Drug-eluting stent implantation guided by intravascular ultrasound (IVUS) is associated with significantly lower rates of target vessel failure at three-year follow-up compared to procedures performed using angiographic guidance.
This is according to the latest data from the multicentre, randomised ULTIMATE trial, published in JACC: Cardiovascular Interventions. One-year findings of the trial were first reported at the 2018 Transcatheter Cardiovascular Therapeutics (TCT) meeting (21–25 September, San Diego, USA), pointing to a significantly lower rate of clinically-driven target vessel failure in all-comers patients after 12 months.
In the present study, authors Xiao-Fei Gao (Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China) and colleagues report on 1,448 patients undergoing drug-eluting stent implantation who were randomly assigned to either IVUS guidance or angiographic guidance in the ULTIMATE trial, and followed out to three years.
Patients were eligible to participate in this trial if they had silent ischaemia, stable or unstable angina, or myocardial infarction (MI) with more than 24 hours between onset of chest pain and admission and de novo coronary lesions requiring drug-eluting stent implantation.
Patients were enrolled from August 2014 to May 2017 and randomly assigned to undergo IVUS-guided or angiography-guided stent implantation in a 1:1 ratio immediately after coronary angiography.
All patients were prescribed a loading dose of aspirin (300mg) and a P2Y12 inhibitor (clopidogrel 600mg or ticagrelor 180mg) if not receiving antiplatelet therapy before the procedure. After the procedure, all patients were treated with 100mg/day aspirin indefinitely and 75mg/day clopidogrel (or ticagrelor 90mg twice a day) for at least one year, the study team reports.
The patient groups were well matched, Gao and colleagues note, with a mean age of 65.2 years in the IVUS-guided group, and 65.9 years in the angiographic guidance group (p=0.19). Diabetes was present in 30.6% of enrolled patients, and 78.5% of patients presented with acute coronary syndromes (ACS). Multivessel disease was found in 54.9% of patients. Larger stents were implanted in the IVUS guidance group, with more frequent post-dilation using larger noncompliant balloons at higher pressures.
The primary endpoint for the study was the risk for target vessel failure at three years, while the study’s safety endpoint was definite or probable stent thrombosis.
The study team reports that target vessel failure occurred in 47 patients (6.6%) in the IVUS-guided group and in 76 patients (10.7%) in the angiography-guided group (p=0.01), driven mainly by the decrease in clinically-driven target vessel revascularisation (4.5% vs. 6.9%; p=0.05).
Dual antiplatelet therapy (DAPT) was prescribed to 274 patients (37.8%) in the angiographic guidance group and 263 patients (36.3%) in the IVUS guidance group (p=0.55), while angiographic follow-up was completed in 488 patients (67.4%) in the angiography group and 507 patients (70%) in the IVUS group at three years after the index procedure (p=0.28).
Gao and colleagues write: “Prespecified subgroup analysis revealed a consistently lower three-year rate of TVF [target vessel failure] in the IVUS guidance group across numerous subgroups, with a tendency for patients with ACS, chronic kidney disease, multivessel disease, type B2/C lesions, or bifurcation lesions to possibly benefit from IVUS guidance. Post hoc analysis suggested that IVUS guidance provided greater benefit in complex PCI [percutaneous coronary intervention], although no interaction existed. Lesion-level analysis showed that the three-year rate of clinically-driven TLR [target lesion revascularisation] or definite stent thrombosis in the IVUS guidance group was significantly lower than that in the angiographic guidance group.”
The rate of definite or probable stent thrombosis was recorded as 0.1% in the IVUS-guided group and 1.1% in the angiography-guided group (p=0.02). Notably, the IVUS-defined optimal procedure was associated with a significant reduction in three-year target vessel failure relative to that with the suboptimal procedure, they add.
Discussing the findings, Gao and colleagues write that the study shows that IVUS-guided optimal drug-eluting stent deployment could provide long-term clinical benefit over a suboptimal procedure.
“The present study demonstrated that the reduction of TVF with IVUS guidance was sustainable and became more significant throughout the three-year clinical follow-up period,” the study team writes. “Notably, we found that patients with IVUS-defined optimal PCI had better clinical outcomes than those who underwent non-optimal IVUS.”
In the view of evidence of this and other randomised trials, they add, “it is time to overcome the barriers, including cost, availability, expertise, and procedure prolongation, to promote IVUS use in daily clinical practice”.
