A tiny device--albeit very expensive device-- that can send a life- saving shock to the heart may have been implanted unnecessarily into "hundreds of thousands of women," according to a study published Monday.
The devices, called implantable cardioverter defibrillators or ICDs, are used to prevent sudden cardiac death in patients with advanced heart failure, meaning that patients who hearts have been damaged by heart attacks or heart disease so that they can no longer efficient pump blood through the body.
Each ICD costs about $30,000 per device and Medicare currently pays for use of the devices in both men and women.
A number of studies have provided evidence that implanting these devices can save live, but the evidence that the devices work was based on trials in which most of the patients were men, and that's what has led some researchers to take a second look.
The analysis published Monday in Archives of Neurology pools data from five ICD trials that tested the devices or optimal medical therapy in 3,810 men and just 934 women.
When Dr. Hamid Ghanbari, of Providence Hospital Heart Institute and Medical Center in Southfield, Mich., analyzed the results in women he found no reduction in "all cause mortality" among women treated with the shock devices.
Reducing that finding to simple numbers, it means that one would need to treat 40 women with ICDs to save a single life, versus treating 12 men with ICDs to save a life.
"The exact reasons for the significant sex differences in ICD implantation rates are not well established, but perhaps some of this disparity is driven by the paucity of data for women in randomized clinical trials of ICD therapy," they wrote.
Dr. Rita F. Redberg, editor of Archives of Internal Medicine, put it this way in an editorial; "ICDs are being implanted in hundreds of thousands of women without substantial evidence of benefit, apparently based on the assumption that, to paraphrase an old saying, 'What's good for the gander is good for the goose.'"
Such reasons, Redberg said, was especially troubling given a recent analysis of data from the National Cardiovascular Data Registry, which "found that women have a 70 percent higher risk of major adverse events after ICD implantation than do men."
Dr. Stephanie Moore, of Massachusetts General Hospital in Boston agreed.
"We need to report data based on gender and reported ethnicity. We cannot treat patients as "all the same". On the contrary, we are all unique and through thoughtful research we can personalize treatment so the goose and gander both have the best," said Moore.
Redberg said the meta-analysis was more evidence that the FDA had dropped the ball by failing to require more sex-specific data on both drugs and devices.
The authors of the study also thought more studies would settle the question.
"The best answer to this problem would be to perform a clinical trial that specially targets women with heart failure to test the hypothesis of whether ICD implantation reduces their overall mortality rate," Ghanbari wrote.
But because current guidelines do not qualify recommendations for use ICDs based on gender and nor does Medicare stipulate a gender criteria for ICDs to treat heart failure, such a prospects for such a trial are slim.