News:Drug Eluting Stents are Associated with Reduced Mortality Compared with Bare Metal Stents

September 16, 2008 By Vijayalakshmi Kunadian MBBS MD MRCP [mailto:vkunadian@perfuse.org]

The occurrence of late stent thrombosis has raised concerns about the safety of drug eluting stents (DES). In a recent study published in JACC, investigators from Cleveland clinic determined if the slightly higher incidence of late stent thrombosis associated with the DES translated into increased long-term mortality after adjustment for differences in baseline demographic features, angiographic variables, socioeconomic status, cancer, depression, hematocrit levels, creatinine, white blood cell count, and other confounders.

This study consisted of all comers who underwent percutaneous coronary intervention (PCI) at Cleveland Clinic using DES and bare metal stents (BMS) between March 2003 and June 2007 with 4 year follow-up results available. The primary endpoint of this trial was all-cause mortality assessed by querying the Social Security Death Index. A total of 8,036 patients were included in the analysis with 6,053 patients who underwent PCI using DES and 1,983 patients who underwent PCI using BMS. Patients who underwent PCI with BMS had more comorbidities compared with those who received DES.

For the overall population, the rate of death was significantly reduced among those who had DES compared with those who had BMS [8% vs. 17%; HR 0.62 (0.53 to 0.73), p<0.001]. This reduced mortality was observed for each consecutive year. Likewise, the overall propensity-matched analysis demonstrated that DES significantly reduced mortality [10% vs. 16%; HR 0.54 (0.45 to 0.66), p<0.001]. Further analysis which consisted of patients receiving stents from March 2003 to May 2005, from June 2005 to June 2007, those who received stents with diameters <2.5mm, <3.5mm and stents diameter >3.5mm demonstrated similar results that DES was associated with reduced mortality.

Other analysis on pre-specified subgroups such as excluding acute myocardial infarction, excluding vein grafts, excluding death within first 6-months, excluding death within first year and diabetes among non-propensity and propensity matched patients demonstrated that DES significantly reduced death compared with BMS.

The investigators concluded that DES was associated with lower mortality compared with bare metal stents in the “real world” setting. Although the investigators adjusted for several adjustments, potential confounding factors may still play a role.

This study has limitations due to the fact that it is a single center observational study. However, the investigators provide a thorough mortality analysis of a relatively large sample size with longer follow-up following DES and BMS implantation.