(NaturalNews) There is no evidence that implantable defibrillators are able to save women's lives, according to a study conducted by researchers from the Providence Hospital Heart Institute and Medical Center and published in the Archives of Internal Medicine.
"Implantable cardioverter-defibrillators are being implanted in hundreds of thousands of women without substantial evidence of benefit," wrote Rita Redberg of the University of California-San Francisco in an accompanying commentary.
Implantable defibrillators are used to treat people who suffer from heart failure, meaning that their hearts do not pump blood effectively. Heart failure patients are particularly susceptible to a dangerous and often fatal condition known as cardiac death, in which the heart begins to quiver and stops pumping blood entirely. The defibrillators detect this abnormal quivering and deliver an electric shock to restart the heart's normal rhythm.
Installing one of the devices costs between $20,000 and $30,000, and defibrillator implantations make medical device companies roughly $6 billion per year.
Although a number of studies have found that implantable defibrillators significantly reduce the risk of death in heart failure patients, the researchers found that most of those studies contained few females.
"Our trials are biased towards males. Seventy to 80 percent are made up of male subjects," researcher Christian Machado said.
The researchers re-analyzed the results of five implantable defibrillator trials conducted between 1950 and 2008 but looked only at the 934 women participants. They found that women who had been implanted with the devices and also received drug therapy were just as likely to die from any cause as women who had received only drug therapy.
The same studies included 3,180 men, who were significantly less likely to die if they had been implanted with a defibrillator.
"There seems to be much less significant benefit [in women]," Machado said.
Approximately 5.3 million people suffer from heart failure in the United States alone. Globally, the number is almost 22 million.