Late and very late catch-up after ⁹⁰Sr/⁹⁰Y beta-irradiation for the treatment of coronary in-stent restenosis

Abstract

Since late vessel failure has been speculated as a significant limitation of vascular brachytherapy (VBT), we conducted a prospective clinical evaluation at 6, 12, 24, 36 and 60 months follow-up after irradiation with ⁹⁰Sr/⁹⁰Y for in-stent restenosis (ISR) regardless of the patient's symptomatic status. Complete five-year follow-up is reported for 104 consecutive patients. The cumulative rate of death was 13.5% (6 months: 0.96%; 12 months: 2.88%; 24 months: 4.81%; 36 months: 7.69%), of acute myocardial infarction 4.81% (2.88%; 4.81%; 4.81%; 4.81%), of late thrombotic occlusion 4.81% (3.85%; 4.81%; 4.81%; 4.81%), of target lesion revascularization (TLR) 27.9% (8.65%; 12.5%; 17.3%; 21.2%), of target vessel revascularization (TVR) 43.3% (12.5%; 19.2%; 22.1%; 29.8%), and of all major adverse cardiovascular events (MACE) 61.5% (16.3%; 26.9%; 31.7%; 42.3%), respectively. Considered that the annual incidence of TVR after the first year following drug-eluting stenting for in-stent restenosis has been reported as approximately 3% per year, an incidence of 5.8% per year following VBT of our study population clearly indicates a more pronounced, delayed and, even in the fifth year after the index procedure, ongoing restenotic process following beta-irradiation of in-stent restenotic |lesions associated with clinically relevant adverse cardiovascular events.

Keywords::

• Restenosis
• PCI
• long-term clinical outcome
• coronary brachytherapy

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.