Deaths from ST-segment elevation myocardial infarction have remained the same even though hospital teams have gotten faster at treating patients with emergency angioplasty, according to a study.
Hospitals across the country have successfully raced to reduce door-to-balloon times to 90 minutes or less in the belief that it would save heart muscle and lives, according to background information in the study, which was published in the Sept. 5 issue of the New England Journal of Medicine.
In an analysis led by researchers with the University of Michigan Frankel Cardiovascular Center of 96,738 STEMI admissions across the United States between 2005 and 2009, a time period that coincided with a national effort to reduce door-to-balloon time, 4.7% of patients died. The rate was virtually unchanged in spite of the faster care.
The data suggests that efforts to reduce door-to-balloon time further may not result in lower death rates, Daniel Menees, MD, the studys lead author and an interventional cardiologist and assistant professor of internal medicine at the University of Michigan Medical School.
Potential strategies to improve care may include increasing patient awareness of heart attack symptoms, reducing delays for treatment once symptoms begin and shortening transfer time between healthcare facilities once a heart attack is recognized.
In the study of patients treated for STEMI at 515 hospitals participating in the CathPCI Registry, average door-to-balloon time fell from 83 minutes in 2005-06 to 67 minutes in 2008-09. The percentage of patients receiving care in 90 minutes or less improved from 59.5% to 83.1%. However the mortality rate remained virtually unchanged at 4.8% in 2005 and 4.7% in 2009.
The findings show the result of collaboration and teamwork among teams led by cardiologists, emergency medicine clinicians and emergency medical services to reduce treatment time.
Healthcare quality has been measured in part by how well hospitals meet the 90-minute time goal. The U-M Health System is among those hospitals publicly reporting its own performance online.
But the pendulum may have swung too far, Menees said. In our rush to provide treatment even faster, we may be taking patients for angioplasty who dont need one and possibly even placing those patients at risk.
Door-to-balloon time is easy to measure and something we can control, but its only a fraction of the total ischemic time.
Each year, almost 250,000 Americans suffer a STEMI. Said Hitinder Gurm, MD, the studys senior author and an interventional cardiologist and associate professor of internal medicine at the U-M Medical School: Emergency teams and the cardiology community have worked hard with the hope that reducing door-to-balloon time would improve patient outcomes. These efforts have been widely successful. Whats disappointing is that the reduction has not been accompanied by a change in mortality.
Study abstract: www.nejm.org/doi/full/10.1056/NEJMoa1208200.