Abstract: Objective This observational study compared the rates of death, myocardial infarction(MI), repeat revascularization and stent thrombosis after implantation of drug eluting stents(DES) versus bare metal stents(BMS) in unselected patients with diabetes mellitus to evaluate the long-term efficacy and safety of DES. Methods We consecutively included 834 diabetic patients who underwent either DES(n=583) or BMS(n=251) in our institution from July 2003 to December 2005. The primary end point was all-cause mortality at 24 months, the secondary end points were the occurrence of nonfatal MI, cerebrovascular events and repeat revascularization and major adverse cardiac events(MACE) at 24 months. Results After adjusting with Cox regression, the risk of mortality in the DES group was significantly lower than that in the BMS group (3.2% vs 5.1%, hazard ratio of DES vs BMS 0.58, 95% confidence interval 0.12 to 0.94, P=0.038), similar outcome had also been found in the adjusted risk of cardiac mortality(2.2% vs 4.4%, HR=0.29, 95% CI: 0.13~0.87, P=0.027) at 24 months, although the adjusted risk of nonfatal MI and the composite of the cardiac mortality and nonfatal MI was similar. DESs was not associated with increased risk of stent thrombosis(2.7% vs 3.2%, HR=0.61, 95% CI: 0.17~1.32, P=0.144). The MACE rate was also lower in the DES group(15.8% vs 27.9%, HR=0.19, 95% CI: 0.09~0.85, P<0.001) due to less mortality and less repeat revascularization with DES(10.5% vs 20.7%, HR=0.24, 95% CI: 0.11~0.78, P<0.001). Conclusion In a real-world diabetic patient population, DES was related to reduced mortality, repeat revascularization and MACE rates at long-term follow-up compared with BMS without increased risk of stent thrombosis, or nonfatal MI. The survival benefits of DES resulted from reducing revascularization procedures for restenosis which could account for the reduction in mortality and MI, higher rate of complete revascularization and no additional risk of stent thrombosis.

Key words: drug eluting stents, bare metal stents, diabetes mellitus, stent thrombosis