Treatment of acute coronary syndromes has come a long way since 1969, when Dr. Arthur Moss and I held a symposium at the University of Rochester titled, The Prehospital Phase of Acute Myocardial Infarction. It was one of the first such events focused on the early pathophysiologic events and care of patients with symptoms of an acute myocardial infarction (Am. J. Card. 1969;24:609–11).
This meeting was held about 4 years after Prof. Desmond Julian in Edinburgh proposed the concept of a coronary care unit and a few years after Dr. Frank Partridge had organized the first mobile coronary care unit in Belfast, Northern Ireland, and Dr. Hughes Day established the first CCU in Bethany, Kan. These seminal efforts showed that patients with an acute MI were best cared for in the setting of a unit dedicated to the treatment of the pathophysiologic events associated with acute myocardial ischemia. Prior to the development of CCUs, patients with acute MIs were hospitalized in the general hospital ward without any special monitoring.
We became interested at that time in the prodromal symptoms leading up to the event and factors that lead to the decision to come to the hospital. We observed that approximately 3.5 hours elapsed from the onset of symptoms to hospital arrival (Circulation 1970;41:737–42). More than half of that time was taken up with the patient and or family making a decision to come to the hospital. It is more than likely that many patients who experienced an acute MI could have died in that time.
To deal with hospital delay, we among others urged for the first time that patients come promptly to the emergency department without consulting their physicians. This was a sharp departure from the standard of practice at that time. The rest, of course, is history. The floodgates were opened and the emergency departments (EDs) were deluged with the myriad of medical causes of chest pain, real and fancied. The emergency physicians were left to sort it all out.
Fast forward to the development of biomarkers, exercise technology, and imaging that developed from the need to define and identify the individual with an acute coronary event. Today there are approximately 8 million visits to the ED for chest pain and related symptoms. Of these, approximately 20% are defined as an acute coronary syndrome (ACS) event. Of the estimated 1.1 million myocardial infarctions annually in the United States, about half the patients survive and make it to the ED for care. Recent studies indicate that the diagnosis of acute MI is missed in 2.1% of them (N. Engl. J. Med. 2000;342:1163–70). Similarly, 2.3% of patients seen in the ED for unstable angina are discharged and their diagnosis is missed. The risk-adjusted mortality rate in those patients in whom the diagnosis was missed is associated with an increased mortality risk.
In response to this deluge of patients coming to EDs, more than 1,500 chest pain units have been established, most of them attached to an ED where patients can be monitored and evaluated outside of the hurly-burly atmosphere characteristic of emergency departments. These units were first established by the American College of Cardiovascular Administrators in 1991, which later merged into the Society of Chest Pain Centers and Providers (SCPCP). The organization is made up predominately of ED physicians and bridges the fields of emergency medicine, cardiology, and critical care nursing. Although often located within emergency facilities, they provide an atmosphere where patients can be evaluated using current diagnostic facilities at a cost less than that of the traditional CCU. They also expedite early therapy for patients with ACS by shortening door-to-needle time and by early administration of thrombolytic and pharmacologic therapy to minimize ischemia. The chest pain centers are now undergoing an accreditation process under the direction of the SCPCP.
To deal with this increased volume of patients coming to the ED for evaluation of chest pain, hospitals have modified emergency department facilities and procedures. The establishment of chest pain centers has provided a model of how chest pain patients can be expeditiously managed and treated in the face of increasing patient volume in an era of decreasing numbers of EDs nationwide.