Sandi Harris, Mercer University College of Pharmacy
A meta-analysis of 10 randomized, controlled trials concluded that drug eluting stents have consistently improved the safety and efficacy of percutaneous coronary intervention as compared with bare metal stents. It is stated that very late stent thrombosis still occurs with drug eluting stents, especially with first generation devices. 
American College of Cardiology Foundation/American Heart Association guidelines indicate that clopidogrel should be used for one to twelve months with bare metal stents (BMS) and for at least 12 months with a drug eluting stent (DES). 
Title: Prolonged Clopidogrel Use is Associated with Improved Clinical Outcomes Following Drug-Eluting, But Not Bare Metal Stent Implantation
|Design||Retrospective, linkage study; N= 15,629|
|Objective||To evaluate the effect on mortality of continuing clopidogrel beyond 12 months in patients who have undergone a PCI and received a DES or BMS|
|Study Groups||Patients filling prescriptions for 12 months or less (n= 2,151) were compared with patients filling prescriptions beyond 12 months (n= 1,326) for patients treated with at least one DES. Patients treated with BMS alone were used as a comparator (clopidogrel <12 months, n = 9,301, clopidogrel <12 months, n=2,121). Patients receiving both DES and BMS (n= 153) were included in the DES cohort.|
|Methods||A series of analyses were performed with the period of follow-up starting 12 months from the index coronary intervention. The study sample was stratified by index stent type (BMS vs. DES), and outcomes for patients prescribed clopidogrel for ≤12 months were compared with those filling prescriptions for clopidogrel beyond 12 months from the index coronary stent implantation.|
|Primary Outcome Measure||All-cause mortality|
|Baseline Characteristics|| DES
≤12 months (n = 2,273)
>12 months (n = 1,326)
≤12 months (n = 9,909)
>12 months (n = 2,121)
|Age, years||63 ± 12||64 ± 11||65 ± 12||67 ± 12|
|Male||1,634 (72 %)||957 (72 %)||7,311 (74 %)||1,486 (70 %)|
|Non ST segment elevated
myocardial infarction (NSTEMI)-acute coronary syndrome
|ST segment elevated
myocardial infarction (STEMI)-
|Results||Use of clopidogrel > 12 months was associated with an adjusted hazard ratio of 0.66 (95% confidence interval (CI) 0.45-0.97)|
|Adverse Events||Common Adverse Events: N/A|
|Serious Adverse Events: N/A|
|Percentage that Discontinued due to Adverse Events: N/A|
|Study Author Conclusions||Findings support the use of clopidogrel beyond 12 months in patients treated with first-generation DES, but not in those receiving BMS.|
This study is powered to show that extending the duration of therapy of clopidogrel used by patients who have received a DES beyond one year improves all-cause mortality. Patients who received a BMS do not share this benefit.
- Navarese EP, Andreotti F, Schulze V, et al. Optimal duration of dual antiplatelet therapy after percutaneous coronary intervention with drug eluting stents: meta-analysis of randomised controlled trials. BMJ. 2015;350.
- Wright RS, Anderson JL, Adams CD, et al: 2011 ACCF/AHA Focused Update of the Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction (Updating the 2007 Guideline) A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2011.
- Cruden NL, Din JN, Janssen C, Klinke WP, Smith R, Carere RG, Hilton JD, Siega AD, Robinson SD. Prolonged Clopidogrel Use is Associated with Improved Clinical Outcomes Following Drug-Eluting But Not Bare Metal Stent Implantation. Am J Cardiovasc Drugs. 2016 Jan 9.