Background: Prior to the introduction of drug-eluting stents (DES), diffuse coronary in-stent restenosis (ISR) was mainly treated by brachytherapy (BT), with good short-term and mid-term results. However, there exist limited data on the long-term effects of BT that justify its continuous use.
Materials and methods: Two hundred patients with diffuse ISR treated with intravascular BT were retrospectively followed over 4 years. Group A (n=134) was treated with the noncentered (90)Sr/Y BetaCath radiation system, whereas Group B (n=66) was treated with the centered 32P Galileo source wire system. Primary endpoints after 4 years were target lesion restenosis (TLS) and target lesion revascularization (TLR). Secondary endpoints were target vessel revascularization (TVR) and nontarget vessel revascularization (NTVR), as well as major adverse cardiac events (MACE).
Results: Follow-up at 4 years yielded a TLS rate of 37.6% (Group A, 40.8%; Group B, 31.1%; P=.48). TLR was performed in 34.8% of patients (37.5% in Group A vs. 29.5% in Group B; P=.55). Ten percent of patients underwent coronary bypass surgery. Percutaneous coronary intervention was performed more often in Group A (27.5%) than in Group B (19.7%), while TVR was less frequent in Group A (10.0%) than in Group B (18.0%). NTVR was undertaken in 25.0% of Group A patients versus 21.3% of Group B patients, and MACE occurred in 1.7% of Group A patients versus 3.3% of Group B patients. These differences were not statistically significant (P>.05).
Conclusions: While excellent short-term and mid-term results after coronary BT are widely accepted, a high TLS rate can be observed after 4 years. The potential superiority of DES to BT will depend on the availability of long-term clinical data.