Cardiac Arrest Survival Rates Vary Widely

Sept. 24 -- TUESDAY, Sept. 23 (HealthDay News) -- From city to city, there is a more than fivefold difference in the odds that someone will survive sudden cardiac arrest, with the chances resting on whatever emergency response system is in place, a new study finds.

"I expected there would be some differences, but the differences were greater than we expected, greater than for heart attack and stroke," said study author Dr. Graham Nichol, director of the Center for Prehospital Emergency Care at the University of Washington, in Seattle. His report was published in the Sept. 24 issue of the Journal of the American Medical Association.

The study included data on all 20,520 cases of cardiac arrest that occurred in eight U.S. and two Canadian sites, with a total population of 21.4 million, from May 2006 to April 2007. No attempt at resuscitation was made in almost half of all cases. Among the 58 percent who got emergency treatment, the survival rate, community by community, ranged from 3 percent to 16.3 percent.

Of the more than 20,000 people who suffered cardiac arrest, 954 (4.6 percent) of them lived to be discharged from a hospital.

The incidence of reported cardiac arrest cases receiving emergency treatment also varied widely, from 40.3 per 100,000 in the lowest-reporting community to 86.7 per 100,000 in the highest.

The great difference in survival rates are due "we think to incidence and risk, as well as how the community responds to cardiac arrest," Nichol said.

There is no single continent-wide step that can be taken to bring up survival rates, he said. "Every city needs to understand how well it is doing," Nichol said. "Cardiac arrest is a treatable condition, and cities should work hard to treat it better, rather than determining who should not be treated."

The last part of the statement referred to another report in the same issue of the journal, in which researchers studied the effect of two sets of do-not-treat rules developed in Canada. For example, one set said resuscitation should not be attempted if the cardiac arrest was not witnessed by emergency personnel, if no shock was given to restart the heart outside the hospital, and if circulation of the blood did not begin again.