Clinical Outcomes of Intravascular Brachytherapy for Recurrent In-Stent Restenosis: Is Treatment Failure Predictable?

Area of Science:

• Interventional Cardiology
• Cardiovascular Research
• Medical Device Technology

Background:

• In-stent restenosis (ISR) presents a significant challenge in interventional cardiology with limited effective long-term treatments.
• Intravascular brachytherapy (IVB) is a reemerging treatment option for ISR, but predictors of treatment failure are not well understood.
• This study aims to evaluate clinical outcomes and identify failure predictors for IVB in coronary ISR.

Purpose of the Study:

• To assess the clinical outcomes of intravascular brachytherapy (IVB) for treating in-stent restenosis (ISR).
• To identify patient characteristics and procedural factors predicting response to IVB at one- and three-year follow-ups.
• To investigate the association between stent implantation and long-term mortality after IVB treatment.

Main Methods:

• Retrospective analysis of 199 patients (226 lesions) treated with IVB for coronary ISR from June 2016 to January 2024.
• Stratification of patients based on clinical response at 1 year: responders (no target lesion revascularization [TLR]) vs. nonresponders (TLR present).
• Primary endpoint: TLR at 1 year. Secondary endpoints: major adverse cardiovascular events (MACE), net adverse cardiovascular events (NACE), thrombosis, bleeding, and mortality.

Main Results:

• 82.3% of lesions were responders at 1 year; nonresponders had significantly higher rates of thrombosis, cardiac hospitalization, myocardial infarction, and mortality.
• No baseline or procedural characteristics were significant predictors of TLR in multivariate analysis.
• Stent implantation was associated with increased 3-year all-cause mortality (OR 3.81, 95% CI 1.04-13.99).

Conclusions:

• The majority of patients treated with IVB for ISR experience sustained clinical benefit at one year.
• The link between stent implantation and increased long-term mortality requires further investigation.
• Identifying novel predictors of treatment response is crucial for optimizing patient selection for IVB.