Dilcher Christian, Satler Lowell F, Pichard Augusto D, Kent Kenneth M, Porrazzo Michael, Chan Rosanna, Torguson Rebecca, Canos Daniel A, Waksman Ron
Division of Cardiology, Washington Hospital Center, Washington, DC, USA.
Cardiovasc Revasc Med. 2005 Apr-Jun;6(2):52-7. doi: 10.1016/j.carrev.2005.03.002.
Intracoronary beta-radiation therapy reduces in-stent restenosis (ISR). We aimed to determine the safety and feasibility of intracoronary radiation therapy (IRT) utilizing tungsten (188W), a beta emitter.
A total of 30 patients with angiographic evidence of ISR in a previously treated native coronary artery underwent percutaneous coronary intervention (PCI; balloon angioplasty, ablation by atherectomy, or laser angioplasty). After the intervention, a noncentered delivery catheter with a side guide 0.014-in. wire carrying a tungsten (188W) coil, with an active length of 33 mm, was inserted. Patients were randomized to a radiation dose of 18, 22, or 25 Gy at 2 mm from the center of the source. Aspirin and Plavix, at 300 mg loading dose, were administered prior to intervention. Plavix 75 mg/day was prescribed for 6 months after the procedure.
At 6 months follow-up, the overall binary angiographic restenosis rate was 18.8%. Target vessel revascularization (TVR) was 23% and target lesion revascularization related major adverse cardiac events (TLR-MACE) was 13.3%, without any intergroup differences. A comparison with the original Washington Radiation for In-stent restenosis Trial (WRIST) radiation cohort utilizing an 192Iridium source (prescription dose 15 Gy at 2 mm from the source) showed similar TVR and TLR-MACE rates of 30% and 18%, respectively. The TVR and TLR-MACE rates in the WRIST placebo cohort were 70% and 66%, respectively.
Vascular brachytherapy with tungsten (188W) is feasible and safe. The 6-month clinical outcomes are similar to the original WRIST radiation group.