Bioresorbable magnesium scaffold in the treatment of simple coronary bifurcation lesions: The BIFSORB pilot II study

OBJECTIVES: To evaluate the feasibility, safety, and healing response of a magnesium‐based bioresorbable scaffold (BRS) in the treatment of simple bifurcation lesions using the single stent provisional technique. BACKGROUND: BRS may hold potential advantages in the treatment of coronary bifurcation lesions, however low radial strength and expansion capacity has been an issue with polymer‐based scaffolds. The magnesium BRS may prove suitable for bifurcation treatment as its mechanical properties are closer to those of permanent metallic drug‐eluting stents. METHODS: The study was a proof‐of‐concept study with planned inclusion of 20 patients with stable angina pectoris and a bifurcation lesion involving a large side branch (SB) > 2.5 mm with less than 50% diameter stenosis. Procedure and healing response were evaluated by optical coherence tomography (OCT). The main endpoints were a composite clinical safety endpoint and an OCT healing index at 1 month (range: 0–98). RESULTS: Eleven patients were included in the study. The study was prematurely terminated due to scaffold fractures and embolization of scaffold fragments in three cases requiring bailout stenting with drug‐eluting stents. One patient underwent bypass surgery at 3 months due to stenosis proximal to the study segment. All SB were patent for 1 month. One‐month OCT evaluation showed strut coverage of 96.9% and no malapposition. Scaffold fractures and uncovered jailing struts resulted in a less favorable mean OCT healing index score of 10.4 ± 9.0. CONCLUSIONS: Implanting a magnesium scaffold by the provisional technique in nontrue bifurcation lesions was associated with scaffold fracture, embolization of scaffold fragments, and a high need for bailout stenting.