No advantage for Abbott’s Absorb bioresorbable stent
Long-term follow-up of patients treated withe Absorb everolimus-eluting bioresorbable vascular scaffold made by Abbott (NYSE:ABT) showed no clinical advantages compared with the Xience device, according to a pair of trials presented yesterday at TCT 2016.
The 500-patient Absorb II study showed no difference between the devices at 3 years for the co-primary endpoint of vasomotor reactivity, with change in mean lumen diameter of 0.047mm for Absorb and 0.056mm for Xience. Minimum lumen area was 4.32mm2 for Absorb and 5.38mm2 for Xience. The 2nd co-primary endpoint, a composite of death, any myocardial infarction, plus all revascularizations, also showed no difference between the stents.
The mortality rate for the Absorb cohort was 2%, compared with 4% for the Xience group. There were 8 scaffold thromboses in the Absorb group and none in the Xience group.
The 480-patient Absorb China trial, comparing Absorb with the Xience V device, likewise showed similar outcomes for each arm at 2 years. There were no significant differences in a composite endpoint of all-cause death, any MI, or any revascularization (10.1% for Absorb compared with 11.4% for Xience V); or for the composite endpoints of cardiac death, target vessel MI, or target lesion revascularization (4.2% for Absorb, 4.6% for Xience V); major adverse cardiac events (5.1% compared with 5.1%); or target vessel failure (5.5% vs. 6.8%).
The rate of cardiac death was 0.4% for Absorb compared with 1.3% for Xience V and the rate of target vessel MI was 2.1% for Absorb compared with 0.8% for the Xience V stent, according to Medscape.
Simonton told MassDevice.com via an emailed statement that the Absorb II study began 5 years ago when physicians used implant techniques that are no longer used today for Absorb – which has a slightly larger profile than commonly used metallic stents. These techniques, which are in practice today, include preparing the vessel with pre-dilatation angioplasty, appropriately sizing the vessel, and post-dilatation. In a post-hoc analysis in a subset of patients where proper implant techniques were followed, there were no cases of stent thrombosis at 3 years for patients receiving Absorb in the trial.”
“Also presented at the TCT meeting, were analyses from five randomized clinical trials of Absorb (Absorb II, Absorb III, Absorb Extend, Absorb China, Absorb Japan) and the European patient registry trial (Ghost EU) that demonstrate proper implantation technique affects optimal outcomes. As highlighted by FDA advisors in March 2016, and described in the U.S. prescribing label, Absorb, when implanted properly, has comparable short- and long-term results to the best-in-class drug-eluting stent, Xience,” he said in the statement. “Abbott has emphasized implant techniques for Absorb implantation into a revamped training program for physicians globally. In the U.S., where the product was recently approved, Abbott is launching Absorb in a phased way so that physicians undergo a comprehensive training program before they are able to implant Absorb. Upon completion of commercial launch, a post approval patient registry trial in the U.S. will evaluate the clinical safety of Absorb treatment in the real world setting following physician training about proper implantation technique.”