(RxWiki News) For patients with coronary disease, taking medication to prevent blood clots for up to two years provides no additional benefit in avoiding adverse heart events as compared to taking it for six months.
In fact, taking such dual antiplatelet therapy of aspirin and clopidogrel for a prolonged amount of time may increase the risk of hemorrhage, and need for a blood transfusion. The research was highlighted at the European Society of Cardiology's 2011 Congress in Paris.
"Continue with your prescribed therapy unless a doctor suggests otherwise."
Dr Marco Valgimigli, a researcher from the University Hospital of Ferrara in Italy, said the findings have caused him to question the validity of current guideline recommendations, which suggest 12 months of dual antiplatelet therapy after implantation of a drug eluting stent.
He said it is not possible to exclude the possibility that a smaller than previously anticipated benefit may exist with prolonged therapy, but noted that the study clearly indicated that the benefit to risk ratio of prolonged therapy has been overemphasized.
The PROlonging Dual antiplatelet treatment after Grading stent-induced Intimal hyperplasia studY (PRODIGY) was a randomized three-center open-label clinical trial to assess the safety and efficacy or prolonged clopidogrel therapy for up to 24 months in patients with drug-eluting stents.
Drug eluting stents are generally implanted in patients with blood vessel blockages after angioplasty, which involves widening the vessel through a balloon linked to a catheter.
Participants were over the age of 18 with chronic stable coronary artery disease or acute coronary syndromes, including myocardial infarction, a type of heart attack.
More than 2,000 scheduled to receive elective, urgent or emergency coronary angioplasty were randomly assigned to receive one of four types of stents. Types includes third generation thin-strut bare metal, everolimus-eluting stent, paclitaxel-eluting stent and zotarolimus-eluting stent. At 30 days, patients were randomized to receive dual antiplatelet therapy for either six months or 24 months.
Patients that received the long term therapy were found to be at a two-fold greater risk of bleeding events, including major bleeding. Blood transfusions also were needed more frequently among the group who took the therapy for 24 months.
"While a formal economic analysis will follow, the results of this study have important implications for heathcare expenditure -- for this study shows that prolonging therapy with clopidogrel beyond six 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 Dr Valgimigli.