Objectives: We sought to determine whether drug-eluting stents (DES) were associated with improved clinical outcomes compared with bare-metal stents (BMS) among a nationally representative, nonexperimental elderly patient cohort.
Background: Randomized controlled clinical trials comparing DES and BMS for treatment of coronary artery disease indicate that although the use of DES reduces rates of coronary restenosis after percutaneous coronary intervention, it does not reduce the rates of mortality or acute myocardial infarction (AMI). Nevertheless, clinical outcomes of DES in nonexperimental, routine clinical practice are uncertain.
Methods: We assembled a retrospective cohort of elderly Medicare beneficiaries (n = 76,525) who received DES within 9 months after Food and Drug Administration approval of the sirolimus-eluting stent (April 2003 to December 2003). Using propensity score methods, we assembled 2 matched control cohorts who received BMS from July 2002 to March 2003 (historical controls) or from April 2003 to December 2003 (contemporary controls). Patient enrollment and claims records were obtained through December 2005 to ascertain mortality, hospitalization for AMI, and subsequent coronary revascularization.
Results: Receipt of a DES was associated with a significant survival benefit, with an adjusted mortality hazard ratio of 0.83 (95% confidence interval 0.81 to 0.86) compared with contemporary controls, and a hazard ratio of 0.79 (95% confidence interval 0.77 to 0.81) compared with historical controls (control group heterogeneity: p < 0.001). Patients with DES had significantly lower adjusted rates of revascularization procedures within the first 2 years after PCI and lower hospitalization rates for subsequent AMI.
Conclusions: In contrast to clinical trial results, DES receipt was associated with fewer subsequent revascularization procedures, lower rates of hospitalization for AMI, and improved survival among elderly Medicare beneficiaries.