Consumers are unlikely to benefit from buying household versions of emergency equipment meant to revive victims of sudden heart seizures, according to long-awaited results from a clinical trial announced Tuesday.
The equipment — automated external defibrillators — has been marketed to health-conscious consumers for its ability to provide life-saving jolts of electricity to people whose hearts have stopped beating, or are beating so chaotically and rapidly that they could die within minutes.
In reporting their findings at a major cardiology meeting in Chicago and online in The New England Journal of Medicine, the researchers who conducted the trial noted that the devices clearly save lives in hospitals, emergency vehicles and in busy public settings like airports and casinos where trained employees are on duty.
But the study, which included more than 7,000 patients at risk of having the seizures because of previous heart attacks, found that patients in homes equipped with the gear died at the same rate as those without it.
The seizures, known as sudden cardiac arrest, strike about 125,000 Americans each year in their homes and 40,000 in public settings outside of hospitals. Unlike a heart attack, which involves a restriction of blood flow to the heart’s muscle and is often not fatal, sudden cardiac arrest is a quick killer. Some studies have shown the survival rate from such seizures in the home to be as low as 2 percent.
The government-supported clinical trial used the HeartStart Home Defibrillator from Philips Medical Systems, a $1,300 device approved for over-the-counter sale. Competing defibrillators from companies like Zoll Medical, Cardiac Science and HeartSine Technologies require a doctor’s prescription, but those are easily obtainable from the medical equipment companies that distribute them.
Another major competitor, the Physio-Control division of Medtronic, suspended distribution of its portable defibrillators in the United States last year while it sorted out complaints from federal regulators about its quality controls.
The home defibrillators currently account for less than $20 million of the $192 million market for portable defibrillators outside of hospitals, according to Mike Arani, an analyst in San Antonio with the market research firm Frost & Sullivan.
Advocates of the technology had hoped that positive results from the clinical trial might encourage investments to drive down the price to as little as $500, which could lead to a surge in sales.
Patients in the study — both those with the defibrillators and without them — fared surprisingly well, with fewer seizures than expected and higher than anticipated resuscitation rates. Everyone in the trial was trained to recognize the signs of sudden cardiac arrest, to call 911 immediately, and to give cardiopulmonary resuscitation, or CPR. Without immediate CPR, defibrillation is less likely to succeed.
Four of 14 patients whom the HeartStart deemed in need of a shock, and who then were given it, survived, according to the researchers. But the numbers were too small to be statistically significant.
The authors of the online report said that the result was “fortunate” for the handful of survivors but that any program to get defibrillators into homes would be “an inefficient strategy in public health terms.”
“There was a lot to be learned in this study,” said Michael Miller Jr., the head of cardiac care for Philips Medical Systems, which is a subsidiary of Royal Philips Electronics. Among other things, he said, more than half of the incidents occurred when no one was around to witness them, suggesting a possible market for better alert systems.
Mary F. Hazinski, a spokeswoman for the American Heart Association on home defibrillators, said that despite the study’s findings, home defibrillators might be a worthwhile investment in remote areas where quick emergency response was unlikely.
