Intravascular brachytherapy for the management of drug-eluting in-stent restenosis.

Objectives: This study aimed to evaluate the utilization and clinical outcomes of coronary intravascular brachytherapy (IVBT) as a treatment modality for multilayer in-stent restenosis (ISR).

Methods: This multicenter study retrospectively analyzed 101 patients who presented for percutaneous intervention of recurrent drug-eluting stent ISR using IVBT from 2019 to 2023. The primary outcome assessed was target lesion revascularization (TLR) at 1 year. Secondary endpoints were aimed to establish procedural safety. All lesions had evaluation by either angiography, intravascular ultrasound, or both.

Results: The majority of ISR was related to neointimal hyperplasia (61.4%), with stent underexpansion (11.9%) being the second most common cause. The average layer of stents in the sample was 1.90 layers. Prior to delivery of IVBT, lesions were prepared with balloon angioplasty, laser atherectomy, intravascular lithotripsy, or a combination of pretreatment strategies. The average time of the IVBT dwell period was 11 minutes, with an average dose of 21.76 Gy. Of the 101 patients evaluated, TLR occurred in 10.9% of patients at 1 year. Readmission at 30 days was 4.9% and vascular complications occurred in 3.9% of the patients. Major adverse cardiac events were limited to 0.9% of the patients, and no peri-procedural myocardial infarctions, urgent need for revascularization within 24 hours, need for mechanical support, nor cardiac arrest were observed.

Conclusions: In this study, IVBT proved to be a safe and effective treatment modality for multilayer ISR. The study generates the hypothesis for the routine use of IVBT in this commonly encountered clinical scenario. Larger and prospective randomized studies are needed.