Drug-Eluting versus Bare-Metal Stents in Saphenous Vein Grafts Compared to Native Coronary Vessels: The Norwegian Coronary Stent Trial Study

Abstract

Background: Drug-eluting stents (DES) reduce target lesion revascularization (TLR) with no effect on mortality or myocardial infarction (MI) compared to bare-metal stents (BMS) in native vessels. Randomized stent studies in saphenous vein grafts (SVG) are few and the reported effects are ambiguous. The Norwegian Coronary Stent Trial study is the first to randomize lesions to percutaneous coronary intervention in native vessels and SVG. Aims: The aim of this study was to compare the rate of mortality, MI, and TLR across stent and vessel types. Methods: In this substudy, 6,087 patients with a single lesion in native vessels and 164 in SVG were followed for 5 years. Results: MI was more frequent in SVG (subdistributional hazard ratio [SHR] 4.95 (3.75–6.54, p < 0.001), but not affected by stent type. In the first 500 days, DES reduced TLR in native vessels (SHR 0.21 (0.15–0.30) p < 0.001) and SVG (SHR 0.18 (0.04–0.80) p = 0.02). Thereafter, DES and BMS were equivalent in native vessels, but DES had a higher TLR rate than BMS in SVG (SHR 3.31 (1.23–8.94) p = 0.02). After 5 years, the TLR rate was still significantly lower for DES in native vessels (3.2% vs. 7.8%, p < 0.001) but not in SVG (21.4% vs. 18. 4%). Conclusion: In SVG, no difference in TLR between DES and BMS was observed after 5 years in contrast to persistent benefit in native vessels. The high rate of TLR and MI in SVG makes treatment of native vessels a preference whenever feasible and better treatment options for SVG are warranted.