Use of restenting should be minimized with intracoronary radiation therapy for in-stent restenosis

Restenting at the time of intracoronary radiation therapy (IRT) for in-stent restenosis (ISR) potentially increases the risk of late total occlusion (LTO) of the treated vessel. Prolonged antiplatelet therapy with clopidogrel (6 months) has been shown to be effective in reducing LTO risk. The purpose of this study was to assess the impact of restenting on clinical outcomes following IRT for ISR with 6 months of clopidogrel. We retrospectively evaluated 1,275 patients with 6-months clinical follow-up who were enrolled in radiation trials for ISR using gamma- and beta-emitters conducted at Washington Hospital Center. Patients were analyzed according to whether additional stents were deployed at the time of IRT. The predominant indication for restenting was to optimize the final angiographic result in the event of tissue prolapse or to cover edge dissections. All patients received a minimum of 6 months of clopidogrel. Baseline clinical and angiographic characteristics were similar between the restented and nonrestented groups. Radiation was delivered successfully in all cases. At 6 months, patients treated with additional stents and IRT had a significantly higher rate of target vessel revascularization than patients without additional stents (24.6% vs. 18.7%; P = 0.011). Restenting caused more frequent late thrombosis, late total occlusion, and Q-wave myocardial infarction than no restenting (4.0% vs. 2.2%, P = 0.09; 6.1% vs. 4.3%, P = 0.14; and 1.9% vs. 0.4%, P = 0.009, respectively). Restenting for the treatment of ISR is associated with increased adverse events and should be avoided after intracoronary radiation therapy for in-stent restenosis, as restenting results in a higher recurrence rate and the potential for increased late total occlusion.