(Bypass Angioplasty Revascularization Investigation with Diabetes Trial) Presented at the American Diabetes Association (ADA) Annual Scientific Sessions.
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. The Society for Cardiovascular Angiography and Interventions (SCAI) encourages healthcare providers to apply the findings of BARI-2D, when appropriate, to their patients, as studied in this trial. BARI-2D specifically applies to those with carefully controlled diabetes, multi-vessel but stable coronary artery disease (CAD), and few heart disease symptoms. This trial does not answer the question of whether all patients with diabetes and multi-vessel 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 looks forward to additional data from the upcoming FREEDOM trial, which may shed more light on revascularization options for this growing patient population.
What BARI-2D Demonstrates About Patient Care:
- Intensive surveillance of 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 - and challenge - 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.
- Drug-eluting stents (DES) are the standard of care for diabetic patients undergoing angioplasty and stenting. 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. 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 United States, more than 65 percent of whom die from heart disease or stroke.
Limitations of BARI-2D:
- Angiograms for all. 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. 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.
- Findings are not applicable for every patient population. 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. As always, SCAI emphasizes each patient must be assessed individually based on his or her unique condition. Diabetes patients in particular often suffer from co-morbid conditions that affect their overall care.
SCAI Physician Quotes:
"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," said Robert Chilton, DO, Director of the Cardiac Catheterization Laboratory, South Texas VA Medical Center. "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."
"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."
"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 ten 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."
"Revascularization, including angioplasty or bypass surgery, is critical for many diabetic patients," said Steven R. Bailey, SCAI President and Chief of the Division of Cardiology at the University of Texas Health Sciences Center at San Antonio. "No one questions for patients with stable angina, optimal medical therapy is important as one of the first steps to manage disease. But for many patients, medical therapy is not enough, and revascularization may be a safe and effective option for improving their quality of life."
"Further research is needed on what optimal medical therapy truly is for patients," said Robert Chilton, DO, Director of the Cardiac Catheterization Laboratory, South Texas VA Medical Center. "Many patients studied in BARI-2D were on medications that can pose significant risks, including heart attack and heart failure, or could have faced complications from combining insulin with other medicines. Knowing a patient's full medical profile and possible drug interactions is imperative to all physicians to achieve the best possible outcomes for our patients."