U.S. cardiac arrest rate unchanged 30 yrs.

ANN ARBOR, Mich., Dec. 7 (UPI) -- Only 1-in-13 people survive out-of-hospital cardiac arrest -- a U.S. rate unchanged in the last 30 years, researchers said.

The study by the University of Michigan Health System in Ann Arbor concluded the chance of surviving an out-of-hospital cardiac arrest has not improved since the 1950s.

The analysis of 79 studies involving 142,740 patients, published in Circulation: Cardiovascular Quality and Outcomes, found 23.8 percent of the patients survived to hospital admission and 7.6 percent lived to be discharged from the hospital.

While half of cardiac arrests were witnessed by a bystander, only 32 percent received bystander cardiopulmonary resuscitation.

"Increasing bystander CPR rates, increasing the awareness and use of devices to shock the heart and keeping paramedics on scene until they restore a person's pulse needs to occur if we are ever going to change our dismal survival rate," Dr. Comilla Sasson, the study's lead author, said in a statement.

Cardiac arrest -- when the heart stops beating -- is different from, but may be caused by, a heart attack, where blood flow to the still-beating heart is interrupted.