The results also showed that the chance of missing out on lifesaving emergency treatment was highest among patients without typical symptoms like chest pain, patients who did not arrive at the hospital until six or more hours after the heart attack began, female patients, those over age 75 and non-whites.
The 10-year study was based on data from 238,291 heart attack patients between 1994 and 2003 who were listed in the National Registry of Myocardial Infarction. The patients had a particular kind of heart attack called ST-elevated myocardial infarction (STEMI).
It is the most current and comprehensive look at the use of emergency reperfusion, a treatment that can restore blood flow to the heart muscle. To track the changes in emergency reperfusion therapy over time, the researchers divided the study data into three time periods: June 1994 through May 1997, June 1997 through May 2000, and June 2000 through May 2003.
"This study has good and bad news," said senior author Harlan M. Krumholz, M.D., the Harold H. Hines, Jr. Professor of Medicine at Yale School of Medicine. "We have definitely made progress in treating appropriate patients, but our findings indicate that we need to improve further to be sure that no patient who could benefit from treatment is missed."
"We may never be able to get to 100 percent, but 10 percent of eligible patients going untreated is still too many," said first author Brahmajee Nallamothu, M.D., assistant professor of cardiovascular medicine at the University of Michigan Medical School. "We hope our study highlights the opportunities to improve care and particularly some of the "at risk" subgroups still less likely to receive reperfusion therapy despite eligibility, so that we can focus our clinical efforts on them."
Hospitals around the nation, including Yale-New Haven and University of Michigan, are taking part in a national campaign to reduce "door-to-balloon" times—the time from when a STEMI patient enters hospital doors to the time blood flow is restored to the heart by opening a blockage with angioplasty.
The National Heart, Lung and Blood Institute of the National Institutes of Health funded the study. Genentech, Inc. provided researchers with access to the registry.
Source: YALE University