Background: Treatment of in-stent restenosis is still a challenge. Despite promising results obtained with intracoronary brachytherapy (ICB), the ideal strategy of device selection has not been identified. The aim of this study was to evaluate the influence of device selection on ICB for the treatment of instant restenosis.
Methods: The outcomes of 130 patients from the Washington Radiation for In-Stent restenosis Trial (WRIST) were studied. Patients were analyzed on the basis of device selection, prior to randomization to gamma-radiation (n = 65) or placebo (n = 65): balloon angioplasty (PTCA) (n = 15, 12%), rotational atherectomy (RA) (n = 40, 31%), excimer laser coronary angioplasty (ELCA) (n = 28, 22%) or additional stent implantation (n = 47, 36%).
Results: PTCA was less frequently used in lesions with prior in-stent restenosis (14.8%, p < 0.05); ELCA was less frequently used in saphenous vein grafts (57.1%, p < 0.05). The procedural outcomes and restenosis rates were similar among groups. In the RA group, patients assigned or Ir192 had a larger minimal lumen diameter (1.6 +/- 0.5 vs 0.9 +/- 0.4 mm, p < 0.05) and lower diameter stenosis (39 +/- 7 vs 65 +/- 16%, p < 0.05) at follow-up angiography and a reduced late loss (0.2 +/- 0.5 v 0.9 +/- 0.5 mm, P < 0.05) and loss index (0 +/- 0.4 vs 0.8 +/- 0.4, p < 0.05) when compared to placebo. The incidence of delayed thrombosis was 7.7% in the ICB and 4.6% in the placebo group (p = 0.71); additional stenting, either alone (relative risk 12.36, 95% confidence interval 1.56 divided by 94.43) or followed by ICB (relative risk 3.80, 95% confidence interval 1.02 divided by 14.27), was correlated with an increased risk of late thrombosis.
Conclusions: ICB reduces the recurrence of in-stent restenosis through a reduction in late loss. In view of the higher risk of delayed thrombosis, additional stenting, either alone or followed by ICB, should be used with caution.