(Bloomberg) -- One in five implantable defibrillators, devices used to shock a stopped heart back into proper rhythm, goes to patients who shouldn't receive them, a study found.
Complications and deaths are more frequent in patients who don't meet the recommended guidelines for the devices, according to a report released Tuesday in the Journal of the American Medical Association.
The inappropriate use of defibrillators that generate $6.6 billion in sales for makers such as Medtronic Inc., Boston Scientific Corp. and St. Jude Medical Inc. can diminish patients' quality of life, lengthen hospital stays and drive up costs, the researchers said.
The analysis of 111,707 patients found 22.5 percent didn't qualify for a defibrillator because they had recently undergone bypass surgery, were recovering from a heart attack or had newly diagnosed or dangerously advanced heart failure. Those patients were either excluded from studies showing defibrillators can be life-saving, or were found not to benefit from the devices.
"Clearly there is a lack of knowledge and a lack of awareness of the guidelines, and some patients were harmed," said Sana Al-Khatib, lead researcher from the Duke Clinical Research Institute in Durham, North Carolina, in a telephone interview. "More education is needed. Hopefully physicians will look at our results and reflect on their practices."
Effect on Sales
The findings could lead to a 5 percent decline in the $6.6 billion defibrillator market, said Larry Biegelsen, a Wells Fargo Securities LLC analyst in New York. The study may shave $155 million from Medtronic's annual sales, $84 million from Natick, Massachusetts-based Boston Scientific and $93 million from St. Jude, based in St. Paul, Minnesota, Biegelsen said.
"We view this as a worst-case scenario, because we do not expect this data to impact sales outside the U.S.," where 39 percent of the revenue is generated, he wrote Tuesday in a note to investors.
Also, many patients who don't yet qualify for a defibrillator may need one eventually, and some will qualify for more expensive devices used to resynchronize the heart, he said.
Medtronic is supporting several studies to identify patients who will benefit the most from therapies including implantable cardioverter-defibrillators, also called ICDs, said Wendy Dougherty, a spokeswoman the Fridley-based medical device maker. Sudden cardiac arrest kills 95 percent of patients within minutes, and the only effective treatment is a defibrillator, she said.
"Medtronic is only interested in appropriate implants, but we do believe that all patients who may reasonably benefit from an ICD should receive one," Dougherty said in an e-mail. "Sudden cardiac arrest kills more people each year than lung cancer, breast cancer and AIDS combined, more than 380,000 people per year."
Medtronic's shares fell 31 cents, or less than 1 percent, to $37.10 at 2:57 p.m. in New York Stock Exchange composite trading. Boston Scientific declined 12 cents $1.14, or 1.6 percent, to $7.48 and St. Jude dropped $1.11 or 2.6 percent, to $41.17.
Heart attack patients, those who have undergone surgery and those just diagnosed with heart failure may recover so well with other treatments that they may not need a defibrillator, Al- Khatib said. Patients with severe heart failure are so sick that they are unlikely to reap any benefit and they may suffer complications from surgery, she said.
Previous studies from the same group of researchers found many patients who are most at risk for sudden death, and should receive the implantable defibrillators, don't receive them, Al- Khatib said.
The devices should be used for patients with erratic heart rates, people in danger of sudden death and those whose hearts have a damaged electrical system, according to the National Heart, Lung and Blood Institute.
Patients who don't qualify for defibrillators are often sicker or less stable than those shown to benefit from the devices, the researchers said.
The study found 3.2 percent of patients improperly given defibrillators suffering complications, and 0.57 percent dying in the hospital, compared with complications in 2.4 percent and deaths in 0.18 percent of those who got the devices as directed.
"These complications resulted from procedures that were not clearly indicated in the first place," the researchers said. "While a small risk of complications is acceptable when a procedure has been shown to improve outcomes, no risk is acceptable if a procedure has no demonstrated benefit."
Heart doctors should act on the new results, said Alan Kadish and Jeffrey Goldberger from Northwestern University's Feinberg School of Medicine.
"If properly applied, the findings of the study by Al- Khatib et al may improve practice patterns and outcomes, with the unique opportunity to do so while lowering health care costs," they wrote in an editorial accompanying the study.
The study, funded by the National Heart, Lung and Blood Institute, is based on an analysis of medical records in the National Cardiovascular Data Registry for patients who received a defibrillator from January 2006 to June 2009.