D-38 | Intravascular Brachytherapy for Management of Drug Eluting Stent Restenosis

Historically, intravascular brachytherapy (IVBT) has had mixed results for treatment of in-stent restenosis (ISR) especially in patients with >2 stents. No standard protocol exists for modification of multi-layer ISR at time of IVBT. This study aimed to evaluate rates of target lesion revascularization, periprocedural major adverse cardiac events (MACE), vascular complications, and rehospitalization after introduction of a standard protocol for IVBT for ISR. This single-center study retrospectively analyzed 68 patients from 2020-2023 who underwent IVBT for recurrent drug-eluting stent ISR. The protocol for IVBT included the use of radial or ulnar artery access when feasible, intravascular imaging, laser atherectomy or intravascular lithotripsy, angioplasty with a scoring or cutting balloons, and radiation therapy (21. 65 Gy). The primary outcome assessed was target lesion revascularization within one year. Secondary endpoints were aimed to establish procedural safety, namely, peri-procedural MACE, vascular complications and 30-day readmission. All ISR lesions were evaluated by intravascular ultrasound pre and post modification. The majority of ISR was related to neointimal hyperplasia (70.5%), with stent under-expansion (15.7%) being the second most common cause. The average layer of stents in our sample was 1.89 layers. Of the 68 patients analyzed, target lesion revascularization occurred in 3.6% of patients. Regarding patient safety and secondary outcomes, 30-Day readmission was 4.4% (3 patients) admitted for chest-pain and vascular complications occurred in 2.9% (2 patients) defined as bleeding academic research consortium (BARC) type 2 related to femoral access site complications. MACE was limited to 1.4% (1 patient) due to a procedural complication of coronary artery perforation. We did not observe any peri-procedural myocardial infarctions, urgent revascularization within 24 hours of PCI, need for mechanical support, or cardiac arrest. In our study, protocol-based IVBT was a safe and effective treatment modality for multi-layer ISR. Long-term followup will determine if use of such a protocol can maintain low rates of target lesion revascularization after IVBT.