Direct Paramedic Transport of Acute Myocardial Infarction Patients to Percutaneous Coronary Intervention Centers: A Decision Analysis
Presented at the Society for Medical Decision Making annual meeting, October 2007, Pittsburgh, PA; and the National Association of EMS Physicians annual meeting, January 2008, Phoenix, AZ.
Received 27 February 2008; received in revised form 13 June 2008; accepted 17 July 2008. published online 19 September 2008.
Study objective
One potential strategy in the emergency medical services (EMS) care of acute ST-segment elevation myocardial infarction (STEMI) is to bypass the nearest community hospital in favor of a more distant specialty center able to perform primary percutaneous coronary intervention. We seek to determine whether EMS transport of out-of-hospital STEMI patients directly to more distant specialty percutaneous coronary intervention centers will alter 30-day survival compared with transport to the nearest community hospital fibrinolytic therapy.
Methods
This decision analysis used parameter values and ranges from meta-analyses and North American clinical studies of STEMI and chest pain care published after 2001. The primary hypothetical interventions were primary percutaneous coronary intervention versus community hospital–delivered fibrinolytic therapy. We defined total STEMI treatment time as the sum of symptom duration, EMS response time, EMS scene time, EMS transport time to the nearest community hospital, additional EMS transport time to a more distant percutaneous coronary intervention center, and door-to-drug or door-to-balloon time. We related total STEMI treatment time to the primary outcome 30-day post-STEMI survival. We assumed that the closest specialty percutaneous coronary intervention centers were located farther than the nearest community hospital and that patients would receive primary percutaneous coronary intervention at specialty centers and fibrinolytic therapy at community hospitals. We assumed the use of ground transportation only and excluded situations with fibrinolytic therapy contraindications. We examined standard risk and best-case scenarios for each intervention, as well as changes in predicted risk with parameter value variations.
Results
Baseline total treatment times (chest pain onset to intervention) were percutaneous coronary intervention 188 minutes (range 41 to 447 minutes) and community hospital fibrinolytic therapy 118 minutes (range 51 to 267 minutes). Thirty-day survival was higher for standard percutaneous coronary intervention than standard community hospital fibrinolytic therapy (95.8% versus 93.8%; relative risk [RR] 1.021; number needed to treat 50) but lower when compared to best-case community hospital fibrinolytic therapy (95.8% versus 97.8%; RR 0.980; number needed to harm 50). Best-case percutaneous coronary intervention was equivalent to best-case community hospital fibrinolytic therapy (RR 1.000). In 1-way sensitivity analyses, best-case community hospital fibrinolytic therapy versus standard percutaneous coronary intervention was sensitive to treatment time parameter variations. Probabilistic sensitivity analysis favored standard percutaneous coronary intervention over standard community hospital fibrinolytic therapy (RR=1.020; 95% probability range 1.002 to 1.045) but did not indicate a favored strategy for the other scenarios.
Conclusion
In select out-of-hospital STEMI care scenarios, EMS transport of acute STEMI patients directly to percutaneous coronary intervention centers may offer small but uncertain survival benefits over nearest community hospital fibrinolytic therapy.
aDepartment of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA
bCardiovascular Institute, University of Pittsburgh, Pittsburgh, PA
cSection of Decision Sciences, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
Address for correspondence: Henry E. Wang, MD, MS, Department of Emergency Medicine, University of Alabama at Birmingham, 619 19th Street South, Birmingham, AL 35249-7013; 205-975-7387
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article, that might create any potential conflict of interest. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement. Dr. Wang is supported by Clinical Research Development Award K08-HS013628 from the Agency for Healthcare Research and Quality, Rockville, MD.
Earn CME Credit: Continuing Medical Education is available for this article at: www.ACEP-EMedHome.com.
Supervising editor: Kathy J. Rinnert, MD, MPH
Author contributions: HEW conceived the study. HEW, OCM, and KJS designed the analysis. HEW carried out the analysis. All authors contributed substantially to the writing and editing of the article. HEW takes responsibility for the paper as a whole.
Reprints not available from the authors.
Publication date: Available online September 18, 2008.
ABSTRACT
Direct Paramedic Transport of Acute Myocardial Infarction Patients to Percutaneous Coronary Intervention Centers: A Decision Analysis