Long-term serial functional evaluation after implantation of the Fantom sirolimus-eluting bioresorbable coronary scaffold.

ABSTRACT

BACKGROUND: Quantitative flow ratio (QFR) has been validated as an accurate surrogate of standard wire-based fractional flow reserve. The clinical and angiographic outcomes of the Fantom sirolimus-eluting bioresorbable coronary scaffold (BRS) have been previously studied and reported. We investigate the functional performance of the Fantom BRS. METHODS: The FANTOM II trial prospectively enrolled 240 patients with stable coronary artery disease or unstable angina, of which 235 patients received the Fantom BRS and were included in the present analysis. We performed an independent serial QFR analysis of the target vessel at baseline, post-percutaneous coronary intervention (PCI), and at 6- or 9-month and 24-month follow-up, using a QFR threshold ≤0.80 to define functional ischemia. RESULTS: QFR was analyzable in 178 patients at baseline, 185 post-PCI, 178 at 6- or 9-month follow-up, and 30 at 24-month follow-up. At baseline, 119 patients (66.9%) had a QFR ≤0.80, whereas 12 (6.5%) post-PCI, 13 (7.3%) at 6- or 9-month follow-up, and 3 (10.0%) at 24-month follow-up had a QFR ≤0.80. QFR improved from baseline to post-PCI, and decreased from post-PCI up to 24-month follow-up. During follow-up period, 28 patients (11.9%) had target vessel revascularization, of which 21 had analyzable QFR and 16 patients (76.1%) had QFR ≤0.80 at the time of revascularization. CONCLUSIONS: Off-line serial QFR assessment demonstrated that around 30% patients did not have functionally significant lesions at baseline and the time with target vessel revascularization. PCI with the Fantom BRS improved functional ischemia with a slight decrease in QFR values over 24 months.