Overcoming barriers to developing seamless ST-segment elevation myocardial infarction care systems in the United States: recommendations from a comprehensive Prehospital 12-lead Electrocardiogram Working Group

Abstract

Background

Reducing time to reperfusion treatment for patients with ST-segment elevation myocardial infarction (STEMI) improves patient outcomes. Few medical systems consistently meet current benchmarks regarding timely access to treatment. Studies have widely demonstrated that prehospital 12-lead electrocardiography can facilitate early catheterization laboratory activation and is the most effective means of decreasing patients' time to treatment.

Methods

We gathered experts to examine the barriers to implementation of prehospital 12-lead electrocardiographic monitoring and transmission to in-hospital cardiologists in creating seamless STEMI care systems (STEMI-CS) and propose multidisciplinary approaches to overcoming these barriers.

Results and Conclusions

Physicians, hospital systems, and emergency medical services often lack coordination of care delivery and receive fragmented funding and oversight. Clinical and regulatory guidelines do not emphasize local solutions to achieving clinical benchmarks, do not target incentives at all components of the STEMI-CS, and underemphasize risk-based approaches to protecting patient health. Integration of the multiple complex components involved in STEMI-CS is essential to improving care delivery.

Introduction

ST-segment elevation myocardial infarction (STEMI) affects 500 000 patients presenting with acute coronary syndrome in the United States annually.¹ The American Heart Association (AHA) and the American College of Cardiology (ACC) are leading a national campaign to improve outcomes by increasing the number of STEMI patients receiving timely reperfusion treatment.² Their 2004 and updated 2007 guidelines recommend that the interval from first medical contact or emergency department (ED) arrival to primary percutaneous coronary intervention be no longer than 90 minutes or that fibrinolytic therapy be initiated within 30 minutes of hospital arrival.1, 3 A 12-lead electrocardiogram (ECG) is the essential screening tool for identifying STEMI, supporting the decision to initiate reperfusion therapies. As such, since 2005, the AHA guidelines for triage of patients with acute nontraumatic chest pain depend upon prehospital 12-lead ECG for diagnosis as follows:

• (Class I): We recommend implementation of out-of-hospital 12-lead ECG diagnostic programs in urban and suburban emergency medical systems (EMS).⁴

• (Class IIa): Routine use of 12-lead out-of-hospital ECG and advance notification is recommended for patients with signs and symptoms of acute coronary syndrome.⁴

• (Class IIa): We recommend that out-of-hospital paramedics acquire and transmit either diagnostic quality ECGs or their interpretation of them to the receiving hospital with advance notification of the arrival of a patient with acute coronary syndrome.⁴

To date, few medical systems have been able to consistently meet these goals. A 2008 study of 254 hospitals participating in the AHA's “Get With the Guidelines” program found that, between 2001 and 2006, only 44.8% of 10 965 patients had door-to-balloon (D2B) times less than or equal to 90 minutes.⁵ In a 2006 study of 365 hospitals reporting D2B to the Centers for Medicare and Medicaid Services, the mean D2B time reported was 100.4 ± 23.4 minutes, demonstrating widespread challenges with providing treatment within recommended time intervals.⁶ In addition, data from the National Registry of Myocardial Infarction-4 for 2000 to 2002 indicates that fewer than 10% of patients with STEMI received a prehospital ECG,⁷ although this figure is likely higher in 2009. Multiple advisory councils and working groups have convened to recommend means of improving guideline adherence in STEMI care, including ones that focused on the optimal use of the prehospital 12-lead ECG in expediting reperfusion therapy decision making.2, 6, 8, 9 Recent work by an AHA council has provided a thorough academic assessment of the benefit of implementing prehospital ECGs into systems of care for acute coronary syndromes and has identified some of the barriers that have impeded this effort.⁹

The creation of an optimized STEMI care system (STEMI-CS) requires the integration of all providers that are involved in caring for the patient with STEMI, including prehospital EMS, ED physicians and staff, cardiologists in the cardiac catheterization laboratory and coronary care unit, and hospital administrators. Methods for integrating prehospital ECGs in early diagnosis vary from training-intensive approaches that allow skilled paramedics the decision-making power to activate a catheterization laboratory to technology-intensive solutions that improve physician-paramedic communication, providing in-hospital physicians immediate access to 12-lead ECGs taken in the field. The strategy of using paramedic interpretation to give advance notification of STEMI to EDs has been shown to reduce door-to-reperfusion time but not consistently below 90 minutes.¹⁰ Studies in which prehospital ECGs were transmitted directly to cardiologists for interpretation, while still en route to the hospital, have achieved success in consistently reducing D2B times to below 90 minutes.11, 12 Implementation of these more advanced strategies require EMS systems to be equipped with 12-lead ECG monitoring devices that can transmit ECGs to physicians with high-level ECG reading skills.