A new study shows that although door-to-balloon time has dropped significantly for heart attack patients, in-hospital mortality rates haven't improved.
Despite dramatic reductions in door-to-balloon time for patients with acute ST-elevation myocardial infarction (STEMI) who are undergoing percutaneous coronary intervention, in-hospital mortality rates have not improved, according to findings from a five-year study published in the Archives of Internal Medicine.
The study showed no change in mortality, in spite of the drops in the median door-to-balloon (DTB) time—the amount of time between a heart attack patient’s arrival at the hospital to the time he or she receives an intervention—at Michigan hospitals from 113 minutes in 2003 to 76 minutes in 2008.
“Considerable effort had focused on reducing door-to-balloon time with the assumption that quicker care translates into a significant reduction in mortality,” said the study’s senior author Hitinder Gurm, MD, of the University of Michigan Cardiovascular Center, Ann Arbor, MI, in a statement. “When we looked at our data, the reduction in door-to-balloon time was dramatic. However, to our surprise and dismay, we found the number of patients who died had not changed.”
Researchers at the U-M Cardiovascular Center and and Michigan hospitals tracked the outcomes of 8,771 patients with acute STEMI who were undergoing primary percutaneous coronary intervention from 2003 to 2008. Patients were stratified according to risk of death using a mortality model to evaluate whether risk factors affect the relationship between DTB time and mortality.
Current American Heart Association and American College of Cardiology guidelines for reperfusion therapy recommend a DTB time of 90 minutes or less.
By the end of the study period, nearly 70% of Michigan patients received care in the recommended door-to-balloon time.
“Our results suggest that a successful implementation of efforts to reduce door-to-balloon time has not resulted in the expected survival benefit,” said Anneliese Flynn, MD, the study’s lead author.
However, they found that in-hospital mortality remained unchanged at about 4%.
“The obvious next question is should we stop worrying about door-to-balloon time? I think that would be wrong,” Gurm said. “My concern is that door-to-balloon time is only one part of the delay that a patient has from the time their symptoms start to the time the artery is opened. We need to do a better job at educating patients and developing systems of care so that patients get to the hospital quicker and not only worry about the time involved once they hit the hospital door.”
To improve patient outcomes, he said, clinicians need to focus on the entire event—“from the moment a person experiences chest pain to the time they get treated.”
Although door-to-balloon time dropped, the study showed no improvement in the time between the onset of symptoms such as chest pain, and when patients arrived at the hospital.
“It could be that the negative impact of the increased symptom-to-door time among high risk patients is sufficient to mask any potential protective effect of the decreased door-to-balloon time,” Flynn said.
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Based on the results of this study, do you believe that AHA and ACC guidelines should be updated to reflect the need to improve patient outcomes along with door-to-balloon time?