Robert S. Foote

A multicenter comparison of established and emerging cardiac biomarkers for the diagnostic evaluation of chest pain in the emergency department.

BACKGROUND The aim of this study is to assess the role of novel biomarkers for the diagnostic evaluation of acute coronary syndrome (ACS). METHODS Among 318 patients presenting to an emergency department with acute chest discomfort, we evaluated the diagnostic value of 5 candidate biomarkers (amino terminal pro-B-type natriuretic peptide [NT-proBNP], ischemia modified albumin, heart fatty acid binding protein, high-sensitivity troponin I [hsTnI], and unbound free fatty acids [FFAu]) for detecting ACS, comparing their results with that of conventional troponin T (cTnT). RESULTS Sixty-two subjects (19.5%) had ACS. The sensitivity and negative predictive values of NT-proBNP (73%, 90%) and hsTnI (57%, 89%) were higher than that of cTnT (22%, 84%). Unbound free fatty acids had the highest overall combination of sensitivity (75%), specificity (72%), and negative predictive values (92%) of all the markers examined. A significant increase in the C-statistic for cTnT resulted from the addition of results for NT-proBNP (change 0.09, P = .001), hsTnI (change 0.13, P < .001), and FFAu (change 0.15, P < .001). In integrated discrimination improvement and net reclassification improvement analyses, NT-proBNP, hsTnI, and FFAu added significant diagnostic information to cTnT; when changing the diagnostic criterion standard for ACS to hsTnI, FFAu still added significant reclassification for both events and nonevents. In serial sampling (n = 180), FFAu added important reclassification information to hsTnI. CONCLUSION Among emergency department patients with symptoms suggestive of ACS, neither ischemia modified albumin nor heart fatty acid binding protein detected or excluded ACS, whereas NT-proBNP, hsTnI, or FFAu added diagnostic information to cTnT. In the context of hsTnI results, FFAu measurement significantly reclassified both false negatives and false positives at baseline and in serial samples.

The challenge to the medical record.

Thirty years ago, not long after I began teaching firstand second-year medical students how to take patient medical histories and perform physical examinations, it occurred to me that I was trying to teach them how to write. I came to see that taking a medical history, performing a physical examination, reviewing ancillary data like electrocardiograms, laboratory results, and imagingstudies, and organizing this information into a coherent and useful document that could be recorded with a pen on paper—the now antique tools that were used at the time—is in fact a specialized form of the writing process. This process by its very nature forces the writer to do certain things that casual reflection on the same subject does not: organize, prioritize, and edit information;distinguish observation from assumption; recognize missing information and acquire it if possible; choose words that communicate clearly; and not only state conclusions but support them. The writer must take responsibility. The basic structure of the medical record has remained remarkably stable over many decades. This is no accident: it has the form it has because it reflects how clinicians think, and its internal structures help the clinician make sense of the disorderly flood of information and observation presented by every patient. It may be useful to recall the purposes of the medical record. First, it is an aid to memory, because each patient presents so many pieces of information that it is impossible to remember them all. Second, by the nature of its form, it forces the clinician to edit this information, organize it in a specific way, and present it in a specific order. Third, it communicates information to others caring for the patient. Fourth, it is a tool for teaching, since each medical record reveals not only the nature of the patient’s illness but also the thought process of the physician who created it. I would suggest that these 4 functions—recording, guiding thought, communicating, and teaching—are its primary purposes, and together they make the medical record a critically important tool in the achievement of the overall goal of medicine, namely, the care of the patient. The medical record is currently in the midst of a radical transformation, one driven by a number of coalescent factors. The most important of these is that the details of what was once a private encounter between patient and physician have become very important to many people who were not present when the encounter took place. Over the past few decades, as the American health care system has consumed an ever greater proportion of the gross national product and the processes by which this large amount of money is distributed have become more and more inscrutable, it has spawned a small army of people who “need” to know what happened in the examination room or at the bedside. They need to know because their livelihoods and the functioning of the system as a whole depend on it. This group includes administrators, policy makers, coders, support staff, information technologists, business groups, and government agencies, among many others. Preeminent among these groups are public and private third-party payers. These relatively new users of the medical record have been joined in a curious alliance by a second group consisting of people who wish to improve the medical record as a clinical tool. A central focus of both groups has been on increasing the use of electronic medical records (EMRs), a trend certain to be accelerated by recent federal legislation designed to speed adoption of EMRs. Clinical reformers favor EMRs for their potential to improve care, despite the paucity of evidence so far that this is the case, and nonclinical advocates favor them because they dramatically enhance the speed and thoroughness of their access to the medical records’ contents. Discussions of EMRs have tended to be dominated by descriptions of their potential benefits, while less attention has been paid to their potential hazards, among which are breaches of privacy, incompatibility of different systems, introduction of computer-based errors, and loss of productivity owing to cumbersome procedures that EMRs sometimes require. I think it behooves us as well to consider the impact of these systems on a very basic element of clinical practice, namely, how clinicians think. Some examples: the institution at which I practice recently adopted, at considerable cost, a proprietary EMR system. In addition to name and medical record number, the home page for each patient contains along its top and sides 68 tabs, many of which lead to numerous subtabs and links. Obstetrical, pediatric, and surgical fields are listed for every patient irrespective of sex, age, or whether surgery has ever occurred, as are subheadings for “Code Report” and “Transpo Sheet,” regardless of whether the patient has had a cardiac arrest or ever been “transpo’d” anywhere. Clearly, many of these tabs, fields, and menus are meant to address hypothetical circumstances of all generic patients and have nothing to do with the actual patient in question, and their presence contributes only distraction to the clinician. On consulting the “Notes” tab, one finds a chronological list of all notes written on the patient since the system was adopted—“all notes” in this case meaning all notes ever written by anyone, from physicians to physical therapists to secretaries. Locating the clinical notes can be difficult, and their admixture with numerous other notes interrupts the flow of narrative thought. The notes VIEWPOINT