-guided PCI were excellent in the OPINION study,” Dr. Takashi Kubo reported at the annual congress of the European Association of Percutaneous Cardiovascular Interventions.
The form of OCT used in this randomized trial is called optimal frequency domain imaging (OFDI). On the strength of the OPINION results, OFDI deserves to get an upgrade in the PCI treatment guidelines, said Dr. Kubo of Wakayama (Japan) University.
He noted that the 2014 European Society of Cardiology guidelines give IVUS a Class IIa recommendation in selected patients to optimize stent implantation, with a Level of Evidence of B (Eur Heart J. 2014 Oct 1;35:2541-619). The guidelines give OCT (optimal coherence tomography), the more recent and less-studied technology, a Class IIb, Level of Evidence C.
“Our results might influence the next ESC guidelines,” according to Dr. Kubo. “OCT use during PCI should have a Class IIa recommendation.”
The OPINION trial was a prospective, 42-site Japanese study in which 800 patients scheduled for PCI with the Terumo Nobori biolimus-eluting resorbable polymer stent were randomized to an OFDI- or IVUS-guided procedure. All participants underwent follow-up coronary angiography at 8 months and clinical assessment at 12 months.
The primary study endpoint was target vessel failure at 12 months post-PCI, a composite comprising cardiac death, target vessel–related MI, or clinically driven target vessel revascularization. The rate was 5.2% in the OFDI group and statistically similar at 4.9% in the IVUS arm. No cases of contrast-induced nephropathy occurred in either study arm, and stroke rates in both groups were similarly low.
Also noteworthy was the finding that the two intracoronary imaging technologies resulted in similar rates of procedural change: 38% of patients in the OFDI group had a procedural change as result of the imaging findings, as did 36% of the IVUS group. Examples of these procedural changes included upsizing the pre- or postdilatation balloon size or pressure, addition of an another stent, or the use of a distal protection device.
In Japan, where both OCT and IVUS during PCI are routinely reimbursed, roughly 80% of PCI patients undergo one of the two intracoronary imaging procedures. In the United States and Europe, the situation is reversed, Dr. Kubo observed.
Discussant Dr. Ron Waksman agreed with Dr. Kubo that the OPINION results warrant reconsideration of OCT’s Class IIb recommendation in the ESC PCI guidelines. But he thinks the study has a major limitation.
“In my view, this was a missed opportunity to include an angiographically guided PCI arm to establish the superiority of invasive imaging over angiographically guided PCI,” said Dr. Waksman of the MedStar Heart Institute in Washington. While he noted that a recent meta-analysis of 20 studies in more than 29,000 patients concluded that IVUS-guided implantation of drug-eluting stents was associated with a 38% reduction in the risk of mortality, a 23% decrease in major adverse cardiovascular events, and a 41% reduction in stent thrombosis, compared with angiographically guided PCI (BMC Cardiovasc Disord. 2015 Nov 17;15:153), given the inherent limitations of meta-analyses he’s not convinced that cardiologists really need imaging guidance.
“ILUMIEN III, to my view, is the right study design because it randomizes patients to OCT guidance, IVUS guidance, or angiographic guidance to see if there are important differences. We will have to wait for the ILUMIEN III study results to prove the superiority of invasive imaging over angiographically guided PCI,” according to Dr. Waksman.
It’s anticipated that the ILUMIEN III trial will be ready for presentation at EuroPCR 2017.
The OPINION trial was sponsored by Terumo. Dr. Kubo is a consultant to and recipient of an institutional research grant from the company.