Adding a few minutes to attempts to resuscitate patients who suffer a heart attack in hospital can significantly boost their chances of survival, a study published in The Lancet medical journal on Wednesday said.
Researchers led by Zachary Goldberger at the University of Washington looked at a database where US hospitals record details of revival efforts after a cardiac arrest.
The registry covered 64,000 patients from 435 US hospitals between 2000 and 2008.
On average, hospitals spent 20 minutes on attempted resuscitation before a patient was declared dead.
But hospitals that tried longest (those whose efforts averaged 25 minutes) had a 12-percent higher chance of patient response than those whose efforts (average 16 minutes) were shortest.
Survivors after longer resuscitation were just as likely to be free of brain damage than those who were resuscitated more quickly, the survey found.
The study said that, in developed countries, between one and five out of every 1,000 hospitalised patients have a cardiac arrest. Of these, 20 percent survive.