News | September 08, 2011

Assessing the Most Appropriate Duration of Dual Antiplatelet Therapy After Stenting

September 8, 2011 – A randomized multicenter, open-label study evaluating the efficacy and safety of prolonged antiplatelet therapy in patients with coronary disease has found that 24 months' duration of dual antiplatelet therapy (DAPT) is no better than six months of DAPT in preventing adverse cardiac events. The study results were discussed during the recent European Society of Cardiology (ESC) meeting in Paris, France.

However, the PROlonging Dual antiplatelet treatment after Grading stent-induced Intimal hyperplasia studY (PRODIGY) also found a consistently greater risk of hemorrhage in the 24-month dual therapy group according to all prespecified bleeding definitions, including the recently proposed Bleeding Academic Research Consortium classification. The need for transfusion was also increased in the longer treatment group.

The results, said investigator Marco Valgimigli, M.D., from the University Hospital of Ferrara, Italy, “question the validity of current guideline recommendations –– which were based on registry data –– that at least 12 months' dual antiplatelet therapy should be pursued after implantation of a drug-eluting stent.”

"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 overemphasized," Valgimigli said.
 
The PRODIGY study was a 4-by-2 randomized, three-center open-label clinical trial designed to assess the efficacy and safety of prolonged clopidogrel therapy for up to 24 months in all-comer patients receiving a balanced combination of drug-eluting stents (with various anti-intimal hyperplasia potency and belonging to both first and second generation). Patients were 18 years or older with chronic stable coronary artery disease or acute coronary syndromes, including non-ST-elevation and ST-elevation myocardial infarction.

More than 2000 patients scheduled for elective, urgent or emergency coronary angioplasty were randomly assigned in a 1:1:1:1 fashion to one of four stent types: everolimus-eluting stent, paclitaxel-eluting stent, zotarolimus-eluting stent or third-generation thin-strut bare metal stent. Randomization to the four different types, said Valgimigli, was justified by the different safety profile of each, which was meant to ensure that patients in the two main study groups (six versus 24 month DAPT) received exactly the same stent types. At 30 days, patients in each stent group were then further randomized to either six or 24 months of DAPT.

The primary objective of the study was to assess whether 24-month DAPT, consisting of clopidogrel and aspirin after coronary stenting, was associated with a lower cumulative incidence of all-cause mortality, non-fatal myocardial infarction or cerebrovascular accident (the primary outcome) than six-month dual therapy.

Results showed that the cumulative risk of the primary outcome at two years was 10.1 percent with the 24-month treatment, and 10.0 percent with the six-month (HR 0.98; 95 percent CI 0.74-1.29; P=0.91). The individual risks of death, myocardial infarction, cerebrovascular accident or stent thrombosis did not differ between the two groups. 

Among the patients receiving long-term dual antiplatelet therapy, there was a roughly two-fold greater risk of type 5, 3 or 2 bleeding events (HR 2.17, 95 percent CI 1.44-3.22; p=0.00018) as well as type 5 or 3 bleeding events (HR 1.78, 95 percent CI 1.02-3.13; p=0.037) according to the Bleeding Academic Research Consortium classification. The risks of TIMI-defined major bleeding and red blood cell transfusion were also increased in the 24-month clopidogrel group.

Commenting on the implications of the results, Valgimigli said, "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 re-hospitalisations and multiple diagnostic and therapeutic resources."

For more information: www.escardio.org

Related Content

Lexington Begins HeartSentry Clinical Trial
News | Clinical Study | February 20, 2018
February 20, 2018 – Lexington Biosciences, Inc., a development-stage medical device company, announced the commenceme
Endologix Completes Patient Enrollment in the ELEVATE IDE Clinical Study
News | Clinical Study | February 06, 2018
February 6, 2018 – Endologix, a developer and marketer of treatments for aortic disorders, announced the completion o
12-Month Results from Veryan Medical's MIMICS-2 IDE Study Presented at LINC
News | Clinical Study | February 01, 2018
February 1, 2018 – Thomas Zeller (Bad Krozingen, Germany) presented the 12-month results from Veryan Medical’s MIMICS
LimFlow Completes U.S. Feasibility Study Enrollment, Receives FDA Device Status
News | Clinical Study | February 01, 2018
February 1, 2018 –  LimFlow SA, developer of minimally-inv
ESC 2017 late breaking trial hot line study presentations.
News | Clinical Study | September 12, 2017
September 12, 2017 – The European Society of Cardiology (ESC) Congress 2017 includes several Hot Line Late-breaking C
U.K., NHS studies, weekend effect, hospital admission, atrial fibrillation, heart failure
News | Clinical Study | June 28, 2016
New research shows patients admitted to National Health Service (NHS) hospitals in the United Kingdom for atrial...
stroke risk
News | Clinical Study | August 28, 2015
Most people assume strokes only happen to octogenarians, but recent evidence suggests that survivors of childhood can
Overlay Init