The odds of surviving cardiac arrest may depend on which part of town you call home and whether anyone in the neighborhood comes to your rescue by attempting to perform cardiopulmonary resuscitation (CPR), according to a study in the June issue of the Annals of Internal Medicine.
Comilla Sasson, MD, from the University of Michigan in Ann Arbor, and colleagues analyzed emergency medical services (EMS) and 9-1-1 call data from the Cardiac Arrest Registry to Enhance Survival Rates (CARES), which was used to identify areas with higher incidences of cardiac arrest and low rates of bystander CPR.
CARES is an EMS web-based registry for out-of-hospital cardiac arrests. Census information was used to approximate neighborhoods. The study is believed to be the first to show relative stability in the incidence of cardiac arrest within census tracts from year to year.
A practicing emergency physician, Sasson became interested in identifying communities with higher incidences of cardiac arrest, while working as at Grady Memorial Hospital in Atlanta. There, she noticed that cardiac arrest patients from certain parts of Fulton County often arrived at the hospital already dead, while cardiac arrest patients from other parts of Fulton County arrived at the hospital alive and went on to make full recoveries.
Researchers found that certain neighborhoods in Fulton County, Ga.—which includes Atlanta—have an incidence of cardiac arrest two to three times higher than other parts of the county and fewer bystanders who attempt to perform CPR.
These findings remained across time, meaning that, year after year, residents of these neighborhoods were at the highest risk for a cardiac arrest event, and had the lowest rates of bystander CPR in Fulton County. These neighborhoods tend to have lower median household incomes, more African-American residents and lower education levels.
"These findings have national public health indications. They show that it is time to change our thinking on how and where we conduct CPR training if we are ever going to change the dismal rate of survival from cardiac arrest," said Sasson. "Nine out of 10 people die from a cardiac arrest event. This number can and must change."
In Fulton County, if rates of CPR performed by bystanders were improved to the level achieved by the highest performing parts of the county, an additional 355 people could receive CPR. This could save an additional 15 lives each year in Fulton County alone, according to the study.
CPR training often targets young, healthy volunteers who are least likely to encounter an individual in cardiac arrest. However, a public health surveillance registry based on that of the CDC can be used to design targeted interventions in the neighborhoods that need CPR training the most. Boosting bystander CPR rates in the U.S. from the current average of 27 percent to 56 percent could save an additional 1,500 lives per year, Sasson said.
An earlier study by Sasson in Circulation in 2009 found that the U.S. survival rate for out-of-hospital cardiac arrest has been at a standstill at 7.6 percent for nearly 30 years. Because most incidences of cardiac arrest occur outside a hospital and are often witnessed by bystanders, efforts to improve survival should focus on the prompt delivery of medical interventions such as the delivery of CPR, she said.
"Healthcare resources are extremely limited. To make improvements, we need to understand where and how best to make change," Sasson said.