Portal de Periódicos da CAPES

EVALUATING THE CHEST PAIN PATIENT

1999; Elsevier BV; Volume: 17; Issue: 2 Linguagem: Inglês

10.1016/s0733-8651(05)70077-1

1558-2264

Christopher R. deFilippi, Marschall S. Runge,

Cardiac electrophysiology and arrhythmias

Five million patients in the United States present annually to emergency departments (ED) with the primary complaint of chest pain of nontraumatic etiology.78 Depending upon the type of presentation, evaluation and triage of these patients may be straightforward or provide one of the greater diagnostic challenges for physicians. Three factors allow little margin for error when triaging these patients. First, 2% to 4% of patients with acute myocardial infarction (AMI) are inadvertently discharged from the ED with an associated short-term mortality of 10% to 26%.66, 79 Second, it has been estimated that 20% of ED-related malpractice dollars are expended for ischemic heart disease complications even though chest pain patients represent only 6% of the ED patient volume.108 Third, during the past 15 years there have been marked reductions in mortality and morbidity achieved by both the rapid identification and the treatment of subsets of patients presenting with AMI.23, 35, 42 Today, immediate in-hospital treatment of almost all patients with AMI or unstable angina (UA) can favorably impact prognosis.98, 100, 124 The goal, then, for the physician assessing chest pain patients in the ED is to identify not only virtually all patients with AMI, but all those with UA as well. As a group, AMI (particularly non–ST-segment elevation) and UA are referred to as acute coronary syndromes (ACS), reflecting the fact that both AMI and UA patients often share a similar coronary artery pathophysiology, as outlined in articles in this issue and elsewhere.123 The distinction between a diagnosis of AMI and UA is somewhat artificial in that it is based on the sensitivity of the biochemical markers, particularly creatine kinase (CK) MB, for detecting myocardial necrosis. Focusing on identifying only patients at risk for AMI or ruling out AMI by serial cardiac enzyme testing alone may neglect many patients with ACS who would benefit from early therapy to prevent progression to AMI and death. The scenario of inadvertent discharge of patients with ACS is often avoided by utilizing a very low threshold for hospital admission to the cardiac care unit (CCU) or a monitored bed setting for patients with atypical presentations. Typically, 50% to 70% of ED patients complaining of chest pain are admitted for further evaluation.39, 64 Only 25% to 30% are ultimately diagnosed with an AMI, however, and only 60% of those admitted are classified as having an ischemic etiology for their chest pain.62 Even taking into account the transition during the 1980s, when most patients at low risk of AMI were admitted to telemetry or step-down units instead of the CCU, the costs for evaluating admitted patients determined eventually not to have an ischemic etiology for their chest pain have been estimated to be on the order of 3 billion dollars.109 By analogy to the situation that occurs in EDs with patients who post hoc are felt not to need emergent care, it is not difficult to imagine that in an effort to reduce costs, third party payers may potentially deny payment for patients admitted for chest pain of possible ischemic etiology found to have negative evaluations. Fortunately, the increased scrutiny utilized for admitting patients with chest pain coincides with improvements in technology to detect patients with ACS and those at highest risk for adverse outcomes.3, 61 In addition, many EDs are expanding their capabilities to include short-stay observation units for monitoring and stratifying chest pain patients at low risk for ACS,40, 140 avoiding the need for a full admission to the hospital with its associated higher costs.27, 38, 39, 104 Moreover, traditional techniques for risk stratification, such as exercise treadmill testing (ETT), nuclear perfusion imaging, echocardiography, and even coronary angiography, are being critically re-evaluated. Previously best validated in patients at moderate to high risk for coronary artery disease (CAD),24 the focus is now on their diagnostic and prognostic value for a large, heterogeneous ED chest pain patient population that presents without clearly having ACS. During the past several years, cardiologists, ED physicians, and laboratorians, recognizing the increased intricacies of chest pain evaluation, have developed guidelines and consensus statements for assessing such patients and the use of traditional technologies.14, 110, 120, 135 Together, all of these factors have resulted in a multitude of diagnostic technologies, algorithms, and recommendations for the evaluation of the acute chest pain patient being presented to physicians. Recent studies on risk reduction in patients with CAD are also relevant to a discussion on evaluation of patients with chest pain. In addition to effective treatments for ACS, there are definitive data that modification of risk factors in patients with CAD can improve long-term outcomes.73, 117, 133 Thus, identification of as many patients as possible with underlying ischemic heart disease, irrespective of short-term risk, is a relevant goal. This article attempts to integrate both original data and the opinions from the several expert committees regarding the status of various techniques and technologies available to the clinician for both rapidly and accurately assessing patients for the presence and risk of ACS.