IntravaScular lithotripsy for the Management of undILatable coronary stEnt: The SMILE Registry

Abstract Background Intravascular lithotripsy (IVL) showed to be effective in dilating heavily calcified de novo coronary lesions but little is known about its performance in under-expanded stents management. Aim of this study was to assess the feasibility, effectiveness and safety of IVL for the treatment of stent underexpansion refractory to balloon dilatation. Methods A multicentre, retrospective cohort analysis was performed in patients undergoing IVL to treat under-expanded stents following non-compliant balloon expansion failure. Primary endpoint was successful IVL dilatation defined as IVL balloon delivery and application at the target site followed by an increase of at least 1 mm2 in minimal stent cross-sectional area (MSA) on intracoronary imaging or an increase of at least 20% in minimal stent diameter (MSD) by quantitative coronary analysis (QCA). Results Thirty-nine under-expanded stents (34 patients) were included. Two cases (5.1%) of multiple stent layers and one (2.5%) acutely under-expanded stent were treated. The median IVL balloon diameter was 3.1 mm (IQR: 2.5–3.5 mm) while the number of pulses emitted was 56.7 (IQR: 30–80). IVL was successful in 34 cases (87.1%), with significant improvement in MSD (post: 3.23 mm [IQR: 3–3.5 mm] vs. pre: 0.81 mm [IQR: 0.35–1.2], p  Conclusions Bailout IVL was feasible, efficacious and safe to improve refractory stent under-expansion.