Use of the Fantom Encore bioresorbable stent (BRS) may reduce the risks associated with permanent implants, with safe and effective clinical outcomes at 5-year follow-up, new data from the FANTOM II trial suggest. The data, presented Wednesday as late-breaking clinical research at EuroPCR 2022 in Paris, reported 5-year follow-up data from the trial, which was set up in 2017 to assess the safety and efficacy of the second-generation Fantom Encore BRS. Presenting the data, lead author Matthias Lutz, MD, from the University Medical Center Schleswig-Holstein, Germany, noted that the Fantom BRS is made from a proprietary bioresorbable polymer known as Tyrocore, which is X-ray visible and has a thin strut thickness of 125 microns. He noted that the data show there is a long-term risk of target lesion failure (TLF) in patients following treatment, with approximately a 2% Increase in TLF rates every year following treatment. “Permanent implants are not needed for a temporary role,” said Lutz, noting that second-generation BRS technologies have the potential to reduce the risks associated with permanent implants. “The vessel is uncaged after 1 year, and the complete result resorption is after 4 years.” Study details The FANTOM II trial was initially designed for CE mark approval for the BRS, with 240 patients in two cohorts across 28 clinical centers. Lutz noted that due to EU regulatory requirements, the two cohorts differed in follow-up duration; while both cohorts were followed for major adverse cardiac events (MACE) for6 months, angiographic follow-up happened at 6 months, with a 2-year sub-study in Group A and at 9 months with a 5-year sub-study in Group B. “We are now on the 5-years follow up, after the 6 or 9 months angiographic-follow up,” he said, adding that baseline data for participants showed an average age of 62 years, with 70% of them male and 24% with diabetes. Around 50% of patients had Type B1 lesions according to American College of Cardiology/American Heart Association Lesion Class, with 18.5% Type A, 29% Type B2, and 2.5% Type C. The overall clinical procedural success rate – defined as acute procedural success, with no MACE 30 days post-intervention and with a final diameter stenosis ≤50 percent – of 99.6%. Lutz revealed 5-year follow-up data showing a MACE rate of 6.3% and target lesion failure (TLF) rate of 5.8%. Within MACE, clinically driven target lesion revascularization occurred in 3.3% of participants, with 1.7% of participants falling under all myocardial infarction events and a further 1.7% cardiac death rate. “If you look to the time course, you can see that in the first year, between 6 and 12 months, we have the big jump where the most events occurred, and after this the curve is more or less flattened,” he noted. “We have no further increase in MACE and target lesion failure rate.” He added that compared to earlier-generation BRS and metallic drug-eluting stents, the second-generation Fantom has significantly better 5-year TLF rates (5.8% Fantom vs. 17.5% Absorb and15.2% Xience, the latter two of which were reported in the ABSORB III trial). The FANTOM II trial was sponsored by REVA Medical, manufacturer of the Fantom Encore BRS.