BACKGROUND:
The study addresses the critically important problem of how to best revascularize diabetic individuals with multivessel CAD. CAD and diabetes diagnoses are increasing at alarming rates, and much of the information regarding optimal revascularization comes from the Bypass Angioplasty Revascularization Investigation (BARI) study. After five years, data from the BARI study showed 15 excess deaths for every 100 diabetic participants revascularized by percutaneous coronary intervention (PCI) compared to CABG, and at 7 years there were more than 20 deaths. These findings provide compelling evidence for some physicians to conclude that diabetic patients with multivessel disease in need of revascularization are best handled by CABG. But a consensus has not yet been reached because these findings have not been uniformly confirmed by registries and other studies. With the recent introduction of coated stents that significantly reduce or eliminate restenosis, a prevailing belief is that adequate revascularization can be achieved by PCI even in diabetic individuals. New developments in percutaneous techniques should translate to improved prognosis to offset the advantage of CABG seen in the BARI study. Since these new drug eluting stents are not yet approved and are not likely to be on the market for several years, a small window of time exists to gather the evidence to support the strategy that provides optimal revascularization in diabetic individuals.
DESIGN NARRATIVE:
FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease) is a multicenter, two-arm, open label, prospective, randomized superiority trial with equal allocation, of 5 years duration with a minimum of 3 years of follow-up. The main objective of the study is to evaluate whether PCI with drug-eluting stenting (PCI/DES) is more or less effective than the existing standard of care, CABG. The study population will consist of 2,400 adults with diabetes mellitus (Type 1 or Type 2) with angiographically confirmed multivessel CAD and morphology amenable to either PCI or CABG, with indication for revascularization based upon symptoms or angina and/or objective evidence of myocardial ischemia. Patients who consent will be randomized on a 1:1 basis either to CABG or multivessel stenting using drug-eluting stents, and followed at 30 days, 1 year, and then annually for at least 3 years, but up to 5 years. A registry of 2000 patients will also be recruited concurrently, comprised of eligible non-consenting patients for the randomized trial. Eligible patients will be randomized to receive either CABG or multivessel stenting using drug-eluting stents. Patients randomized to the PCI/DES arm will receive, at the discretion of the primary physician or interventionalists, either CYPHER Sirolimus eluting stent (Cordis Corporation, Warren, NJ, USA) or the TAXUS paclitaxel-eluting stent (Boston Scientific Corporation, Natick, MA, USA). However, it is intended that only one type of drug-eluting stent be used in a given patient during the course of the trial. The primary outcome of the study is the composite of all-cause mortality, nonfatal myocardial infarction, and stroke at the end of the 5-year patient accrual and follow-up period (minimum follow-up is 3 years). The main secondary endpoint that will be assessed is the 1-year major adverse cardiac and cerebrovascular event (MACCE) rates, including the first of one of the following: death, myocardial infarction, stroke, or repeat revascularization. Additional secondary endpoints include: all-cause and cardiovascular mortality at 1, 2, and 3 years; rates of individual MACCE endpoints at 30 days post-procedure; quality of life at 30 days, 6 months, and annually post-procedure; long term costs and cost-effectiveness.
