Intravascular lithotripsy versus scoring balloon for lesion preparation in underexpanded calcified in-stent restenosis treated with drug-coated balloon: an IVUS analysis

Background Management of calcified in-stent restenosis (ISR) with stent underexpansion remains challenging. Calcification within the stent and persistent stent underexpansion often hinder achieving adequate lumen area with conventional balloon angioplasty alone. In recent years, intravascular lithotripsy (IVL) has demonstrated both efficacy and safety as a lesion preparation strategy for calcified coronary lesions. Accordingly, IVL may represent a promising therapeutic option for recurrent ISR, particularly in cases associated with neoatherosclerosis-related calcification or extrastent calcification contributing to stent underexpansion. In this study, we compared IVL with conventional scoring balloon angioplasty for lesion preparation prior to drug-coated balloon (DCB) treatment using intravascular ultrasound (IVUS) analysis. Methods Between 2018 and 2025, 227 ISR lesions were identified. Lesions were included as following criteria: (1) final treatment with a DCB; (2) availability of pre- and post-procedural IVUS for quantitative analysis; (3) presence of calcification within the stented segment; and (4) evidence of stent underexpansion. A total of 54 lesions fulfilled these criteria. Patients were divided into 2 groups based on lesion preparation strategy: the IVL group (n=27) received intravascular lithotripsy prior to DCB treatment, while the conventional group (n=27) underwent predilation with a scoring balloon followed by DCB. The primary endpoints were final minimum lesion area (MLA) and minimum stent area (MSA) assessed by IVUS. Additional IVUS parameters included presence of calcium nodules, maximum calcium arc, and degree of neointimal hyperplasia. Results The mean age was 76.6 ± 9.4 years. Diabetes mellitus was present in 56%, chronic kidney disease in 63%, and 30% were on hemodialysis. The mean DCB diameter and length were 3.13 ± 0.30 mm and 27.2 ± 15.8 mm, respectively. Pre-procedural IVUS findings were comparable between the IVL and conventional groups. Pre-PCI MLA was 2.46 ± 0.86 mm² vs. 2.71 ± 0.75 mm² (p = 0.27), and MSA was 6.39 ± 2.82 mm² vs. 6.70 ± 1.91 mm² (p = 0.64). Maximum calcium arc within the stent was also similar (167.2 ± 133.4° vs. 166.4 ± 98.2°, p = 0.98). Post-procedural IVUS demonstrated significantly greater luminal and stent expansion in the IVL group compared with the conventional group. Final MLA was 6.49 ± 1.80 mm² vs. 4.75 ± 1.22 mm² (p = 0.0001), and final MSA was 9.76 ± 3.29 mm² vs. 7.90 ± 2.27 mm² (p = 0.02). Post-PCI IVUS findings stratified by maximum calcium arc are presented in the figure. Conclusions This study assessed the impact of IVL versus scoring balloon angioplasty for lesion preparation in calcified, underexpanded ISR treated with DCB. The results indicate that IVL achieves superior stent expansion and greater luminal gain compared with conventional techniques. Notably, the advantages of IVL are particularly pronounced in lesions with more extensive calcification.