Intravascular Imaging Bests Angiography for Complex PCI
NEW ORLEANS – In patients undergoing percutaneous intervention (PCI) for complex coronary lesions, intravascular imaging is superior to angiography for reducing the risk of target lesion failure (TLF), according to results of a randomized trial.
Previous studies have produced the same conclusion, but the advantage was demonstrated this time in a multicenter well-powered randomized trial, principal investigator Joo Yong Hahn, MD, PhD, said at the joint scientific sessions of the American College of Cardiology and the World Heart Federation.
The earlier studies “were not definitive,” said Dr. Hahn, pointing out that even those that were randomized lacked sufficient duration of follow-up or were not inclusive of a broad array of types of complex PCI.
In this clinical outcomes–driven study, called RENOVATE-COMPLEX-PCI, 1,639 patients undergoing complex PCI in 20 South Korean treatment centers were randomized in a 2:1 ratio to PCI guided by intravascular imaging or angiography alone. There were nine types of complex PCI eligible for trial entry, including bifurcated lesions, long lesions (expected stent length ≥ 38 mm), total coronary occlusions, lesions requiring multiple stents, severely calcified lesions, and lesions in multiple vessels.
Intravascular imaging in the experimental arm could be performed with either intravascular ultrasound (IVUS) or optical coherence tomography (OCT), according to Dr. Hahn. Because one might be better than the other for specific patient and lesions characteristics, the type of intravascular imaging in the experimental group was selected at the discretion of the treating investigator, reported Dr. Hahn, of the Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University, Seoul.
The primary TLF endpoint was defined as death from cardiovascular causes, target-vessel-related MI, and target-vessel revascularization.
Risk reduction of > 35% observed
After a median of 2.1 years of follow-up, the lower TLF incidence in the group with PCI guided by intravascular imaging (7.7% vs. 12.3%) translated into a 36% reduction in risk (hazard ratio, 0.64; P = .008).
Intravascular imaging was associated with a numerical reduction of each component of TLF. In the case of death from cardiovascular causes, the confidence interval remained below the line of unity (HR 0.47; 95% CI, 0.24-0.93).
Although this was not true for target vessel–related MI (HR, 0.74, 95% CI, 0.45-1.22) or target vessel revascularization (HR, 0.66; 95% CI, 0.36-1.22), it was also true of TLF without procedural-related MI (HR, 0.59; 95% CI, 0.39-0.90) and cardiac death or target vessel–related MI (HR, 0.63; 95% CI, 0.42-0.93).
With few exceptions, all of the secondary outcomes “moved in the right direction” to favor intravascular imaging, including death from any cause (HR 0.71, 95% CI, 0.44-1.15), reported Dr. Hahn, who noted that the results were simultaneously published in the New England Journal of Medicine.
When compared, there were no major baseline differences in the 1,092 patients with PCI guided by intravascular imaging relative to the 547 guided by angiography. The median age was 65.5 years. Most (79%) were male. About half (51%) had an acute coronary syndrome and the remainder had stable ischemic heart disease. The proportions of patients with hypertension (61%), dyslipidemia (51%), and diabetes (38%) were substantial. About 18% of patients were current smokers, 24% had a previous PCI, and 7% had a previous MI.
Stent types were similar in the two groups, and they were delivered by radial access. Procedural success was achieved in about 98% of both groups. Almost all patients were discharged on a statin, aspirin, and a P2Y12 inhibitor, and the other specific postprocedural medications were comparable in the two groups.
Advantage of intravascular imaging consistent
Of the complex lesions, most (55%) had diffuse long coronary artery lesions, but other types of complex PCI, including bifurcated lesions (22%), chronic total occlusions (20%), severely calcified lesions (14%), and ostial lesions of a major coronary artery (15%) were represented. Across these lesion types, intravascular imaging was favored over angiography for TLF at least numerically. The potential exceptions were lesions requiring at least three stents (HR, 1.24; 95% CI, 0.49-3.18), but confidence intervals were wide.
The trial was unblinded, but Dr. Hahn reported that imaging analyses were performed at a core laboratory and events were adjudicated by a committee with members unaware of trial group assignments.
One unanswered question is cost. Because intravascular imaging adds cost to PCI relative to angiography, cost-effectiveness analyses are needed to provide context for the decision to use this approach in all complex PCI patients. These analyses are planned.
Based on the consistency of these trial results with previous studies, almost all of which showed the same thing, “the intravascular imaging world has spoken,” said Wayne B. Batchelor, MD, director of interventional cardiology, Inova Heart and Vascular Institute, Fairfax, Va. “The only question now is when will the interventional community is going to listen.”
Dr. Batchelor predicted that these data will change the mindset of many practitioners “to shift the debate to why not do it [intravascular imaging] from why do it.”
“Only about 15% of PCI is performed with intravascular imaging in the United States, and these [results] argue that this number needs to go up,” Dr. Batchelor said. Although he said there are technical reasons, such as diffuse lesions or small vessels, that prevent intravascular imaging from being used in every complex patient, he suggested the data are compelling.
“If you apply this to the one million patients undergoing PCI in the United States, this will translate potentially into tens of thousands of patients protected from the TVF endpoint,” Dr. Batchelor said.
Dr. Hahn reports no potential conflicts of interest, but this investigator-initiated trial received funding from Boston Scientific and Abbott Vascular. Dr. Batchelor reports financial relationships with Abbott Vascular, Boston Scientific, Idorsia, Medtronic, and V-Wave Medical.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.
