Whilst there has been an increase in the number of coronary artery bypassing graft (CABG) operations performed using internal mammary arteries, the majority are still performed using saphenous vein grafts. These vessels are more prone to occlusion, and treatment of this accounts for a significant proportion of all percutaneous intervention (6%).
The ISAR-CABG (Is Drug-Eluting Stenting Associated With Improved Results in Coronary Artery Bypass Grafts) trial was a large multicentre randomised superiority study that compared clinical outcomes following treatment of de-novo saphenous vein graft lesions with either drug-eluting or bare-metal stents. The primary endpoint was the combined incidence of death, myocardial infarction, and target lesion revascularisation at 1 year.
610 patients with de-novo saphenous vein graft lesions were randomised to receive either drug-eluting or bare-metal stents. The composite primary endpoint incidence was 15% in the drug-eluting stent group (DES) versus 22% in the bare-metal stent group (BMS) (p=0.02). The difference in the composite endpoint was due to a reduction in target lesion revascularisation (7% DES vs. 13% BMS, p=0.01). There was no difference between the groups with respect to all-cause mortality, myocardial infarction, or stent thrombosis. 72% of patients had repeat angiography at a median of 6.7 months which showed restenosis was significantly lower with DES (15% vs. 29%, p<0.0001), with reduced rates of complete graft occlusion (6% vs 12%, p=0.02).
The use of drug-eluting stents for percutaneous intervention to lesions in de-novo saphenous veins grafts is associated with fewer adverse events at 1 year follow-up than bare metal stents, almost entirely due to the reduction in target vessel revascularisation.
Mehilli J, Pache J, Abdel-Wahab M, et al. Drug-eluting versus bare-metal stents in saphenous vein graft lesions (ISAR-CABG): a randomised controlled superiority trial. Lancet 2011; Sep 17;378(9796):1071-8.