The chance of surviving an out-of-hospital cardiac arrest has not improved since the 1950s, according to a report by the U-M Health System.
The analysis shows only 7.6 percent of victims survive an out-of-hospital cardiac arrest, a number that has not changed significantly in almost 30 years.
It’s a dismal trend considering enormous spending on heart research, new emergency care protocols, and the advent of new drugs and devices such as defibrillators.
During cardiac arrest the heart stops beating and each year 166,000 people experience the frightening event away from a hospital.
But in the report in the current issue of Circulation: Cardiovascular Quality and Outcomes, an emergency physician says there are some key factors that can make a difference in saving lives when cardiac arrest happens at home, a hotel, restaurant or workplace.
“Our study shows that patients with a heart rhythm that can be shocked, or who have bystander CPR or a pulse restored at the scene of the event are associated with a much larger chance of survival,” says lead author Dr. Comilla Sasson, a Robert Wood Johnson Scholar and emergency medicine physician at UMHS.
Although half of cardiac arrests are witnessed by a bystander, according to the study, only 32 percent, or about 1 in every 3 people, received bystander CPR.
This is the first study to look at the associations between several clinical variables and overall survival from an out-of-hospital cardiac arrest.
The variables studied include: witnessed by emergency medical services provider, bystander CPR, types of heart rhythm — asystole (motionless) vs. ventricular fibrillation (rapid or twitching) — and return of spontaneous circulation.
Researchers evaluated data on 142,740 patients from 79 studies published internationally between January 1950 and August 2008.
Here’s what they found:
• Of the more than 140,000 patients, 23.8 percent survived to hospital admission, and 7.6 percent, or about 1 in 10 people, lived to be discharged from the hospital.
• Cardiac arrest victims who received CPR from a bystander or an emergency medical services provider, and those who had a shockable heart rhythm — referred to as ventricular fibrillation — were more likely to survive.
• The strongest predictor of survival was a return of spontaneous circulation, meaning a pulse was restored at the scene. Among them, 15.5 percent (in low-performing EMS systems) to 33.6 percent (in high-performing EMS systems) survived.
“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,” Sasson says.
The lack of progress in survival across the U.S. and abroad may be linked to an aging population, a lower number of people who are found in a shockable rhythm (which is associated with the highest chance of survival) and longer EMS drives due to the increasing size of cities and traffic congestion, authors write.
Mary Rogers, Department of Internal Medicine, also is an author on the study.
