Comparison of Clinical Outcomes in Patients Undergoing Coronary Intervention with Drug-Eluting Stents or Bare-Metal Stents: A Nationwide Population Study

Abstract

Background: The aim of this propensity score-matched cohort study was to investigate the prognostic impacts of drug-eluting stents (DES) and bare-metal stents (BMS) in patients undergoing percutaneous coronary intervention (PCI).

Methods: We conducted a retrospective cohort study based on the National Health Insurance program. Patients who had undergone coronary stenting between Jan. 2007 and Dec. 2008 were recruited and monitored until the end of 2010. Subjects with either BMS or DES were matched 2:1 by propensity score, which adjusted for age, sex, stent number and Charlson comorbidity index (CCI). The Kaplan-Meier method and Cox regression models were used for prognostic analyses.

Results: Among a total of 966 patients with a mean age of 66 years, 644 subjects had BMS and 322 subjects had DES. The incidence of myocardial infarction (MI) and death were significantly lower in the DES group as compared with the BMS group for the three-year follow-up duration. With adjustments for age, sex, premium-based monthly salary, levels of hospital care, stent number, CCI, medications, and acute coronary syndrome presentation in the index hospitalization, use of DES rather than BMS was associated with reduced adverse coronary events (hazard ratio and 95% confidence interval: 0.55, 0.38-0.81 in the whole population, and 0.44, 0.26-0.73 in the subgroup patients with stable coronary artery disease).

Conclusions: Implantation of DES was related to better outcomes than for BMS, in terms of reducing MI and mortality after PCI. The survival benefit for patients with DES was even greater in patients with stable coronary artery disease.

Keywords: Bare-metal stent; Drug-eluting stent; Propensity score.

Figure 1

The flow chart of patient selection. BMS, bare-metal stents; DES, drug-eluting stents.

Figure 2

Event-free survival analysis of adverse coronary events for patients with bare-metal stent (BMS) or drug-eluting stent (DES) after accounting for age, sex, premium-based monthly salary, levels of hospital care, Charlson comorbidity index, and whether or not acute coronary syndrome at index admission.

Figure 3

Survival analysis for patients with bare-metal stent (BMS) or drug-eluting stent (DES) after accounting for age, sex, premium-based monthly salary, levels of hospital care, Charlson comorbidity index, and whether or not acute coronary syndrome at index admission.