Comparison of Two Treatments for Multivessel Coronary Artery Disease in Individuals With Diabetes (FREEDOM)

The purpose of this study is to compare 5-year mortality rates in diabetic individuals with multivessel coronary artery disease (CAD) who undergo either coronary artery bypass grafting (CABG) surgery or percutaneous coronary stenting.

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.

Eligibility Criteria:
Inclusion Criteria:

* Diabetes mellitus (Type 1 or Type 2), defined according to the American Diabetes Association as either:

  1. presence of classic symptoms of diabetes mellitus with unequivocal elevation of plasma glucose (2-hour post-prandial or random of greater than 200 mg/dL (11mmol/L) or
  2. fasting plasma glucose elevation on more than one occasion of at least 126 mg/dL (7mmol/L)
* Currently undergoing pharmacological or non-pharmacological treatment for diabetes
* Angiographically confirmed multivessel CAD \[critical (greater than or equal to 70%) lesions in at least two major epicardial vessels and in at least two separate coronary artery territories (LAD, LCX, RCA)\] amenable to either PCI or CABG
* Angiographic characteristics amendable to both PCI/DES and CABG
* Indication for revascularization based upon symptoms of angina and/or objective evidence of myocardial ischemia

Exclusion Criteria:

* Severe congestive heart failure (class III or IV according to New York Heart Association \[NYHA\] or pulmonary edema)
* Prior CABG surgery
* Prior valve surgery
* Prior PCI with stent implantation within 6 months of study entry
* Stroke within 6 months of study entry; if stroke occurred more than 6 months prior to study entry, must have significant residual neurologic involvement, as reflected in a Rankin Score of greater than 1
* Prior history of significant bleeding (within 6 months of study entry) that may occur during CABG or PCI/DES related anticoagulation
* In-stent restenosis of a target vessel
* Two or more chronic total occlusions in major coronary territories
* Left main stenosis (at least 50% diameter stenosis)
* Acute ST-elevation MI (Q-wave) within 72 hours of study entry requiring revascularization
* Abnormal creatine kinase level (greater than twice the normal limit); or abnormal CK-MB level at study entry
* Planned simultaneous surgical procedure unrelated to coronary revascularization (e.g., valve repair/replacement, aneurysmectomy, carotid endarterectomy, or carotid stent)
* Cannot undergo either CABG or PCI/DES because of a coexisting medical condition
* Significant leukopenia, neutropenia, thrombocytopenia, anemia, or known bleeding diathesis
* Intolerance to aspirin or both clopidogrel and ticlopidine
* Dementia with a score of less than 20 on the Mini Mental Status Examination (MMSE)
* Extra-cardiac illness that is expected to limit survival to less than 5 years (e.g., oxygen-dependent chronic obstructive pulmonary disease, active hepatitis, significant hepatic failure, or severe kidney disease)
* Pregnant
* Currently enrolled in another clinical trial
* Unable to attend required follow-up visits