Driving times and distances to hospitals with percutaneous coronary intervention in the United States

Mar 15 2006

Diverting ambulances with patients suffering a heart to a hospital providing emergency angioplasty rather than a closer hospital with no ability to provide this specialized care, may be feasible for the majority of Americans, researchers at Yale School of Medicine and the University of Michigan report in Circulation.

The study, presented at the annual meeting of the American College of Cardiology, shows that about 80 percent of Americans live within an hour of a hospital that offers emergency angioplasty, which is considered the best treatment for patients with ST-elevation acute myocardial infarction (STEMI). According to the authors, patients with STEMI could be treated more like trauma patients, with ambulances taking certain patients to specialized hospitals that perform emergency heart procedures, rather then transporting them to the nearest hospital.

Only a small percentage of American hospitals perform angioplasties, which re-opens blood vessels and can be done electively to prevent a heart attack or urgently to treat one. The authors say the number of hospitals performing this care is rising and the majority of heart patients do not have geographic limitations. The team found that the median driving time to an angioplasty hospital was about 11.3 minutes, or 7.9 miles. The team made their findings by combining and analyzing data from the 2000 U.S. Census, the American Hospital Association's database of hospital locations, driving distances and estimated driving times.

"The study puts in perspective what it would mean for patients to be diverted from the closest hospital to one that performs angioplasty," said senior author Harlan M. Krumholz, M.D., the Harold H. Hines, Jr. Professor of Medicine. "For some patients, the difference in time is trivial, for others it may add a potentially dangerous delay to their treatment. It suggests that a national policy needs to take into account local geography."

A key issue raised in the study is the ability of ambulance crews to distinguish STEMI heart attacks from other problems using portable electrocardiogram equipment, since only STEMI patients have been shown to benefit most from emergency angioplasty than from fibrinolytic (clot-busting) drugs that are provided at most hospitals. The authors say this research is a first step that does not yet address implementation and economic issues.

"There are many more issues involved in regionalizing heart attack care, with proximity to specialized hospitals being necessary, but not sufficient, for making such a system feasible," said lead author Brahmajee K. Nallamothu, M.D., of the University of Michigan Medical School.

In addition to Krumholz and Nallamothu, other authors on the study are Eric R. Bates, M.D., Yongfei Wang and Elizabeth H. Bradley.