ABSORB China: BVS achieves noninferiority vs. cobalt-chromium everolimus-eluting stent
SAN FRANCISCO — In a multicenter trial to enable approval of the Absorb bioresorbable vascular scaffold in China, the device was noninferior to a cobalt-chromium everolimus-eluting stent for angiographic in-segment late loss at 1 year.
“ABSORB China met its primary endpoint of noninferiority between Absorb [bioresorbable vascular scaffold] and Xience V for in-segment late loss at 1 year,” Runlin Gao, MD, of the Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Beijing, said in a presentation. “Absorb [bioresorbable vascular scaffold] achieved high rates of acute device and procedural success, similar to Xience V.”
Gao and an international team of researchers randomly assigned 480 patients with one or two de novo native coronary artery lesions at 24 sites to bioresorbable vascular scaffold (BVS; Absorb, Abbott Vascular; n = 241) or cobalt-chromium everolimus-eluting stent (Xience, Abbott Vascular; n = 239).
The investigators stratified the cohort based on diabetes and number of lesions treated and randomly assigned them in a 1:1 ratio. Angiographic and clinical follow-up were scheduled for 1 year in all patients, with in-segment late loss serving as primary endpoint. Results were powered for noninferiority with a margin of 0.15 mm.
Patients treated with bioresorbable scaffold and cobalt-chromium stent experienced comparable acute clinical device success (98% vs. 99.6%; P = .22) and procedural success (97.5% vs. 98.3%; P = .75).
At 1 year, in-segment late loss was 0.19 ± 0.38 mm in patients with bioresorbable scaffold vs. 0.13 ± 0.37 mm in patients with cobalt-chromium stent. With the one-side 97.5% upper confidence limit of the difference 0.14 mm, bioresorbable scaffold achieved noninferiority vs. cobalt-chromium stent (P for noninferiority = .01).
Additionally, bioresorbable scaffold and cobalt-chromium stent showed comparable 1-year rates for target lesion failure, including cardiac death, target vessel MI, ischemia-driven target lesion revascularization (3.4% vs. 4.2%; P = .62), as well as definite/probable scaffold/stent thrombosis (0.4% vs. 0%, respectively, P = 1).
“Long-term results are still ongoing,” Gao said.
Cardiology Today’s Intervention Editorial Board member Gregg W. Stone, MD, TCT co-director and moderator for the session, said the ABSORB China and ABSORB Japan trials are important.
“They brought in routine angiographic follow-up, at 12 and 13 months, respectively … and show overall great suppression of neointima (and) very low late loss with both devices,” he said. “We now have four randomized trials of Absorb vs. Xience with 1-year data.”
TCT founder Martin B. Leon, MD, who also moderated the session, said “the promise of the long-term technology” outweighs the short-term benefits of using the bioresorbable scaffold — although it will take time.
“By 3 years, the device is gone, it leaves no residual material behind,” Leon said. “You potentially will get these benefits from less neoatherosclerosis, less polymer reactions, less stress fractures, unjailing (of) jailed side branches, unjacketing full metal jackets. This is theoretical, and it’s going to take us a good 5-plus years to get the long-term data.” – by Allegra Tiver
Gao R, et al. ABSORB China: A prospective randomized trial of an everolimus-eluting bioresorbable scaffold vs. an everolimus-eluting metallic stent in patients with coronary artery disease. Presented at: TCT Scientific Symposium; Oct. 11-15, 2015; San Francisco.
Disclosure: Gao reports receiving a research grant from Abbott Vascular. Please see the full study for a list of all other authors’ relevant financial disclosures.