Very Rapid Treatment of ST-Segment–Elevation Myocardial Infarction

Abstract

P rehospital ECG (PH-ECG) has been identified as a strategy to help reduce door-to-balloon (D2B) time during emergency treatment with percutaneous coronary intervention (PCI) for patients with ST-elevation myocardial infarction (STEMI). 1 National Registry of Myocardial Infarction data from 2000 -2002 suggest utilization rates of PH-ECG of Ͻ10%. 2 More recent analysis of data from the National Cardiovascular Data Registry-Acute Coronary Treatment and Intervention Outcomes Network Registry of Ͼ7000 patients with acute coronary syndrome transported by emergency medical services (EMS) during 2007 found PH-ECG utilization rates of 27.4%. 3 Among this cohort, D2B times were significantly shorter than the cohort of patients without PH-ECG, and there was a trend toward lower in-hospital mortality.Systems of care that have incorporated PH-ECGs into a citywide or region-wide strategy have demonstrated a significant reduction in D2B times, usually by triaging patients in the prehospital setting, bypassing non-PCI-capable hospitals, and transporting patients directly to a designated STEMI receiving center (SRC) capable of providing primary PCI. 4,5 Rapid and accurate interpretation of the PH-ECG is a critical step in the process of incorporating PH-ECG into systems of care for acute STEMI. Different models for interpretation of PH-ECGs have been described, including computer algorithm interpretation, wireless transmission to designated centers for physician interpretation, and direct paramedic interpretation. 1 Previous studies demonstrated that trained EMS personnel can reliably identify STEMI on the PH-ECG. 6,7 Goals and Vision of the ProgramWe initiated a program to evaluate a novel strategy to reduce D2B time for patients with STEMI who undergo PCI. The intent was to expedite prehospital triage and to reduce emergency department (ED) delays to treatment with PCI for patients with acute STEMI. We empowered EMS personnel to interpret the PH-ECG in the prehospital setting and then to activate the cardiac catheterization laboratory (CV laboratory) staff before transporting the patient to our SRC, facilitating direct transport of patients from the prehospital setting to the CV laboratory without stopping at any ED. We anticipated that this treatment strategy would decrease mean D2B times and result in a significant increase in the number of patients with D2B times Ͻ90 minutes in accordance with guidelines recommended by the American College of Cardiology and American Heart Association. Local Challenges in ImplementationWe identified 3 major barriers to the successful implementation of this program: training EMS personnel to acquire and accurately interpret PH-ECG for STEMI, modifying the treatment protocol at our SRC ED to facilitate ED bypass and rapid transport to the CV laboratory, and acceptance by the interventional cardiologists of their expanded role in evaluating and treating patients with STEMI who have not been preevaluated in any ED. Design of the Initiative Training EMS PersonnelOnly 50% of EMS organizations in ...

Emergency Department Bypass for ST-Segment–Elevation Myocardial Infarction Patients Identified With a Prehospital Electrocardiogram

“…Similar findings of shorter FMC-to-device times have also been observed with ED bypass in single-center studies. [10][11][12][13] As a result, our findings are consistent and noteworthy when considered in the context of the previously published relative impact of the implementation of the Door-to-Balloon Alliance recommendations on door-to-balloon times for patients with STEMI identified after hospital presentation (14-minute reduction) 14 and the impact of prehospital ECG performance on door-toballoon times (14-minute reduction). 15 The median 20-minute reduction in FMC-to-device time with ED bypass demonstrated in this analysis provided further incremental reduction in reperfusion times, contributed to a substantial improvement Model c index=0.92.…”

“…10 Although we observed significant variation in the use of ED bypass across hospitals in the United States, a small number of hospitals used ED bypass in >50% of their STEMI patients. Presentation during working hours appeared to most strongly influence the use of ED bypass, a finding that is likely explained by the proximity and availability of the primary PCI team when the hospital is first notified of the incoming STEMI patient by EMS.…”

“…Despite the differences in STEMI care and guidelines between the United States and Europe, recently published single-center experience indicates that ED bypass can be performed reliably and safely in the United States when there is a substantial institutional and physician commitment to adopt this process. 10 Although we observed significant variation in the use of ED bypass across hospitals in the United States, a small number of hospitals used ED bypass in >50% of their STEMI patients. Presentation during working hours appeared to most strongly influence the use of ED bypass, a finding that is likely explained by the proximity and availability of the primary PCI team when the hospital is first notified of the incoming STEMI patient by EMS.…”

Has the Time Come for a National Cardiovascular Emergency Care System?

“…23 In Minnesota, for example, the development of the first STEMI network led to the rapid adoption and deployment of multiple regional STEMI networks based on existing referral patterns that have improved the treatment of STEMI for patients throughout the region. 31,32 In addition, mechanisms for training medical students, residents, and fellows would need to be built into the system.…”

Retrospective Description and Analysis of Consecutive Catheterization Laboratory ST-Segment Elevation Myocardial Infarction Activations With Proposal, Rationale, and Use of a New Classification Scheme

“…3,4 Early identification of STEMI, especially in the prehospital setting, with direct transport to a SRC can lower the patients' total ischemic time and subsequently morbidity and mortality. 5,6 To optimize outcomes in patients who undergo field triage, prehospital electrocardiography (PH-ECG) is useful for identifying a STEMI and for early notification of the cardiac catheterization team, thereby shortening response times. This is especially important outside regular hours when cardiac catheterization laboratory (CCL) personnel are often not on-site.…”