Impact of IVUS Guidance on Clinical and Procedural Outcomes in Intracoronary Brachytherapy

BACKGROUND: Intravascular brachytherapy (ICBT) has re-emerged as an effective treatment for in-stent restenosis (ISR). Intravascular ultrasound (IVUS) enables detailed assessment of stent expansion, neointimal proliferation, and other mechanical causes of ISR, potentially allowing more tailored procedural strategies and improved lesion preparation before radiation therapy. OBJECTIVES: The objective of the study was to evaluate the clinical utility of IVUS guidance during ICBT for ISR, with emphasis on long-term clinical outcomes. METHODS: We performed a retrospective analysis of patients undergoing ICBT for ISR between 2016 and 2024. Patients were stratified according IVUS use during the procedure. The primary endpoint was target lesion revascularization at follow-up. Secondary endpoints included all-cause mortality and postprocedural myocardial infarction. RESULTS: A total of 221 patients were included (132/221 [59.7%] IVUS-guided). IVUS use was associated with larger vessel diameter (3.6 ± 0.04 mm vs 3.3 ± 0.05 mm; P < 0.001), advanced lesion preparation (65/132 [49.2%] vs 17/89 [19.1%]; P < 0.001), and longer brachytherapy dwell time (332.2 ± 2.6 s vs 313.4 ± 4.2 s; P < 0.001). At a median follow-up of 717.9 ± 46.1 days, all-cause mortality (11/132 [8.3%] vs 21/89 [23.6%]; P = 0.03) and postprocedural myocardial infarction (15/132 [11.4%] vs 23/89 [25.8%]; P = 0.005) were more frequent in the non-IVUS group. Cox regression analysis showed higher target lesion revascularization in the IVUS group (HR: 1.68; 95% CI: 1.05-2.68; P = 0.03). CONCLUSIONS: IVUS-guided ICBT for ISR was safe but was not independently associated with improved long-term outcomes.