June 8, 2009 - The Bypass Angioplasty Revascularization Investigation With Diabetes Trial (BARI-2D) is a useful and focused trial that builds on the body of scientific knowledge physicians use to provide the best possible care for diabetic patients with chronic stable angina and to evaluate their treatment options, and the Society for Cardiovascular Angiography and Interventions (SCAI) encourages healthcare providers to apply the findings to patients when appropriate.
BARI-2D specifically applies to patients with carefully controlled diabetes, multivessel but stable coronary artery disease (CAD), and few heart disease symptoms. SCAI said multivessel CAD might be better treated with optimal medical therapy (OMT) plus either percutaneous coronary intervention (PCI) or bypass surgery (CABG).
Since the BARI-2D study enrolled a very small subset of CAD patients with diabetes, SCAI said it looks forward to additional data from the upcoming FREEDOM trial, which may shed more light on revascularization options for this growing patient population.
SCAI said BARI-2D demonstrates intensive surveillance of the diabetes patients works. When the blood sugar levels of diabetic patients are controlled to precise levels, as in clinical trials such as BARI-2D, but not so low as to induce hypoglycemia, the result may achieve strong positive outcomes. The goal is to translate these same types of clinical trial results to a real-world patient scenario, where medical therapy compliance is shown to be a large concern.
"It's important to note that in a real-world setting, patients' blood sugar levels are not so closely monitored to maintain optimal levels as in this study," said Robert Chilton, DO, director of the cardiac catheterization laboratory, South Texas VA Medical Center. "The patients I see with diabetes and heart disease frequently have difficulty complying with a drug regimen that includes upwards of 10 pills per day, often coupled with insulin injection. Not surprisingly, noncompliance can quickly lead to deteriorating health and should be carefully considered for patients who may be candidates for revascularization."
Drug-eluting stents (DES) are the standard of care for diabetic patients undergoing angioplasty and stenting. SCAI said DES are imperative for most diabetic patients who require angioplasty. Many patients enrolled in the revascularization/PCI arm of BARI-2D received bare metal stents because DES were not available in the early years of this trial.
Diabetes patients must be screened for CAD, SCAI said. Many diabetic patients may not exhibit symptoms such as chest pain or shortness of breath. However, patients with type 2 diabetes mellitus and CAD are at high risk for cardiovascular events, including heart attack. According to the American Diabetes Association, diabetes affects nearly 24 million people in the U.S., and more than 65 percent die from heart disease or stroke.
"People with diabetes and the physicians who treat them need to be aware of the crucial importance of cardiovascular disease screening, even in relatively healthy patients with no symptoms," Chilton said. "This study is important because it emphasizes the strong tie between diabetes and heart disease, but does not replace the need for physicians to continue to evaluate the individual needs of each patient."
SCAI said there are limitations to BARI-2D. When evaluating patients for inclusion in the two trial arms of BARI-2D, OMT alone or OMT plus revascularization – all patients received an angiogram to determine the type and severity of blockage(s) in the arteries. SCAI stressed this is an important point to understand – it is these sicker patients, who did not meet the inclusion criteria for the trial based on the diagnostic angiogram, who receive the greatest life-saving benefits from revascularization. Since the patients studied in BARI-2D faced only a small risk of death or heart attack to begin with, it stands to reason that revascularization would not show significant mortality benefits, SCAI said.
Findings from the study are not applicable for every patient population, SCAI said. The BARI-2D trial set out to evaluate whether OMT alone or OMT plus revascularization is better in preventing death and heart attacks in a small, relatively healthy subset of diabetic patients with heart disease. The medical guidelines have never suggested PCI could achieve the life-saving benefits for the "healthier" patients as studied in BARI-2D. The trial's findings, while important, apply only to a narrow group of patients, and should not be generalized across broad groups of cardiovascular patients, SCAI said.
"Physicians should understand the patients in the BARI-2D study are highly selected and represent only a very small slice of diabetes and heart disease patients. More research is needed on the larger diabetic population," said Steven R. Bailey, SCAI president and chief of the division of cardiology at the University of Texas Health Sciences Center at San Antonio. "Unfortunately, the majority of the BARI-2D patients did not receive drug-eluting stents, which have been shown to be superior to bare metal stents for diabetic patients. The standard of care has evolved since BARI-2D was initiated and many of the early patients in the trial did not receive the care we now know to be most effective."
For more information: www.scai.org