Long-term outcomes of drug-eluting versus bare-metal stent implantation in patients with chronic total coronary artery occlusions

Background There are limited data on the efficacy of drug-eluting stents (DES) for treatment of chronic total occlusions (CTO). The aim of the study was to evaluate the long-term clinical outcomes of DES implantation for CTO compared with bare-metal stent (BMS) implantation.Methods Between June 1995 and December 2006, a total of 1184 patients with successful recanalization of at least one de novo CTO lesion were consecutively registered, including 660 (55.7%) who underwent DES and 524 (44.3%) who underwent BMS implantation. All patients were followed up for up to 5 years for occurrence of major adverse cardiac events (MACE). Long-term survival rates were estimated with the Kaplan-Meier method.Results Baseline clinical and angiographic characteristics were comparable between the two groups except that patients in the DES group received longer dual antiplatelet therapy ((7.4±2.5) months vs (1.7±0.8) months, P<0.001). Average follow-up periods were (4.7±0.89) and (3.2±1.3) years for the BMS and DES groups, respectively. There was no significant difference in 5-year survival rates between the two groups (90.3% for DES group vs 89.6% for BMS group, Log-rank P=0.38), but the 5-year target vessel revascularization (TVR)-free survival rate in the DES group was significantly higher than that in the BMS group (81.6% vs 73.5%, Log-rank P <0.001). The cumulative MACE-free survival in the DES group was also significantly higher than that in the BMS group (80.6% vs 71.5%, Log-rank P <0.001). The rates of re-admission caused by cardiovascular disease (27.0% vs 37.8%, P <0.001) and the need for bypass surgery were significantly lower in the DES group (1.5% vs 3.4%, P <0.05). By multivariable analysis, DES implantation could significantly lower the long-term MACE risk of PCI for CTO patients (HR: 0.492; 95% CI 0.396-0.656, P <0.001). Left ventricular ejection fraction <50% and elderly (>65 years) were identified as independent predictors of long-term MACE during follow-up.Conclusion This study demonstrates the long-term (up to 5 years) efficacy of DES for treatment of CTO, which is superior to BMS implantation in reducing the rates of FVR and MACE, as well as the need of re-admission and bypass surgery.