Swiftly transporting heart attack victims to the emergency room (ER), and thus treating them more quickly, has not been linked to lower death rates, according to a recent study.

"The door-to-balloon time was the low-hanging fruit," Dr. Hitinder Gurm, an associate professor of internal medicine and co-author of the study, told Reuters. "From the patient's viewpoint, the heart muscle starts to die the moment the symptoms start, and it keeps dying until the artery's opened. And most of the delay happens before the patient comes to the hospital."

Door-to-balloon time starts when the patient arrives at the ER and ends when a catheter is placed between blood vessels in the heart during percutaneous coronary intervention (PCI) treatment. "Our findings raise questions about the role of door-to-balloon time as a principal focus for performance measurement and public reporting," Gurm and his colleagues stated.

A PCI, or an angioplasty with a stent, uses a catheter to place a stent in the blood vessels of the heart so that blood can flow more easily. The procedure successfully decreases plaque buildup in the heart without the use of surgery.

A research team led by Gurm used 96,738 cases of ST-segment elevation collected by 515 U.S. hospitals for the basis of their study.

The findings showed a five percent death rate in the first year of the analysis when the average door-to-balloon time was 83 minutes. The death rate dropped only to 4.7 percent three years later when the average time was 67 minutes.

According to Gurm and his fellow researchers, healthcare professionals should be more worried about getting the patient to the actual hospital. Although door-to-balloon time is the current measure of quality for hospitals, it's only one part of treating someone who has suffered a heart attack.

"The door-to-balloon time rates dropped significantly, but we were disappointed to see that there wasn't a decline in mortality," Dr. Daniel Menees, an assistant professor of internal medicine and co-author of this study, told HealthDay. "Even when we act quickly, heart cells are dying. By the time patients get to the hospital and get into treatment, it's been two to three hours and there's only so much heart we can save."

Source: Peterson E, Curtis J, Messenger J, Rumsfield J, Menees D, Gurm H. Door-to-Balloon Time and Mortality among Patients Undergoing Primary PCI. New England Journal of Medicine. 2013.