Managing Pre-Hospital ECGs: The Devil Is in the Details

In the quest for improving door-to-reperfusion times in patients presenting with acute ST-segment elevation myocardial infarction (STEMI), the focus has shifted to pre-hospital management. The difficulties with managing and maintaining the apparently simple task of reliably transmitting electrocardiograms (ECGs) are demonstrated in this study. Implementing a relatively straightforward protocol involving emergency medical services (EMS) at a single site as a pilot study is admirably noted within this study. Using this strategy in combination with in-hospital efforts to reduce door-to-balloon times has been successful in many examples, including this one. One of the important findings within this study is that a local focus in reducing STEMI times applies to all patients, whether they are transported by EMS or arrive by private vehicle. However, expanding this from a local to a more regional level (or in this case, across disparate areas with a local focus) reveals many challenges and difficulties. Perhaps the most distressing portion of this report is the waning enthusiasm among EMS providers to use a proven modality in reducing door-to-reperfusion times. It is not surprising, given human nature, that when given the choice of a familiar and reliable ECG system without transmission capability versus a new and perhaps uncomfortable technology, providers often chose the former. In addition, the relatively unreliable new system likely added to provider bias to avoid its use. This suggests that an important focus for implementing pre-hospital ECG systems must include greater energy toward training EMS personnel with their new equipment as well as markedly improving transmission reliability. An alternative would be to remove the former technology and force the use of the new and important system, even if relatively unreliable in transmission. This study, while thought-provoking, has other concerns. The insignificant difference in group 1 mean and median door-to-reperfusion times when comparing the study to the post-study periods is alarming. One could argue that at some point Zeno’s paradox would apply to door-to-reperfusion times, but the reported 63-minute reperfusion times suggest a large potential for gain given the much shorter reperfusion times in the successful pre-hospital ECG group. Similarly concerning is that there were very few successful pre-hospital ECG transmissions (2.1%) in the multicenter group. We agree with the authors’ suggestion that local in-hospital measures to reduce reperfusion times were more likely the main reason for the 20-minute improvement. That said, this offers an obvious opportunity for further reductions in door-to-reperfusion times with an advancement in ECG transmission reliability and EMS familiarity with the new system. An often overlooked issue is the logistical complexity of managing pre-hospital ECG transmission. The focus on the EMS provider is critical, but ECG management by the emergency department (ED) and the cardiologist is also vital. Once a transmitted ECG is successfully received, it needs to be preserved within the hospital data system. This is more complicated than one might think because of the concerns about patient privacy and IT firewalls to prevent outside data intrusion. There is also a need to have physical space to house a receiver within the ED. Once received, a busy ED physician must review it in a timely fashion and also get in contact with the on-call cardiologist. Clinically, preparation for reperfusion also occurs, a complex ballet of many personnel involving activation of STEMI protocols and the catheterization laboratory. Post hoc management of the ECG data often requires matching ECGs transmitted with patient de-identifying data with the appropriate medical records. Unmentioned within this report is the false-positive and false-negative rates of ECG interpretation, which presumably would improve with pre-hospital ECG data and earlier involvement of the cardiologist. Finally, another unspoken potential roadblock to the expansion of pre-hospital ECG systems is their cost. This is not trivial in today’s financial climate. In this study, the transmitter and receiver were provided for free. EMS providers and hospitals are often asked to provide financial and other support for these systems with little financial gain, especially if the hospital is already meeting current time management guidelines for reperfusion. For a regional, i.e. countywide STEMI system, the largest cost is often borne by the local EMS provider(s) to outfit their vehicles with ECG transmission capability. These can cost many thousands of dollars per rig. In addition, the receiving STEMI centers are asked to bear the cost of a receiver — often software on a computer in the ED — as well as the cost of maintenance, adding up to several thousands of dollars per year. If we are to fully implement these time-saving measures, these financial burdens must be addressed with an aim toward convincing local and regional administrators of the clinical improvement in patient management and outcome. We applaud the authors for their success in implementing a pre-hospital ECG system at both a local and regional level of care, highlighting the important pitfalls in what would appear to be a relatively simple task. These challenges are nontrivial and can be frustrating for all involved in the care of STEMI patients and cannot be ignored. Indeed, the devil is in the details. ———————————————————— From Stanford University, Stanford, California. Address for correspondence: David P. Lee, MD, Interventional Cardiology, Stanford University, Room H-2103, 300 Pasteur Drive, Stanford, CA 94305-4322. E-mail: dplee@stanford.edu