The question of the appropriate duration of dual anti-platelet therapy (DAPT) for patients getting coronary artery stents has generated almost as much controversy as the late stent thrombosis issue, with the stent makers hewing more or less to their own ideas as to the ideal length of time on DAPT.

At Wednesday's sessions at TCT 2008, participants in a "town hall meeting" hosted by the Department of Health and Human Services unveiled a massive trial that will look at the effect of DATP on as many as 20,000 patients and will likely cost about $100 million, a sum that will be funded by industry. The study — aptly named the Dual Antiplatelet Therapy (DAPT) trial — will review two primary endpoints, stent thrombosis and major adverse cardiac and cerebrovascular events, and the study's sponsors hope to enroll patients by the end of this year with the aim of completing the study by the end of 2012.

The idea of such a trial has been making the rounds since the December 2006 advisory committee meeting during which FDA examined the DES question, and Mitch Krucoff, MD, of the Duke Clinical Research Institute (Durham, North Carolina), filed an investigational device exemption for the CODA (Clopidogrel: Optimal Duration of Antiplatelet Therapy) trial earlier this year.

CODA won no support from industry because the design did not help establish the safety profile of a DES or the effect of DAPT on late stent thrombosis.

Andrew Farb, MD, a medical officer at FDA, told Medical Device Daily that the patients will be on aspirin and either clopidogrel (Plavix) or prasugrel (Effient) for 12 months and then will be randomized either to a placebo or ongoing DAPT for up to 30 months. He acknowledged that given the fears that have surrounded stents and stent thrombosis, "getting patients to consent to randomize may be difficult." Still, there is little choice, he said, because a registry will not answer the questions that have to be answered for DES use.

Farb also said that the Harvard Clinical Research Institute (HCRI; Boston) will conduct the study at a number of centers across the U.S. Laura Mauri, MD, of HCRI is the co-principal investigator along with Dean Kereiakes, MD, of the Linder Research Center at Ohio State University (Columbus). No sites outside the U.S. will participate in the study.

— Mark McCarty, Washington Editor