Outcomes of intravascular brachytherapy for recurrent drug-eluting in-stent restenosis

Objectives: To examine the outcomes of vascular brachytherapy (VBT) for recurrent drug-eluting stents (DES) in-stent restenosis (ISR). Background: Recurrent DES-ISR can be challenging to treat. VBT has been used with encouraging results. Methods: We report the long-term outcomes of patients with recurrent DES-ISR treated with VBT between January 2014 and September 2018 at a tertiary care institution. The main outcome was target lesion failure (TLF), defined as the composite of clinically driven target lesion revascularization (TLR), target lesion myocardial infarction (MI), and target lesion-related cardiac death. Cox proportional hazards analysis was performed to identify variables associated with recurrent TLF. Results: During the study period, 116 patients (143 lesions) underwent VBT. Median follow-up was 24.7 (14.5–35.4) months. The incidence of TLR, target-lesion MI, and TLF was 18.9%, 5.6%,and 20.1% at 1 year, and 29.4%, 10.5%, and 32.9% at 2 years.Initial presentation with acute coronary syndrome (ACS) was independently associated with TLF (hazard ratio = 1.975, 95% CI [1.120, 3.485], p =.019). Lesions treated with intravascular ultrasound (IVUS) guidance had a lower incidence of TLR (14.3% vs. 39.6%, log-rank p =.038), and a trend toward lower incidence of TLF (19% vs. 42.6%, log-rank p =.086). Conclusions: VBT can improve the treatment of recurrent DES-ISR, but TLF occurs in approximately one in three patients at 2 years. Initial presentation with ACS was associated with higher TLF and the use of IVUS with a trend for lower incidence of TLF.