Longer Use of Clopidogrel Improves Stent Outcomes

A new VA study supports longer durations of dual antiplatelet therapy for cardiovascular patients receiving a stent, especially those receiving a drug-eluting stent.

Researchers from the Veterans Affairs Boston Healthcare System embarked on the study because, while current guidelines recommend combining clopidogrel, marketed as Plavix, with aspirin for up to one year after coronary stenting, the value of clopidogrel beyond that time was unclear.

For the studies, all patients in the VA healthcare system receiving either drug-eluting or bare metal stents from 2002 to 2006 were evaluated. The VA’s National Patient Care and Pharmacy databases were used to determine patient characteristics, duration of clopidogrel use and outcomes for as long as four years after the index procedure.

Using Cox proportional hazards to estimate hazard ratios for death, myocardial infarction, revascularization and bleeding from a 12-month landmark after stenting that excluded patients with events within the first 12 months, researchers found that 29,175 of 42,254 patients met the study inclusion criteria.

Clopidogrel administration for more than a year was associated with a lower adjusted risk of death for both drug-eluting stents (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.61, 0.82; P<0.01) and bare metal stents (HR, 0.85; 95% CI, 0.76, 0.96; P=0.01) compared with use of the drug for less than a year. Death and myocardial infarction rates also were reduced, but no effect was observed with stroke or major bleeding.

Researchers noted that the effect of prolonged clopidogrel use on death or myocardial infarction was significantly greater among patients receiving drug-eluting (HR, 0.70; 95% CI, 0.64, 0.84) compared with bare metal stents (HR, 0.88; 95% CI, 0.79, 0.98; interaction P=0.024).

1. Faxon D, Lawler E, Young M, Gaziano M, Kinlay S. Prolonged Clopidogrel Use After Bare Metal and Drug-Eluting Stent Placement: The Veterans Administration Drug-Eluting Stent Study. Circ Cardiovasc Interv. 2012 Jun 5. [Epub ahead of print] PubMed PMID: 22668555.