Avandia and Heart Attacks: Hold Your Horses
The report in today’s New England Journal of Medicine about an apparent association between Avandia (rosiglitazone) and heart attacks made the front page of USA Today.
While it is an important study, it is important that we don’t go overboard until we have a little more information.
There is a key principle that we have looked at before: one study is rarely enough to prove that a thing is so. The scientific method is based on the principle of falsifiability: now that this data has been published it is up to scientists and investigators to try and disprove the finding.
The analysis in the New England Journal suggests that the risk of a heart attack increases by 43% for patients taking rosiglitazone compared to control groups, and the risk of death by heart attack by 64%. This data comes from the so-called “A Diabetes Outcome Prevention Trial” (ADOPT). This is one of three studies on the topic. The Diabetes Reduction Assessment with Ramipiril and Rosiglitazone Medication (DREAM) study that involved over 5,000 patients was published in the Lancet last September. This study showed small increases in cardiovascular events compared to controls, which were not statistically significant. The other key finding of the DREAM study was that it reduced the risk of progression of pre-diabetes to type 2 diabetes by 62%. That is important because it may mean that we need much longer studies: diabetes increases the risk of heart disease year after year. ADOPT involved more than 4000 patients, with the only significant relevant finding an excess of congestive heart failure episodes for rosiglitazone-treated patients compared with people who received the older diabetic medicine, glyburide (22 compared with nine events).
So there may be a signal there, but before stopping the medicine, we need to remember that the numbers of patients who developed problems is small. Obviously big enough if you are one of them, but the risk is still not that high given the high rates of heart diseases in people with diabetes.
There is another study on the horizon: The Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of Glycemia in Diabetes (RECORD) trial, which is a phase III trial specifically designed to analyze cardiovascular events connected to use of rosiglitazone. The study that hit the front page is a meta-analysis, and even the authors admitted that there were some weaknesses in it. Though it is a personal choice that people have to make with their clinicians, many experts think that we can wait for the results of the third study so that we can make some sensible decisions.
And for the record, I have no connections with the manufacturer of Avandia, GlaxoSmithKline.
Dr. Richard G. Petty, MD is a world-renowned authority on the brain, and his revolutionary work on human energy systems has been acclaimed around the globe.
He is also an accredited specialist in internal and metabolic medicine, endocrinology, psychiatry, acupuncture and homeopathy. He has been an innovator and leader of the human potential movement for over thirty years and is also an active researcher, teacher, writer, professional speaker and broadcaster. He is the author of five books, including the groundbreaking and best selling CD series Healing, Meaning and Purpose. He has taught in over 45 countries and 48 states in the last ten years, but spends as much time as possible on his horse farm in Georgia.
