Safety and efficacy of drug-eluting vs. bare metal stents in patients with diabetes mellitus: long-term follow-up in the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

Patients with diabetes mellitus have more extensive coronary artery disease, more disease progression, and restenosis. The use of drug-eluting stents (DES) in these patients is widespread, despite uncertain long-term safety and efficacy. All consecutive patients with diabetes mellitus in Sweden who underwent percutaneous coronary intervention were entered into the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) during 2003-06 with complete follow-up for 1-4 years (median 2.5). Patients who received at least one DES (n = 4754) were compared with those who received only bare metal stents (BMS) (n = 4956) at the index procedure. Combined outcome of death or myocardial infarction (MI) showed no difference for DES vs. BMS, relative risk (RR), 0.91 [95% confidence interval (CI), 0.77-1.06]. Myocardial infarction was significantly less common with DES in patients who received only one stent RR, 0.80 (95% CI, 0.66-0.96). The restenosis rate was 50% lower in DES-treated patients RR, 0.50 (95% CI, 0.35-0.70) and was associated with a higher adjusted RR of MI, RR, 5.03 (95% CI, 4.25-5.97). DES was associated with reduced restenosis rates in all subgroups of diabetic patients with the greatest benefit in stent diameters < 3 mm or stent length > 20 mm. The number of lesions treated with DES to prevent one restenosis ranged from 11 to 47 in various subgroups. This real-life registry study shows that restenosis was halved by DES in diabetic patients with stable or unstable coronary disease, with similar risk of death or MI up to 4 years compared with BMS.