A new study in the New England Journal of Medicine has generated a lot of media attention this week (such as this NY Times article). The study pooled prior randomized studies that compared patients taking the diabetes medicine Avandia (rosiglitazone) to patients taking other diabetes medicines or placebo and looked for differences in rates of heart attack.
The worrisome result was a statistically significant increase in the number of heart attacks in patients taking Avandia compared to patients taking placebo or other diabetes medication. The magnitude of this increase is difficult to ascertain from the information published in the paper. Though the media is reporting that the study showed a 40% higher heart attack risk with Avandia, this number is not at all informative. (For example if 10 in a million placebo patients had heart attacks compared to 14 in a million Avandia patients, that would be a 40% increased risk, but the actual magnitude of the risk is so tiny as to not deserve attention. If, on the other hand, 10 out of 100 placebo patients had heart attacks compared to 14 out of 100 Avandia patients, that would also be a 40% increased risk, but the absolute magnitude of this risk would be much more worrisome.)
The study has led the FDA to issue this warning to patients and physicians. The FDA warning notes that this study is very preliminary. It’s pooled from other studies that weren’t designed to measure heart attack rates, and there are other, conflicting studies. There are large ongoing trials that will answer this question definitively. So the FDA isn’t recommending that patients stop Avandia, just that they have a conversation with their doctors. After all, stopping a medicine that is controlling your diabetes is much more dangerous than any risk discovered in this study.