Rochester, MN - The American Heart Association (AHA) has issued a scientific statement on the use of prehospital electrocardiograms (ECGs) to improve the quality of care delivered to patients with ST-segment-elevation MI (STEMI), published online August 13, 2008 in Circulation [1]. The central challenge, say the authors, will not be in acquiring the ECG, but rather in using and integrating the diagnostic information obtained by emergency medical service (EMS) personnel into existing systems of care.

"First medical contact with a patient is usually with the EMS, and this is the next phase of coordination that we need to reach out to," said lead author Dr Henry Ting (Mayo Clinic, Rochester, MN). "We've coordinated the emergency department, the cath lab, and the cardiology group and have done well with reducing door-to-balloon times, but we've not truly engaged the prehospital phase of care. This is critically important."

The public doesn't perceive EMS as transforming care. They view it as transportation with sirens.

The AHA national guidelines, as well as other consensus and scientific statements, recommend the acquisition and use of prehospital ECGs by EMS for the evaluation of patients with suspected acute coronary syndrome. The current recommendation is class 2a with a B level of evidence. Speaking with heartwire, Ting said that the technology is currently available, but that hospitals do not have protocols in place that allow prehospital ECGs to serve any useful purpose.

"For the past 10 years, this equipment has been available to many paramedics, but what is happening is that when they acquire the ECG it's not really utilized," said Ting. "It's acquired, then the patient is brought to the emergency department, and in hospitals without these systems of care, they're told this is a patient with chest pain, and we have an ECG, but then the patient is placed in a critical-care room and receives another ECG. Where's the value in that?"

In the scientific statement, the authors review the benefits of using prehospital ECGs and the barriers and challenges to routine use and recommend approaches for using the diagnostic information for improving quality of care. In terms of benefits, Ting said the Mayo Clinic has been incorporating the use of prehospital ECGs for one year, and in doing so, has reduced door-to-balloon times to consistently less than 30 minutes, with 25 minutes being the average.

Ting said there are many ways of interpreting the ECG once it has been obtained. Computer algorithms, paramedic interpretation, and wirelessly transmitting the data to a physician for interpretation are three ways to interpret the data. The diversity of the EMS providers and the differing sizes of cities they cover, as well as wireless coverage available to transmit data, are not likely to lead to a once-size-fits-all solution, he said.

A recent survey found that 90% of EMS systems serving the largest US cities have 12-lead ECG equipment, and there are prehospital ECG programs in Boston, Los Angeles County, and North Carolina, as well as in Ottawa, ON. Paramedics in Boston, for example, are allowed to bypass non-PCI hospitals and have an emergency-department physician activate the cardiac cath lab. North Carolina, on the other hand, allows paramedics to occasionally divert some STEMI patients to PCI hospitals and activate the cath lab directly (or have it activated by an emergency-department physician). Paramedics in Ottawa can also activate the cath lab directly through a central operator. Los Angeles County paramedics use a computer algorithm to interpret the ECG, and the cath lab is activated by the emergency department based on this diagnosis.

Allowing paramedics to "do something downstream" with the information is critical, said Ting, as is changing when the paramedics perform the ECG. "If you truly want to coordinate things, you want to start the prehospital ECG as early as possible in the examination," he said. "Once you establish that the patient has stable vital signs and doesn't have a cardiac arrhythmia, you probably want to do a prehospital ECG at the scene, as early as possible. If you detect ST elevation, the next steps are very different from treating a patient who has chest pain but no ST elevation."

Implementing prehospital ECGs into existing systems of care has the potential to "change the ball game," said Ting. He noted that the focus should begin to move away from door-to-balloon times toward a measure that provides a gauge of quality and performance that is more patient centered. The national "Door to Balloon: An Alliance for Quality" campaign launched in 2006 has helped improve the timeliness of lifesaving therapy for MI patients at all US hospitals that perform emergency angioplasty, but from a patient perspective, first medical contact to balloon is a more relevant measure of quality of care.

Ting added that too many patients still take themselves to the emergency department or are driven there by friends or family, a decision that affects the course of care because it's impossible to obtain a prehospital ECG and then activate all the necessary hospital teams.

"The public doesn't perceive EMS as transforming care," said Ting. "They view it as transportation with sirens. They think, 'If Uncle Joe can drive me there just as fast, then why do I need to call 911 and create all the hassle in the neighborhood?' But the prehospital ECG can really change the course of treatment, something that can't happen when you drive yourself or have a friend take you."