APPOSITION V: Self-expanding BMS inferior to balloon-expandable BMS

ORLANDO, Fla. — Mainly due to increased rates of stent thrombosis, a self-expanding bare-metal stent failed to prove noninferiority to a balloon-expandable BMS, according to the results of the APPOSITION V trial.

Researchers compared the self-apposing nitinol BMS deployed by retracting a sheath (Stentys) to a balloon-expandable BMS (Multi-Link, Abbott Vascular) in patients with STEMI. The findings were reported at the Society for Cardiovascular Angiography and Interventions Scientific Sessions.

The trial was to enroll 880 patients but was stopped after enrollment of 303 (mean age, 60 years; 76% men). Only 56 participants were from North America, Roxana Mehran, MD, professor of medicine (cardiology) and population health and policy and director of interventional cardiovascular research and clinical trials at Icahn School of Medicine at Mount Sinai, said during a presentation.

Roxana Mehran

“Enrollment was stopped on July 31, 2014, due to slow enrollment, despite the fact that not one of the investigators were reluctant to place [BMS] in STEMI patients,” Mehran, associate medical editor of Cardiology Today’s Intervention, said. “On Aug. 6, upon full review by the Data Safety Monitoring Committee of all of the data, they also concurred with stopping the study.”

The primary endpoint was target vessel failure at 12 months.

Lesion length was longer in the self-expanding stent group (P = .02) and pre-dilatation was used more often in that group (P = .04), Mehran said. The self-expanding stent group also had more thrombus after the procedure (P = .02).

At 12 months, TVF was greater in the self-expanding stent group, and the noninferiority standard was not met (12% vs. 7.1%; P for noninferiority = .33), she said.

The differences between the groups in cardiac death (1.6% vs. 0%), target vessel recurrent MI (5.3% vs. 2%) and clinically driven target vessel revascularization (11.5% vs. 7.1%) were not statistically significant, but all were higher in the self-expanding stent group, according to the researchers.

A major factor was likely that stent thrombosis occurred in 6.2% of the self-expandable stent group but in only 1% of controls (P = .04), Mehran said.

“Almost all of this was driven by early events of stent thrombosis,” she said. “The review of this revealed moderate to severe underexpansion at the time of stent deployment in 37% of cases. Proximal and distal disease were left untreated in the majority of these patients. About 80% of cases did not achieve satisfactory results as we would be used to.”

Eventually, she said, the sponsor reworked the product into a balloon-expandable, sirolimus-eluting stent. – by Erik Swain

Reference:

Mehran R, et al. Late Breaking Clinical Trials – Part 2. Presented at: Society for Cardiovascular Angiography and Interventions Scientific Sessions; May 4-7, 2016; Orlando, Fla.

Disclosure: The study was funded by STENTYS. Mehran reports receiving institutional research support from AstraZeneca, Bayer, Bristol-Myers Squibb, Eli Lilly/Daiichi Sankyo and The Medicines Company; serving on advisory boards for Abbott, Janssen Pharmaceuticals and Osprey Medical; and receiving consultant fees/honoraria from Medscape.