After six months, patients with coronary artery disease who received the investigational Fantom bioresorbable scaffold had a low risk of major adverse cardiovascular events, according to a prospective, multicenter trial. The device also had low late lumen loss.
Lead researcher Alexandre Abizaid, MD, PhD, presented the findings Oct. 31 in a first report investigations session at the Transcatheter Cardiovascular Therapeutics scientific symposium in Washington, DC.
Reva Medical, which manufactures the sirolimus-eluting Fantom bioresorbable scaffold, funded the study. The device is not yet FDA-approved. The Fantom is the only bioresorbable scaffold that can be identified by x-ray, according to Abizaid, the director of interventional cardiology at the Instituto Dante Pazzanese de Cardiologia in Sao Paolo, Brazil.
“I was concerned that they would not get good angiographic results with such a thin strut,” David J. Cohen, MD, director of cardiovascular research at Saint Luke's Mid America Heart Institute in Kansas City, Missouri, said during a news conference. “The immediate angiographic results are excellent with a residual stenosis of about 7 to 8 percent, which matches what we get with a typical metallic [drug-eluting stent].”
The trial, known as FANTOM II, enrolled 240 patients at 28 centers in eight countries in Latin America and Europe who had 2.5 mm to 3 mm vessels and lesion length of 20 mm or less. The mean age was 62.7 years old, 70.4 percent of patients were males.
At six months, there were five major adverse cardiovascular events: three target vessel MIs, two clinically driven target lesion revascularizations and one cardiac death. The mean late lumen loss was 0.25 mm, which Cohen said was not as low as other drug-eluting stents but was still acceptable.
For the scaffold lumen area, there was a statistically significant 1.1 mm2 mean lumen area reduction and 1.0 mm2 minimal lumen area reduction from baseline through six months. For the stent area, there was a 0.1 mm2 mean lumen area reduction and 0.1 mm2 minimal lumen area reduction, which were not statistically significant. In addition, 98.1 percent of the struts were covered during the follow-up period.
“There was a little bit of uncaging, minimal, but at least we don’t see chronic recoil despite the fact that this is a thinner device,” Abizaid said during a news conference.
Abizaid said there was acute technical success in 95.8 percent of patients, acute procedural success in 99.1 percent of patients and clinical procedure success in 99.6 percent of patients.
The researchers defined acute technical success as successful delivery and deployment of the intended scaffold in the intended lesion without device-related complications. Meanwhile, they defined acute procedural success as acute technical success resulting in a residual stenosis of 50 percent or less with no immediate in-hospital major adverse cardiovascular events. In addition, they defined clinical procedural success as acute procedural success with no major adverse clinical events in the 30 days following the intervention and a final diameter stenosis of 50 percent or less.
The researchers plan on performing serial imaging sub-studies at 24 and 48 months and following the patients for five years.
“The big question will be long-term safety, does it provide any advantage?,” Cohen said. “That’s only going to be answered with long-term follow-up of much larger cohorts. But I think the early signals of the angiographic results and the [optical coherence tomography] are very promising.”