Review by Dana Hendry, MD
LLSA Reviews edited by Evan Schwarz, MD
Strategies for reducing the door-to-balloon time in acute myocardial infarction
Two months ago your institution began to require the cath lab to be available 24/7 for patients with acute ST elevation MIs. You were selected to head up the quality improvement committee for the ED. Your director has asked you to review the performance of the department with particularly emphasis on door-to-balloon times prior to the upcoming meeting with the cardiology department. After reviewing the data you see that not only is your mean time greater than 90 minutes but you only are meeting the 90 minute benchmark 70% of the time. What can you do to speed up the process? What can be done to make the process more efficient? What about pre-hospital activation? Does it work? Does it save time?
“ Strategies for Reducing the Door-to-Balloon Time in Acute Myocardial Infraction” Bradley et a., New England Journal of Medicine, November 30, 2006.
In patients that experience ST elevation MIs, the likelihood of survival is closely linked with early intervention and reperfusion therapy which is now percutaneous coronary intervention (PCI) in most hospitals. The time from arrival of the patient to the first balloon inflation during PCI should ideally be less than 90 minutes. In fact this is such an important time line for therapy that it has been included as a pay-for-performance measurements reported to the Joint Commission on Accreditations of Healthcare Organizations. In reality, it is a minority of hospitals which reach this goal. This study seeks to find the most effective strategies to help hospitals to achieve the door-to-balloon time of less than 90 minutes.
This was a cross sectional study of 500 hospitals that performed at least 25 cases of PCI a year for ST elevation MIs in the year prior to the study (2005). The 500 hospitals were randomly selected and sent questionnaires about strategies in place that help to reduce door-to-balloon time. They were specifically asked about the 28 key strategies that had been identified by Bradley et al. The average door-to-balloon times between hospitals from April-September 2005 were then compared.
Respondents included 365 out of the 500 hospitals. Of the hospitals that responded to the survey, there was no statistically significant difference in their teaching status, geographic location, or median door- to-balloon time but it was found that rural and for profit hospitals were less likely to respond. The hospitals which did respond had an average door-to-balloon time of 100.4 minutes, exceeding the 90-minute Joint Commission standard.
In analysis of the data, the following strategies implemented by the hospital were found to significantly reduce the door-to-balloon time. It was found that the specialty of the physician who activated the catheterization lab was a strongly correlated variable. When it was the emergency physicians activating the catheterization lab, without direct consultation of the cardiologist, the greatest improvements were made (8.2 minutes). False-activation of the cath lab by ED physicians occurred only 2 times in the 6 months prior to the survey as opposed to 1 time in hospitals where the ED physician was not activating the lab. Additional strategies include, having just a single call from the ED to the central page operator who in turn, notified the cath lab. This strategy shortened door-to-balloon time by 13.8 minutes. If the hospital had a policy in place requiring the cath lab staff to get to the hospital within 20 minutes of being paged, times improved by 19.3 minutes. With regards to pre-hospital arrival policies, hospitals that had emergency medical services activate the cath lab while the patient was en route shortened their times by 15.4 minutes as opposed to activation upon patient arrival in the ED. In addition, having real-time feed back for the staff in the ED as well as the cath lab along with having an attending cardiologist onsite reduced door-to-balloon times by 8.6 and 14.6 minutes, respectively.
Other policies were not associated with a significantly reduced door-to-balloon time. These included policies regarding EKG performance and assessment (such as provision of formal training in ACS assessment for triage staff members, dedicated EKG technicians in the ED, and dedicated EKG space in triage), transportation of the patient from the ED to the cath lab, and certain practices in the catheterization laboratory.
Despite the effectiveness of the strategies listed above, it is only a minority of hospitals which have implemented such policies and door-to-balloon times continue to be well above the recommended 90 minute marker. For example only 137 hospitals or 37.8% of respondents implemented one of the six key strategies for lowering door-to-balloon time. Many of these strategies such as having the ED physician activating the cath lab without prior consultation of a cardiologist, do not require any additional resources and would be a great place to start in reducing door-to-balloon time.
There were several limitations to this study which must be taken into consideration. For instance, the surveys were answered by a single respondent from a hospital and the policies which were reported were not independently confirmed. Additionally, the study was limited to the hospitals which reported door-to-balloon time as a CMS performance measure and therefore, potentially more aggressive in attempting to reduce these times. Also, since this was an observational study, the authors could not determine if some of the strategies were surrogates for unmeasured care processes which may have been important in reducing door-to-balloon times.
Review by Dana Hendry, MD Citation:
Bradley EH, Herrin J, et al. Strategies for reducing the door-to-balloon time in acute myocardial infarction. N Engl J Med. Nov 2006; 355(22): 2308-2320.
Column organized by Evan Schwarz, MD
Division of Emergency Medicine
Washington University in Saint Louis