Clinical Outcomes in Patients Undergoing Coronary Brachytherapy for Restenosis of Coronary Vessels Previously Treated With Drug Eluting Stents
Coronary brachytherapy has been shown to be a potential option for patients that require reintervention following in-stent restenosis (ISR) of a drug eluting stent (DES). The purpose of this study is to assess long-term clinical outcomes in patients undergoing coronary brachytherapy with high-dose-rate (HDR) beta radiation after ISR of a DES in native and grafted vessels.
This is a single institution retrospective review of 55 patients that underwent coronary brachytherapy after ISR of a previous DES between January 2015 and June 2017. Each patient underwent cardiac angioplasty with standard percutaneous techniques. A prescribed dose of 23 Gy was delivered to vessels with diameter ≥3.4mm and 18.4Gy in those less < 3.4mm. The primary clinical endpoints were freedom from reintervention and major adverse cardiac events (MACE), defined to be myocardial infarction, progressive congestive heart failure (CHF), or target vessel reintervention.
A total of 61 treated vessels in 55 patients were eligible for analysis with a median follow up time of 49.7 months. No brachytherapy-related complications were observed during the follow up period. Of the 61 vessels, 20 (33%) were grafted and 41 (67%) were native vessels. Overall, there were 29 (48%) patients with ISR requiring reintervention of the previously treated vessel, and 46 (75%) patients that experienced at least one documented MACE. In the graft vessel subgroup, 10 (50%) required reintervention and 15 (75%) experienced a MACE. In the native vessel subgroup, 19 (46%) required reintervention and 31 (51%) experienced a MACE. The overall median times to reintervention and MACE were 11.1 months and 9.1 months, respectively. The median time to a MACE for grafted vessels was 16.8 months compared to 7.0 months in native vessels. The median time to reintervention for grafted vessels was 13.78 months and 8.13 months for native vessels.
Coronary brachytherapy is a suitable treatment modality for patients with recurrent ISR. The current data demonstrates that it is a safe and effective approach in both native and grafted vessels in patients who have failed multiple prior interventions with DES. We observed the freedom from reintervention was longer for grafted vessels compared to native vessels. A similar result was observed in freedom from a MACE. Further prospective studies are needed to validate and expand on these findings.