DR. GRANGER: This is Dr. Christopher Granger. I’m a Professor of Medicine, Professor in the School of Nursing, and Member in the Duke Clinical Research Institute at Duke University School of Medicine. With me today are Dr. Deborah Diercks, Professor and Chairman of Emergency Medicine at UT Southwestern Medical Center, Dr. Peter Berger, Senior Vice President of Clinical Research and an Interventional Cardiologist at Northwell Health, and Dr. Timothy Henry, Director of Cardiology at the Cedars-Sinai Heart Institute.
Let me introduce the topic of acute coronary syndrome (ACS) institutional protocols by stating that there are a wide variety of evidence-based options for the management of patients presenting with ACS. We have good evidence that these treatments are applied in an inconsistent way, and that there is substantial opportunity for better application of treatments that are proven to improve outcomes.
Part of the reason for the gap between effective applications of these treatments is the lack of a systematic approach that includes, I would suggest, several different areas that we can touch on. Those include the interface between emergency medical services (EMS), emergency departments (ED), catheterization labs, and the hospital wards. Another major opportunity is to improve the transition to outpatient care at the time of hospital discharge. Between different institutions, oftentimes even in the same health system, there is lack of coordination of care.
Then there are distinct issues in the different categories of patients, including patients with ST-segment elevation myocardial infarction (STEMI), with non-STEMI, and with cardiogenic shock. There are patients presenting with ACS who will need bypass surgery, and there are issues in what to do in the gap between presentation and undergoing bypass surgery.
Deb, as our emergency medicine representative, please provide some perspective on what you see as the challenges that can be addressed through a more systematic approach, including algorithms and standard orders for patients presenting with the spectrum of ACS.
DR. DIERCKS: Currently practice is patient-dependent and it is institution-dependent. The biggest challenge is getting that consistent strategy across all the providers that are going to eventually touch the patient. Specifically, I think the challenges are around the use clopidogrel, prasugrel, or ticagrelor, who you give it to, when you give it, and when you don’t.
STEMI patients are a little easier because they go up so quick, and in centers that do a lot of cardiac catheterization where a lot of the ED time is spent on early identification, rapid notification, and getting the patient ready to go. In my mind, it is really the patients with the non-ST segment elevation of ACS that are the biggest challenge, because that downstream coronary anatomy may or may not be known at the time.
When to initiate therapy and with whom to initiate therapy is always a big issue for us. I think standard orders make that easy. There are some places that use the History, Electrocardiogram (ECG), Age, Risk Factors, and Troponin (HEART) score1,2 or the Thrombolysis in Myocardial Infarction (TIMI) score3 to help guide therapy. However, there is inconsistency amongst practitioners.
DR. GRANGER: What are you doing, Deb, in your health system now with respect to standardizing care. Do you have an algorithm, or is it more dependent on the individual ED? How are you addressing that?
DR. DIERCKS: The two institutions at which I have the pleasure to work actually manage things very differently. Our bigger county hospital will really limit the administration of dual antiplatelet therapy. In particular, we use clopidogrel and limit the administration of that to someone with a TIMI score of over four if they’re getting admitted for non-ST segment elevation ACS.
The private hospital is much more dependent on who is on-call, and they like a discussion because they have a higher prevalence of disease at that institution, and the rate of coronary artery bypass graft is much higher. There is often a discussion prior to any medications administered other than aspirin and anticoagulation.
DR. GRANGER: Peter, you’ve done a lot of thinking about systems of care and you have worked in Geisinger, and now in Long Island in a huge healthcare system. Would you comment on what your experience has been? Maybe also comment about whether or not there is an optimal approach, or is the optimal approach really still somewhat subjective?
DR. BERGER: I do think that despite all of the studies, there remain a lot of unanswered questions. That contributes to the fact that there is such wide variation in practice patterns. Like Deborah said, I do tend to be a splitter, and think of how I would want to treat patients with different kinds of ACS differently. I think that makes sense. Patients with ST elevation, patients with clear-cut non-ST elevation infarction, people with unstable angina, and patients whom you are unsure have an ischemic basis for their pain—I think you could make very sound arguments based on the limited knowledge we have that there are different optimal treatment patterns for all of them.
I also share Deborah’s view that eliminating the unjustified variation in the way these patients are cared for is good for patients and for our health system. If a patient with a particular type of presentation finds themselves in the ED, and the way they are treated depends on who is on-call or who will ultimately be assuming responsibility, I think that generally represents a weak system of care.
Now, you asked about Geisinger versus Northwell Health, which is not only on Long Island, but the five boroughs of New York City and Westchester and now crossing the Hudson River. The practice patterns there were somewhat different. Geisinger is a 100+-year-old health system, very mature, fantastic informatics, very well-connected electronically, and it has a very mature STEMI network. Patients received pretty much the same standard treatment anywhere they presented at the roughly 18 hospitals that referred patients for primary percutaneous coronary intervention (PCI) to Geisinger’s tertiary care centers.
Northwell has tripled in size in less than 7 years; it has 21 hospitals, and is still growing rapidly. It is not yet as well aligned, and there are still important differences in the treatment that patients will receive depending on where they present in the system. I hope and expect that this will change, and that we will be successful in the near future at eliminating unjustified variation and, instead, base treatment patterns on the best available data.
DR. GRANGER: Peter, what we would like to do, I think, is make recommendations to our readers about what should be done, and where there are options. Maybe one of the principles is to try to be relatively simple and streamlined, at least in terms of some of the most basic decisions.
Let me ask you, from the point of view of the EMS, what is your current recommendation for EMS for, let’s say, a patient who is diagnosed with a high likelihood of ACS? Maybe in this case the best example would be a STEMI. Do you think there is a role for doing anything with antithrombotic therapy other than giving 325 mg of aspirin in the United States?
DR. BERGER: Great question. If I was having a STEMI and a prehospital ECG was clear-cut, and I was being taken for primary PCI, I’ll tell you what I would like, even though it is not strongly supported by the data. I would like my aspirin and P2Y12 inhibitor administered as early as possible, ie, at the time of diagnosis.
I know that hasn’t yet been proven to be beneficial in randomized trials. It cannot, however, be that a P2Y12 inhibitor beats placebo in STEMI, and yet pretreatment can’t be better than post-procedural treatment. It is just that it is hard to demonstrate, and has not yet been demonstrated to be beneficial in the trials that have examined it. Nonetheless, without firm evidence, that is what I would want to receive: a P2Y12 inhibitor administered at the time of diagnosis, or as early as possible after diagnosis, if the diagnosis of STEMI was clear-cut and I was heading to primary PCI.
DR. GRANGER: Deb, what is your sense about that? Are you seeing ambulance staff, paramedics, giving P2Y12 antagonists, and is that something we should be moving toward?
DR. DIERCKS: I don’t see it happening and haven’t heard of an EMS system that is doing it yet in the United States, although that may just be my bandwidth. I think the challenge is what is a clear-cut STEMI? And are prehospital ECGs accurate enough in the United States where you’ve got paramedics reading them or basing it on the computerized diagnosis of STEMI? We know there is a high rate of false positive activations now. Do I think there is a significant risk to give it early? Probably not, but I think that is going to have to be weighed carefully with the consequences of treating the wrong patient.
DR. GRANGER: I think that is a key issue. We do know when paramedics activate, there is about a 25% over-activation or false activation rate. That may be high enough that being somewhat more restrained in the more potent treatments is prudent unless, as Peter points out, those are the cases that are perfectly clear-cut. Tim Henry has done good work reporting on this issue of “false activation” of the catheterization lab for STEMI.
DR. BERGER: Chris, let me just say one additional thing. As you know, not only do paramedics vary in their skill of reading ECGs, but also different systems use different approaches to ECG analysis for patients with a possible STEMI. For example, at Geisinger, a paramedic would transmit the ECG to an emergency room physician at the tertiary care center that the patient was being taken to. When it was thought to be a case of clear-cut symptoms, the “false positive” rate was much, much smaller than what you just quoted. When very skilled paramedics interpret ECGs, or when they are over-read by physicians who are good at reading ECGs, and a patient has clear-cut symptoms consistent with a STEMI, the false positive rate is not very high.