STEMI and EMS: Improving FMC2D Times

Posted on August 30, 2021
Tags: EMS

Many health emergencies require fast medical intervention, but certain incidents are particularly affected by the rate of response. ST-elevation myocardial infarction (STEMI) is a health crisis for which survival rates and other clinical outcomes are significantly impacted by time to treatment (specifically, time from vessel occlusion to coronary blood flow restoration).

Over the years, much has been published on how to decrease door-to-balloon (D2B) time, meaning how quickly a patient can go from arriving at the ED to reperfusion. Hospitals and various organizations have worked to drive down the average D2B time to under 60 minutes.

However, total ischemia time should not ignore prehospital response and care time – often called First Medical Contact to Door (FMC2D) – and its potential to further improve outcomes and get the patient to treatment more quickly.

Achieve Better Field Assessment

Accurately treating a STEMI patient depends on recognizing the symptoms as soon as possible. Look for any one of these symptoms as a potential STEMI case: chest discomfort (sometimes described as a heaviness or pressure that radiating into the left arm, jaw, or shoulder), shortness of breath, nausea, vomiting, weakness, or diaphoresis. Performing a 12-lead ECG with the first set of vitals is key. The recommended time from FMC to ECG is less than 10 minutes.

Remember that STEMI can be difficult to diagnose in older adults, females, or patients with diabetes. It may also evolve after the initial ECG. It’s a good idea to leave the leads connected and perform additional serial ECGs during transport while providing additional treatments per chest pain or appropriate protocols.

Improve Communication with the ED

Once STEMI is suspected, it’s important to immediately start communication with a provider (emergency physician, nurse practitioner, physician’s assistant, cardiologist, etc.) to confirm the interpretation of the ECG; EMS may also have someone trained in 12-Lead ECG interpretation on the team who can recognize the appropriate elevation levels. Transmitting the ECG data can ensure that the patient meets the STEMI alert activation criteria and help EMS determine the most appropriate destination and type of transport.

Technology has made it easier to transmit ECGs from the field to receiving hospitals, or even to a physician’s mobile device, for rapid ECG interpretation. This is especially helpful in situations where some but not all of the ECG criteria for STEMI are met, reducing significant delays in diagnosis and triage but also avoiding over‐activation from STEMI “mimics” like ventricular hypertrophy or early repolarization.

Choose the Best Transport Destination

In dealing with a STEMI case, the closest hospital might not necessarily be the best choice. Percutaneous coronary intervention (PCI) – also known as angioplasty – is currently the most effective method of reperfusion. It’s important to attempt to transport to a PCI-capable hospital when possible, even if another hospital is closer.

In fact, the American Heart Association Mission: Lifeline program (introduced in 2007 to develop systems of care for high‐risk, time‐sensitive cardiovascular conditions) recommends 9-1-1 response strategies that allow EMS providers to by-pass the closest “STEMI Referring” hospital when EMS First Medical Contact to PCI can be achieved in less than 90 minutes (or less than 120 minutes when transport time is greater than 45 minutes). At that point, air transport or an intercept with Advanced Life Support (ALS) transport may be considered if Basic Life Support (BLS) transport will be greater than 15 minutes.

Pre-Activate the CCL

In situations where minutes can make a life-and-death difference, requesting pre-activation of the Cardiac Catheterization Laboratory (CCL) while en routeto the hospital can be helpful. In this case, EMS providers issue a STEMI alert by notifying the ED as early as possible of an incoming STEMI patient. These PCI-capable hospitals will ideally have in place automatic acceptance protocols as well as on-call protocols for CCL staff.

Pre-activation allows for parallel processing of the patient while the CCL staff arrive, reducing the need for routine tests upon arrival and enabling the postponement of elective procedures to free up the required resources for the reperfusion. Some PCI-capable hospitals may even arrange with the EMS agency to bypass the ED and take the patient directly to the cath lab (often depends on whether CCL staff can arrive within 30 minutes of notification).

Track Performance Metrics

An important consideration in the pre-activation of CCL is careful monitoring and feedback; incorrect activation of the CCL can result in provider burn-out, higher expenses for the hospital (which often must pay extra to call in staff in off hours, even is a patient ends up not needing a PCI), or a lack of urgency in response to EMS STEMI alerts.

For example, recommended metrics to track relating to STEMI alerts might be:

  • Overcalls: EMS declared a “STEMI Alert” based on field impression, but the patient did not undergo emergency angiography or was not diagnosed with myocardial infarction. The exception would be patients whose conditions changed after the alert was issued.
  • Undercalls: A patient diagnosed with STEMI arrived by ambulance and underwent emergency angiography, but EMS did not declare a STEMI Alert before arrival at the ED.
  • Correct Calls: EMS issued a STEMI Alert with subsequent emergency treatment (considered a true positive); or, EMS did not issue a STEMI Alert and neither emergency angiography nor emergency thrombolytic administration was performed (a true negative).

Tracking these performance metrics can help EMS agencies ensure that they are efficiently utilizing STEMI alerts and CCL activations to best preserve the working relationship with the ED and PCI-capable hospitals in its network.

Software for Hospitals Can Help

Today software tools designed specifically for improving communication between hospitals and EMS are making rapid treatment of cases like STEMI more efficient. For example, alerting software for hospitals allow EMS to capture critical patient information at the scene, using smartphones and tablets to securely transmit data, photos, and videos to the ED. These tools also help hospitals prioritize cases, activate their teams, and even track arrival times down to the minute.

Similarly, software for bidirectional communication between hospitals and EMS allows hospitals to quickly and securely send patient outcome information directly to EMS agencies. This data sharing enables agencies to track performance metrics, identify trends, and ensure that alerts and activations are being used properly.

Focusing on improving response and transport protocols for potential STEMI cases involving EMS can not only help reduce first contact to balloon time, but potentially save lives. Better communication between EMS and hospitals opens lines of communication on the continuum of care and ensures that patients have the best chance of a positive outcome.