Use of intravascular imaging guidance for percutaneous coronary intervention (PCI) in patients with complex coronary artery lesions led to a lower risk of a composite of death from cardiac causes, target vessel-related myocardial infarction (MI) or clinically driven target revascularisation than procedures using only angiography.
This is the headline finding from the RENOVATE-COMPLEX-PCI study, a prospective, multicentre, open-label trial conducted in South Korea. Findings from the study were presented at the American College of Cardiology (ACC) 2023 Scientific Sessions (4–6 March, New Orleans, USA) and simultaneously published in the New England Journal of Medicine (NEJM).
Investigators randomised 1,639 patients in a 2:1 ratio to undergo either intravascular imaging-guided PCI (n=1,092) or angiography-guided PCI (n=547), assessing the outcome of each approach against the composite primary endpoint of cardiovascular death, target-vessel MI, or clinically driven target-vessel revascularisation, as well as the safety of the procedures.
At ACC 2023 in New Orleans, Joo-Yong Hahn (Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, South Korea) reported that at a median follow-up of 2.1 years, a primary endpoint event occurred in 76 patients (cumulative incidence 7.7%) in the intravascular imaging group and in 60 patients (cumulative incidence 12.3%) in the angiography group (hazard ratio [HR] 0.64; 95 confidence interval [CI] 0.45 to 0.89; p=0.008).
Death from cardiac causes occurred in 16 patients (cumulative incidence 1.7%) in the intravascular imaging group and in 17 patients (cumulative incidence 3.8%) in the angiography group; target-vessel-related myocardial infarction occurred in 38 (cumulative incidence 3.7%) and 30 (cumulative incidence 5.6%), respectively; and clinically driven target-vessel revascularisation in 32 (cumulative incidence, 3.4%) and 25 (cumulative incidence, 5.5%), respectively. There were no apparent between-group differences in the incidence of procedure-related safety events.
PCI using second-generation drug-eluting stents has markedly reduced rates of stent- or target vessel-related adverse clinical events, the study team writes in their NEJM paper, noting however that patients with complex coronary artery lesions often have worse clinical outcomes.
“During PCI procedures, imaging with intravascular sonography and optical coherence tomography (OCT) provides useful information about lesion characteristics and is used to select the appropriate stent size, to determine the stent landing zone in the coronary artery, to determine if the stent is not well expanded or if there is a stent edge dissection, which can increase the risks of stent thrombosis, MI and repeat revascularisation,” the study team writes.
Previous randomised trials have shown lower rates of major adverse clinical events after intravascular ultrasonography-guided PCI than after angiography-guided PCI but have not been considered to be definitive due to their limited sample size of the inclusion of highly-selected coronary lesion subsets, the investigators add.
RENOVATE-COMPLEX-PCI was set up with the intention to investigate whether intravascular imaging-guided PCI would improve outcomes as compared with angiography-guided PCI in patients with complex coronary artery lesions.
Involving 20 centres throughout South Korea, the trialists enrolled patients with complex coronary artery lesions defined as true bifurcation lesions, with a side branch diameter of at least 2.5mm, a chronic total occlusion, unprotected left main coronary artery disease, long coronary artery lesions, multivessel PCI, a lesion involving in-stent restenosis, a severely calcified lesion, or ostial lesions of a major epicardial coronary artery.
For patients randomised to the intravascular imaging group, the decision to use intravascular ultrasonography or OCT was at the discretion of the operator, and could be used any time during the procedure, but was mandated after stent implantation to determine whether the stented segment of the vessel was optimised.
In their NEJM paper, the investigators note that there were limitations to the trial, including that it was unblinded—though the study team sought to minimise the risk of bias through the use of “precisely defined” endpoint criteria. Further to this, they note that intravascular imaging-defined stent optimisation occurred in only 45.4% of patients, with one possible explanation being that the trial focused solely on complex lesions.
Another limitation listed by the authors was that stent optimisation in the angiography group could only be assessed via quantitative coronary angiography, and the proportion of target lesions evaluated by intravascular imaging before stenting was only about 25% as the trial protocol mandated intravascular imaging only after stent deployment. Furthermore, more than half of the trial population was enrolled at a single centre, and the investigators note that the population comprised only East Asian patients, which, they state, may limit generalisability. Analysis of the cost of the addition of intravascular imaging to the procedure may also be required before the findings can inform clinical decision making, the study team adds.
