Surface micro-patterned drug-coated balloon enhances early biological efficacy in a porcine coronary in-stent restenosis model.

BACKGROUND: Drug-coated balloon (DCB) therapy for in-stent restenosis (ISR) relies on efficient drug transfer during balloon-artery contact. Surface micro-patterning has been proposed to enhance transfer efficiency without altering the antiproliferative drug. This study evaluated a linear micro-patterned DCB (LMDCB) compared with a comparator paclitaxel-coated DCB in a porcine coronary ISR model. METHODS: ISR was induced by bare-metal stent implantation followed by a 4-week maturation period. In two prespecified cohorts (1 month: 10 animals, 20 segments; 3 months: 4 animals, 8 segments), paired ISR segments within each animal were treated with LMDCB or a comparator paclitaxel-coated DCB (3.0 µg/mm2). Endpoints included quantitative coronary angiography (QCA), optical coherence tomography (OCT), and histology. RESULTS: At 1 month, LMDCB demonstrated a larger minimum lumen diameter (2.3 ± 0.2 mm vs 1.9 ± 0.4 mm; p = 0.019) and lower percent diameter stenosis (13.3 ± 4.8% vs 23.7 ± 9.3%; p = 0.003). OCT showed lower mean neointimal thickness (0.2 ± 0.1 mm vs 0.3 ± 0.1 mm; p = 0.008). Histology showed lower neointimal area (2.4 ± 0.7 mm2 vs 2.9 ± 1.1 mm2; p = 0.011) and percent area stenosis (36.6 ± 10.4% vs 44.4 ± 17.8%; p = 0.013), with comparable vascular healing indices. In the independent 3-month cohort, QCA and OCT findings were similar between groups. Exploratory histology in a limited subset suggested a larger lumen and lower percent area stenosis with LMDCB. CONCLUSIONS: In this porcine coronary ISR model, LMDCB was associated with reduced neointimal proliferation and improved luminal dimensions at 1 month compared with a comparator paclitaxel-coated DCB, without impaired vascular healing. In a separate 3-month cohort, imaging findings were comparable between devices, while histology remained exploratory.