Efficacy Over Time With Drug-Eluting Stents in Saphenous Vein Graft Lesions

In the ISAR-CABG (Is Drug-Eluting-Stenting Associated with Improved Results in Coronary Artery Bypass Grafts?) trial, clinical outcomes at 1 year in patients undergoing treatment of saphenous vein graft lesions were superior with drug-eluting stents (DES) versus bare-metal stents.

The authors compared outcomes between treatment groups at 5 years.

Patients were randomized (1:1:1:3) to receive DES (either permanent-polymer paclitaxel-eluting stents, permanent-polymer sirolimus-eluting stents, or biodegradable-polymer sirolimus-eluting stents) or bare-metal stents. The primary endpoint was the combined incidence of death, myocardial infarction (MI), or target lesion revascularization (TLR). Secondary endpoints were the composite of death or MI and TLR.

A total of 610 patients were allocated to treatment with DES (n = 303) or bare-metal stents (n = 307). At 5 years, the primary endpoint occurred in 159 (55.5%) versus 157 (53.6%) patients in the DES and bare-metal stent groups, respectively (hazard ratio [HR]: 0.98; 95% confidence interval [CI]: 0.79 to 1.23; p = 0.89). There was interaction between treatment effect and time (p_interaction = 0.005), with a lower event rate in the DES group at 1 year (HR: 0.64; 95% CI: 0.44 to 0.94; p = 0.02) but a numerically higher rate between 1 and 5 years (HR: 1.24; 95% CI: 0.94 to 1.63; p = 0.13). Death or MI occurred in 93 (32.8%) versus 108 (36.6%) patients, respectively (HR: 0.85; 95% CI: 0.64 to 1.12; p = 0.24), without significant interaction between treatment effect and time (p_interaction = 0.57). TLR occurred in 84 (33.1%) versus 69 (25.5%) patients in the DES and bare-metal stent groups, respectively (HR: 1.20; 95% CI: 0.87 to 1.64; p = 0.27). There was interaction between treatment effect and time (p_interaction <0.001): TLR was significantly lower in the DES group at 1 year (HR: 0.49; 95% CI: 0.28 to 0.86; p = 0.01) but significantly higher thereafter (HR: 2.02; 95% CI: 1.32 to 3.08; p = 0.001).

In patients undergoing treatment of saphenous vein graft lesions, the advantage of DES over bare-metal stents demonstrated at 1 year was lost at 5 years due to higher attrition of efficacy in the DES group. (Efficacy Study of Drug-Eluting and Bare Metal Stents in Bypass Graft Lesions [ISAR-CABG]; NCT00611910).