TCT 2016 Investigations Examine Potential of Novel Bioresorbable Stent Technologies

November 7, 2016 — The 28th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium, Oct. 29-Nov. 3 in Washington, D.C., featured a number of first report investigations on novel stents that could become the next generation of bioresorbable stents in patients.

“Bioresorbable stents have the potential to be greatly impactful in the treatment of coronary artery disease, and it is exciting to see these first report investigations of several new and novel stents advancing the technology forward,” said Ajay Kirtane, M.D., SM, a co-director of TCT. He is also director of the cardiac catheterization laboratories at NewYork-Presbyterian Hospital/Columbia University Medical Center and an associate professor of medicine at Columbia University College of Physicians and Surgeons. “These results give us the first insights into their safety and efficacy, but larger randomized trials are necessary in order to establish their role in clinical practice.”

Some of the note-worthy first reports examining bioresorbable stents highlighted at TCT 2016 included:

FANTOM II: Six-Month and Nine-Month Clinical and Angiographic Results With a Radiopaque Desaminotyrosine Polycarbonate-Based Sirolimus-Eluting Bioresorbable Vascular Scaffold in Patients With Coronary Artery Disease
Alexandre Abizaid, M.D., Ph.D.

The FANTOM II study examined the safety and performance of native coronary artery stenting using the radiopaque desaminotyrosine polycarbonate-based sirolimus-eluting bioresorbable vascular scaffold (Fantom). The primary endpoint was the incidence of major adverse cardiac events (MACE) and late lumen loss (LLL) at six months.

The prospective, multicenter trial enrolled a total of 240 patients across 28 clinical centers in eight countries. Patients were sequentially enrolled into two separate cohorts in which the only difference between them was a six-month (Cohort A) versus a nine-month angiographic assessment (Cohort B). The Cohort A group included a total of 117 patients and the Cohort B group included 123 patients. At six months, the incidence of MACE in both cohorts was 2.1 percent while the mean LLL in cohort A was 0.25 ± 0.40 mm.

“Results of the FANTOM II trial demonstrate sustained performance and safety through six months of this novel bioresorbable scaffold,” said Alexandre Abizaid, M.D., Ph.D., director, interventional cardiology at the Instituto Dante Pazzanese de Cardiologia in São Paulo, Brazil. “This preliminary clinical data indicates good acute performance, as well as enhanced device deliverability, minimal residual stenosis and acute recoil.”

The FANTOM II trial was funded by Reva Medical Inc. Abizaid reported research grants and consulting fees/honoraria from Abbott Vascular, Boston Scientific, Elixir Medical, Medtronic and REVA Medical.

MeRes-1: Six-Month Clinical, Angiographic, IVUS, and OCT Results With a Thin-Strut PLLA-Based Sirolimus-Eluting Bioresorbable Vascular Scaffold in Patients With Coronary Artery Disease
Ashok Seth, MBBS, FRCP, DSc

Results from the first-in-man study of a novel thin-strut PLLA-based sirolimus-eluting bioresorbable vascular stent (MeRes100) showed that it was both safe and effective with no major adverse cardiac events (MACE) at six months.

The MeRes100 is a low-profile, 100µm thin strut PLLA-based BRS with a unique hybrid design featuring open cells at the center and closed cells at the edges resulting in improved trackability and access to side branches. It also has enhanced visibility with three circumferential radiopaque markers at each end.

In this prospective, multicenter, single arm trial of MeRes100 BRS, a total of 108 patients (116 lesions) were enrolled at 16 Indian sites from May 2015 to April 2016. The primary endpoint was major adverse cardiac events (MACE), a composite of cardiac death, myocardial infarction, ischemia-driven target lesion revascularization (ID-TLR), and ischemia-driven target vessel revascularization (ID-TVR) at six months. The secondary endpoint was scaffold thrombosis at six months. The study found no MACE or stent thrombosis (ST) after the deployment of the scaffold up to six-month follow-up. Quantitative coronary analysis (QCA) data at six months demonstrated very favorable in scaffold late lumen loss of 0.15±0.26mm. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) analysis showed no scaffold recoil and near-complete strut coverage (99.3 percent) with neointima.

“The innovative design of the MeRes100 scaffold developed in India addresses some of the limitations of currently available BRS. The MeRes-1 first-in-man study demonstrates that this new generation thinner strut sirolimus-eluting BRS is safe and effective at six months,” said Ashok Seth, MBBS, FRCP, DSc, chairman of the Fortis Escorts Heart Institute and chairman of the Cardiology Council, Fortis Group of Hospitals in New Delhi, India. “These encouraging results provide the basis for further studies using wider range of length and sizes in more complex and larger patient population moving to a randomized pivotal trial against the second-generation metallic drug-eluting stents (DES) by mid-2017.”

The MeRes-1 trial was funded by Meril Lifesciences, India. Seth reported receiving consulting fees/honoraria from Abbott Vascular and Meril Lifesciences.

FUTURE-I: Six-Month Clinical, Angiographic, IVUS, and OCT Results With a Thin-Strut PLLA-Based Sirolimus-Eluting Bioresorbable Vascular Scaffold in Patients With Coronary Artery Disease
Bo Xu, MBBS

FUTURE-I was a prospective, single-center first-in-man study that sought to assess the feasibility, preliminary safety and effectiveness of a thin-strut (100-125µm) PLLA-based sirolimus-eluting bioresorbable scaffold (Firesorb BRS) in patients with single de novo coronary artery lesions.

Between January and March 2016, a total of 45 patients with 45 target lesions were enrolled. After successful implantations of BRS, the 45 patients were randomized to two different follow-up cohorts in a 2:1 ratio. Thirty patients in cohort 1 were required to undergo angiographic, IVUS, and OCT follow-ups at six and 24 months, respectively; and the others in cohort 2 will undergo imaging follow-ups at 12 and 36 months, respectively. The incidence of the primary endpoint, 30-day target lesion failure, was 0 percent with no scaffold thrombosis. At six months, the patient-oriented composite endpoint (PoCE: all death, all Ml, or any revascularization) in Cohort 1 was 3.3 percent (1). One patient underwent non-target vessel revascularization the day after the index procedure due to NSTEMI. The in-scaffold late loss was 0.15mm, the percentage of late recoil by IVUS was 0.76 percent, and the proportion of covered struts was 98.4 percent, including 100 percent in seven patients by OCT, at six-month follow-up, respectively.

“The six-month clinical, angiographic, IVUS and OCT results of the FUTURE-I study demonstrated the feasibility and preliminary safety and efficacy of the thin-strut PLLA-based sirolimus-eluting Firesorb BRS in the treatment of patients with single de novo coronary lesions,” said Bo Xu, MBBS, director of catheterization laboratories at Fu Wai Hospital in Beijing, China. “Long-term imaging follow-up is needed to provide more information, and a pivotal randomized controlled trial (FUTURE-II) will be initiated soon.”

The FUTURE-I trial was funded by a research grant from MicroPort. Xu reported having no relevant conflicts of interest to disclose.

For more information: www.crf.org/tct