Where are all the AEDs?

Susan Koeppen has no memory of the day her heart stopped pumping blood. She cannot remember the morning jog she took with a friend, nor can she recall stopping in mid-run, bending over to catch her breath, and then collapsing to the pavement.

Koeppen, a news anchor for Pittsburgh, Pa., television station KDKA, learned the details of her brush with death from her jogging partner (and friend) Beth Sutton.

After collapsing during their jog (which Koeppen considered training for an upcoming half-marathon), Sutton flagged down two passersby, who fortunately were University of Pittsburgh medical students. The pair administered cardiopulmonary resuscitation (CPR) while another friend dialed 9-1-1. An emergency medical technician who responded to the 9-1-1 call restarted Koeppen’s heart with an automated external defibrillator (AED) and rushed her to a hospital, where she received an implantable cardioverter-defibrillator and eventually underwent surgery to repair a damaged mitral valve that caused her sudden cardiac arrest (SCA). Afflicting nearly 300,000 Americans annually, SCA usually strikes without warning, often occurring in people like Koeppen with no previously recognized symptoms of heart disease. If normal heart rhythms are not restored quickly, SCA can be fatal.

Since her near-death experience, Koeppen has helped support a campaign by the Pittsburgh-based Sudden Cardiac Arrest Foundation to ensure that AEDs are placed in airports, office buildings, schools, recreations areas, shopping malls, and any other place people gather.

The Foundation’s effort is a daunting one, considering AEDs are not always accessible to those who most need them. Research from the Perelman School of Medicine at the University of Pennsylvania found that more than 75 percent of cardiac arrest victims are stricken too far away from an AED for the device to help save their lives. Victims like 12-year-old Jeremy Herbert, who died of an enlarged heart at a Covington, La., middle school that did not have a defibrillator, or Florida teenager Andrew Cohn, who died after colliding into another baseball player (which triggered a fatal heart rhythm known as commotio cordis) on a baseball field with no AED.

An estimated 1 million AEDs have been sold in the United States but their precise whereabouts is a mystery because the defibrillators are not subject to the same U.S. Food and Drug Administration regulations as implantable medical devices. The Penn study examines whether AEDs are located in areas where people are most likely to suffer cardiac arrests.

The Perelman School of Medicine team mapped the locations of 3,483 out-of-hospital cardiac arrests and the locations of 2,314 AEDs throughout the Philadelphia, Pa., area. Researchers found the devices most commonly located in schools and on university campuses (30 percent), in office buildings (22 percent), and in residential buildings (4 percent). However, just 7 percent of cardiac arrests occurred within a 200-foot radius of an AED (about a two-minute walk, roundtrip, from the scene). Ten percent occurred within 400 feet (a four-minute walk) and 21 percent took place within 600 feet (a six-minute walk) of an AED. Victims’ chances of survival fall roughly 10 percent with each minute that passes without CPR and defibrillation, according to industry data; thus, patients who are shocked six minutes or more after their hearts stop beating are not very likely to survive the episode.

“AEDs are an essential part of the chain of survival that’s necessary to save cardiac arrest victims,” said Raina Merchant, an assistant professor of emergency medicine at Penn and the senior author of the report presented during the SAEM meeting. “Despite thousands of them in the community, our results show they are usually not readily available during cardiac arrests. Without an AED, the minutes bystanders spend waiting for paramedics to arrive could mean the difference between life and death.”

The investigators argue that their findings underscore the need to place AEDs more strategically in communities, and find innovative ways to help the public easily locate and use them in emergencies, as precious time often is wasted hunting for the devices even when they are nearby. Over the past winter, a Perelman team conducted the MyHeartMap Challenge, a crowdsourcing contest that sent Philadelphia residents to the streets to locate, capture and map, via a special smart phone app, the locations of all of the city’s AEDs. More than 350 teams and individuals participated in the contest, searching out more than 1,500 AEDs, in about 800 unique buildings around Philadelphia. The top two finishers received $9,000 each, and the data collected will be used to create a mobile app to help bystanders locate the nearest AED during emergencies. It also will be provided to 9-1-1 operators to direct bystanders to AEDs to use while waiting for paramedics.

“Each of the AEDs the MyHeartMap Challenge participants located represents an opportunity to save lives,” said Merchant, who serves as MyHeart Map Challenge director, “but we need to ensure that the devices are in places where they will be most useful and accessible, and develop ways to make sure people know where to find them quickly when they’re needed.”