SAN FRANCISCO – One-year data from the ABSORB III trial and 2-year data from the ABSORB II trial have demonstrated similar outcomes for an everolimus-eluting bioresorbable vascular scaffold (BVS) when compared with a metallic everolimus-eluting stent (EES).
The findings of the 2 trials were presented at the 2015 Transcatheter Cardiovascular Therapeutics (TCT) annual meeting in San Francisco.
For the multicenter, randomized ABSORB III trial, Dean J. Kereiakes, MD, of The Christ Hospital Heart and Vascular Center and the Lindner Research Center at The Christ Hospital in Cincinnati, and colleagues enrolled 2,008 patients with stable or unstable angina.
Patients were randomly assigned 2:1 to receive either an everolimus-eluting BVS (n=1,322; Absorb, Abbott Vascular, Santa Clara, CA) or a cobalt-chromium EES (n=686; Xience, Abbott Vascular, Santa Clara, CA). Similar to drug-eluting stent technology, the BVS facilitates mechanical support and drug delivery; however, after about 1 year, it begins to be absorbed by the body and is eventually completely absorbed after a period of several years.
One-year target-lesion failure—a composite of cardiac death, target-vessel myocardial infarction (MI) or ischemia-driven target-lesion revascularization—served as the study’s primary endpoint, and was tested for both noninferiority and superiority.
At 1 year, the everolimus-eluting BVS was noninferior to the EES with regard to the primary endpoint (BVS, 7.8% vs. EES, 6.1%; noninferiority P=.007; superiority P=.16).
The rates of cardiac death (P=.29), target vessel MI (P=.18) and ischemia-driven target lesion revascularization (P=.5) were also similar between groups, although the study was not powered for clinical endpoints. In addition, the rate of device thrombosis at 1 year was comparable between groups (P=.13).
“The ABSORB III trial has demonstrated safety and efficacy of Absorb BVS at 1 year in patients with stable [coronary artery disease] and stabilized [acute coronary syndrome],” Kereiakes said at a press conference. “Longer-term evaluation is ongoing to determine if Absorb improves late outcomes compared to Xience.”
This longer-term analysis, Kereiakes said, will include the ABSORB IV trial, which is currently planned to enroll 3,000 patients to evaluate BVS vs. EES. The difference in target-lesion failure events will serve as the primary endpoint.
These data from ABSORB IV will be combined with the data from ABSORB III to create a study population of approximately 5,000 U.S. patients.
“[This combined analysis]is the ‘money shot’ to show that there are clinically meaningful differences between these two devices,” Kereiakes said, adding that it will probably take 6 to 7 years before these results become available.
Bernard R. Chevalier, MD, of the Institut Cardiovasculaire Paris Sud, presented results from ABSORB II, which was the first randomized, single blind, active-controlled trial comparing BVS with EES. Patients were randomly assigned 2:1 to either BVS (n=335) or EES (n=166).
Although vasomotion at 3 years was the study’s primary endpoint, for the present analysis Chevalier reported 2-year outcomes, including the patient-oriented composite endpoint (PoCE), defined as all-cause death, MI and revascularization.
According to Chevalier, PoCE was 11.6% in the BVS arm vs. 12.8% in the EES arm (P=.70).
Researchers also reported a trend favoring the EES in the device-oriented composite endpoint/target lesion failure (3% vs. 7%; P=.07), and a similar rate of major adverse cardiac events between the two devices (BVS, 7.6% vs. EES, 4.3%; P=.16). Furthermore, target vessel failure, a composite of cardiac death, MI and clinically indicated target-vessel revascularization, was 8.5% for BVS and 6.7% for EES (P=.48).
“At 2 years, there were no significant differences in the clinical outcomes between the two arms,” Chevalier said at the press conference. “The exploratory observations presented in this report are hypothesis generating and need to be confirmed in larger randomized trials, such as ABSORB III.”
Disclosures: Bernard Chevalier, MD and Dean J. Kereiakes, MD are consultants for Abbott Vascular (Santa Clara, CA).
1. Chevalier BR et al; Kereiakes DJ et al. Late-Breaking Trials and First Report Investigations I. Presented at: 27th Annual Transcatheter Cardiovascular Therapeutics scientific symposium; October 10-15, 2015; San Francisco.
2. Ellis SG et al. Everolimus-Eluting Bioresorbable Scaffolds for Coronary Artery Disease. N Engl J Med. 2015; doi:10.1056/nejmoa1509038.