Prolonged dual antiplatelet therapy unnecessary after stenting
MedWire News: Prolonged antiplatelet therapy is unnecessary for preventing adverse cardiovascular events after stenting and may be harmful, suggest results from the PRODIGY trial.
"While we cannot exclude the possibility that a smaller than previously anticipated benefit may still exist in prolonging therapy with clopidogrel for several months after coronary stenting, our study clearly shows that the benefit to risk ratio of prolonged therapy has been over-emphasized," said Marco Valgimigli from the University Hospital of Ferrara, Italy.
PRODIGY (the PROlonging Dual antiplatelet treatment after Grading stent-induced Intimal hyperplasia studY) was carried out to assess whether current recommendations for treatment with dual antiplatelet therapy (DAPT) for 1 year or more after stenting are justified by improved outcomes.
In total, 1970 patients with acute coronary syndrome (74.5%) or stable coronary artery disease (25.5%) were assigned to treatment with DAPT for 6 or 24 months after stent implantation. Four types of stent - everolimus-, paclitaxel-, or zotarolimus-eluting stents or third-generation thin-strut bare metal stents - were used in a random fashion to ensure that patients in each DAPT group received the same types of stent.
Valgimigli and team report that the risk for the composite endpoint of all-cause mortality, nonfatal myocardial infarction, cerebrovascular accident, or stent thrombosis did not differ significantly between the two DAPT groups, with rates of 10.0% and 10.1% among patients treated for 6 and 24 months, respectively.
However, patients in the 24-month DAPT group had a 2.17-fold greater risk for type II, III, or V Bleeding Academic Research Consortium (BARC) classification events and had a 1.78-fold higher risk for type V or III BARC bleeding events than those in the 6-month DAPT group.
The risks for Thrombolysis in Myocardial Infarction (TIMI)-defined major bleeding and red blood cell transfusion were also significantly greater in the 24-month than the 6-month DAPT group.
"While a formal economic analysis will follow, the results of this study have important implications for healthcare expenditure - for this study shows that prolonging therapy with clopidogrel beyond 6 months is not only associated with no clinical benefit but also with a significant increase in actionable bleeding events requiring rehospitalizations and multiple diagnostic and therapeutic resources," said Valgimigli.
Commenting on the results, discussant Adnan Kastrati (Technische Universität, Munich, Germany) added: "Although we are still waiting for the results of larger trials on optimal duration of DAPT after drug eluting stent implantation, the PRODIGY trial represents one more victory against the greatest enemy of drug eluting stent: the wrongly assumed need for endless DAPT."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Helen Albert