Effect of optimal lesion preparation prior to implantation of a magnesium-based bioresorbable scaffold: 12-month results of the OPTIMIS study

Background: Lumen reduction after bioresorbable scaffold implantation has been reported. This study aimed to assess the influence of pre-dilatation with a scoring balloon versus a standard non-compliant balloon prior to implanting a magnesium-based Magmaris bioresorbable scaffold (MgBRS) on lumen measurements using optical coherence tomography (OCT) and on clinical outcomes after 12 months. Method: In the OPTIMIS-study (Optimal lesion preparation before implantation of a MgBRS in patients with coronary artery stenosis), patients were randomly assigned to pre-dilatation with a scoring balloon or a standard non-compliant balloon before MgBRS implantation. OCT was performed before and after scaffold implantation, and at 6- and 12-month follow-up. Clinical 12-month follow-up was performed for all 82 enrolled patients. Results: Serial pre- and post-procedural, 6- and 12-month OCT were available in 33 lesions (scoring: n = 16 vs. standard: n = 17). Minimal lumen area (MLA) (scoring 4.6 ± 0.5 mm² vs. standard 3.6 ± 0.5 mm², p = 0.16) did not differ significantly at 12 months. In both the scoring and standard non-compliant balloon group, MLA changed significantly over time (post-procedure – 6-month – 12-month) (scoring balloon: 7.2 ± 1.8 mm²–5.1 ± 1.7 mm²–5.0 ± 1.9 mm², p < 0.01, and standard non-compliant balloon: 6.2 ± 1.1 mm²–5.2 ± 1.5 mm²–5.3 ± 2.0 mm², p < 0.01). No target lesion revascularizations (TLR) occurred in the scoring balloon group, compared to 7 TLR in the standard non-compliant balloon group within 12 months. Conclusion: In lesions treated with MgBRS, MLA did not differ significantly after 12 months among lesions pre-dilated with a scoring balloon compared to a standard non-compliant balloon. However, only lesions pre-dilated with a scoring balloon were free from TLR.