"This is the largest study to date demonstrating the benefit of immediate angioplasty in acute heart attack patients," says lead researcher Timothy A. Sanborn, M.D., chief of the division of cardiology at Evanston Northwestern Healthcare, in Evanston, Ill.

Data on 30,358 patients eligible for percutaneous coronary intervention (PCI, also known as angioplasty) at more than 700 hospitals were collected from the National Registry of Myocardial Infarction (NRMI).

The NRMI is one of the largest observational studies of acute myocardial infarction (heart attack). It includes data on more than 1.8 million heart attack patients in the United States.

"The implications are significant. Hospitals with diagnostic laboratories that meet American Heart Association/American College of Cardiology criteria for performing emergency angioplasty without on-site surgery should perform these life-saving procedures rather than transfer patients to another facility with on-site surgery," says Sanborn, who is also co-director of Evanston Northwestern’s Cardiovascular Care Center and a professor of medicine at Northwestern University.

Researchers examined in-hospital death rates and elapsed time from hospital door to angioplasty procedure for 1,935 patients at 97 facilities without cardiac surgical units where diagnostic catheterization or PCI procedures were performed electively. The data were compared with those for 28,603 patients treated at 562 hospitals performing elective PCI with on-site cardiac surgery units.

In-hospital death rates were 3.2 percent at facilities with diagnostic catheterization but no cardiac surgery, 4.4 percent at hospitals with PCI but no on-site surgery, and 5.0 percent at hospitals with PCI and on-site cardiac surgery. In the last group, death rates ranged from 6.5 percent among patients transferred from another facility to 4.8 percent among patients treated in-house.

The median elapsed time between patient arrival and angioplasty also varied significantly, depending on where the procedure was performed and whether the patient was transferred to a cardiac catheterization unit at the same hospital or elsewhere. If transferred from an outside facility, the average heart attack patient waited about 198 minutes before undergoing PCI, compared to 107 minutes at hospitals performing PCIs with or without surgical ability, and 96 minutes at facilities performing diagnostic catheterization without surgical units.

"The findings show that at almost 100 hospitals without on-site surgical ability, performing emergency PCI is both safe and effective," Sanborn says.

The data suggest that hospitals providing diagnostic heart catheterization could save lives by providing immediate emergency balloon angioplasty for acute heart attack patients, Sanborn says.

"Because any delay in providing PCI after a heart attack increases a patient's risk, selected hospitals with diagnostic catheterization laboratories should perform them rather than transfer these patients to another facility with on-site cardiac surgery," he says.

Sending heart attack patients elsewhere for angioplasty doubles the delay before the procedure can be performed, the researchers found.

"The American Heart Association and the American College of Cardiology have specific guidelines on performing angioplasty during acute myocardial infarction, and stringent criteria that should be met for hospitals without cardiac surgery on-site," Sanborn notes.

Although there was no analysis to determine if sicker patients might have been transferred elsewhere more often, death rates for transferred patients were more than one-third higher than in patients treated more rapidly.

He adds that as emergency angioplasty is performed by more hospitals without on-site cardiac surgery, a prospective analysis of results using national databases will be necessary.

Co-authors include Alice K. Jacobs, M.D.; Paul D. Frederick, M.D.; Nathan R. Every, M.D.; and William J. French, M.D.