Harry P. Selker

Missed Diagnoses of Acute Cardiac Ischemia in the Emergency Department

BACKGROUND Discharging patients with acute myocardial infarction or unstable angina from the emergency department because of missed diagnoses can have dire consequences. We studied the incidence of, factors related to, and clinical outcomes of failure to hospitalize patients with acute cardiac ischemia. METHODS We analyzed clinical data from a multicenter, prospective clinical trial of all patients with chest pain or other symptoms suggesting acute cardiac ischemia who presented to the emergency departments of 10 U.S. hospitals. RESULTS Of 10,689 patients, 17 percent ultimately met the criteria for acute cardiac ischemia (8 percent had acute myocardial infarction and 9 percent had unstable angina), 6 percent had stable angina, 21 percent had other cardiac problems, and 55 percent had noncardiac problems. Among the 889 patients with acute myocardial infarction, 19 (2.1 percent) were mistakenly discharged from the emergency department (95 percent confidence interval, 1.1 to 3.1 percent); among the 966 patients with unstable angina, 22 (2.3 percent) were mistakenly discharged (95 percent confidence interval, 1.3 to 3.2 percent). Multivariable analysis showed that patients who presented to the emergency department with acute cardiac ischemia were more likely not to be hospitalized if they were women less than 55 years old (odds ratio for discharge, 6.7; 95 percent confidence interval, 1.4 to 32.5), were nonwhite (odds ratio, 2.2; 1.1 to 4.3), reported shortness of breath as their chief symptom (odds ratio, 2.7; 1.1 to 6.5), or had a normal or nondiagnostic electrocardiogram (odds ratio, 3.3; 1.7 to 6.3). Patients with acute infarction were more likely not to be hospitalized if they were nonwhite (odds ratio for discharge, 4.5; 95 percent confidence interval, 1.8 to 11.8) or had a normal or nondiagnostic electrocardiogram (odds ratio, 7.7; 95 percent confidence interval, 2.9 to 20.2). For the patients with acute infarction, the risk-adjusted mortality ratio for those who were not hospitalized, as compared with those who were, was 1.9 (95 percent confidence interval, 0.7 to 5.2), and for the patients with unstable angina, it was 1.7 (95 percent confidence interval, 0.2 to 17.0). CONCLUSIONS The percentage of patients who present to the emergency department with acute myocardial infarction or unstable angina who are not hospitalized is low, but the discharge of such patients is associated with increased mortality. Failure to hospitalize is related to race, sex, and the absence of typical features of cardiac ischemia. Continued efforts to reduce the number of missed diagnoses are warranted.

Missed diagnoses of acute myocardial infarction in the emergency department: Results from a multicenter study

STUDY OBJECTIVE To determine the rate of missed acute myocardial infarction (AMI) in the emergency department and the factors related to missed diagnoses. STUDY DESIGN Observational and case-control study. SETTING Data were analyzed from a multicenter study of coronary care unit admitting practices that included patients who presented to the ED with chest pain or other symptoms suggestive of acute cardiac ischemia (N = 5,773). Patients with missed AMI (cases) were compared with control patients admitted with AMI and to a second control group of patients discharged without AMI. RESULTS Of 1,050 patients with AMI, 20 (1.9%; 95% confidence interval, 1.2-2.9%) were not admitted. Patients with missed AMI were significantly less likely to have ECG changes and a history of AMI or nitroglycerin use than patients admitted with AMI. However, they were significantly more likely to have ECG changes than patients discharged without AMI. Five patients with missed AMI (25%) had ST-segment elevation, and seven (35%) were discharged with a diagnosis of ischemic heart disease by the physician in the ED. Death or potentially lethal complications occurred in 25% of missed AMI patients. CONCLUSION The rate of missed AMI in the ED was only 1.9%. However, 25% of these might have been prevented had ST-elevation not been missed, and another 25% might have been prevented had patients who were recognized to have ischemic heart disease by the physician in the ED been admitted.

An Evaluation of Technologies for Identifying Acute Cardiac Ischemia in the Emergency Department: A Report from a National Heart Attack Alert Program Working Group

Abstract [Selker HP, Zalenski RJ, Antman EM, Aufderheide TP, Bernard SA, Bonow RO, Gibler WB, Hagen MD, Johnson P, Lau J, McNutt RA, Ornato J, Schwartz JS, Scott JD, Tunick PA, Weaver WD: An evaluation of technologies for identifying acute cardiac ischemia in the emergency department: A report from a National Heart Attack Alert Program Working Group. Ann Emerg Med January 1997;29:13-87.]

Sex-based differences in response to recombinant tissue plasminogen activator in acute ischemic stroke: a pooled analysis of randomized clinical trials.

Background and Purpose— Women experience worse outcomes after stroke compared with men. Prior work has suggested sex-based differences in coagulation and fibrinolysis markers in subjects with acute stroke. We explored whether sex might modify the effect of recombinant tissue plasminogen activator (rtPA) on outcomes in patients with acute ischemic stroke. Methods— Using a combined database including subjects from the National Institute of Neurological Disorders and Stroke (NINDS), Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) A and B, and the Second European Cooperative Acute Stroke Study (ECASS II) trials, we examined 90-day outcomes in patients randomized to rtPA versus placebo by sex. We used logistic regression to control for potential confounders. Results— Among 988 women treated between 0 and 6 hours from symptom onset, patients receiving rtPA were significantly more likely than those receiving placebo to have a modified Rankin Score ≤1 (40.5% versus 30.3%, P<0.0008). Among 1190 men, the trend toward benefit in the overall group did not reach statistical significance (38.5% versus 36.7%, P=0.52). An unadjusted analysis showed that women were significantly more likely to benefit from rtPA compared with men (P=0.04). Controlling for age, baseline National Institutes of Health Stroke Scale, diabetes, symptom onset to treatment time, prior stroke, systolic blood pressure, extent of hypoattenuation on baseline computed tomography scan and several significant interaction terms (including onset to treatment time–by-treatment and systolic blood pressure–by treatment) did not substantially change the strength of the interaction between gender and rtPA treatment (P=0.04). Conclusions— In this pooled analysis of rtPA in acute ischemic stroke, women benefited more than men, and the usual gender difference in outcome favoring men was not observed in the thrombolytic therapy group. For patients presenting at later time intervals, when the risks and benefits of rtPA are more finely balanced, sex may be an important variable to consider for patient selection.

Out-of-Hospital Administration of Intravenous Glucose-Insulin-Potassium in Patients With Suspected Acute Coronary Syndromes: The IMMEDIATE Randomized Controlled Trial

CONTEXT Laboratory studies suggest that in the setting of cardiac ischemia, immediate intravenous glucose-insulin-potassium (GIK) reduces ischemia-related arrhythmias and myocardial injury. Clinical trials have not consistently shown these benefits, possibly due to delayed administration. OBJECTIVE To test out-of hospital emergency medical service (EMS) administration of GIK in the first hours of suspected acute coronary syndromes (ACS). DESIGN, SETTING, AND PARTICIPANTS Randomized, placebo-controlled, double-blind effectiveness trial in 13 US cities (36 EMS agencies), from December 2006 through July 31, 2011, in which paramedics, aided by electrocardiograph (ECG)-based decision support, randomized 911 (871 enrolled) patients (mean age, 63.6 years; 71.0% men) with high probability of ACS. INTERVENTION Intravenous GIK solution (n = 411) or identical-appearing 5% glucose placebo (n = 460) administered by paramedics in the out-of-hospital setting and continued for 12 hours. MAIN OUTCOME MEASURES The prespecified primary end point was progression of ACS to myocardial infarction (MI) within 24 hours, as assessed by biomarkers and ECG evidence. Prespecified secondary end points included survival at 30 days and a composite of prehospital or in-hospital cardiac arrest or in-hospital mortality, analyzed by intent-to-treat and by presentation with ST-segment elevation. RESULTS There was no significant difference in the rate of progression to MI among patients who received GIK (n = 200; 48.7%) vs those who received placebo (n = 242; 52.6%) (odds ratio [OR], 0.88; 95% CI, 0.66-1.13; P = .28). Thirty-day mortality was 4.4% with GIK vs 6.1% with placebo (hazard ratio [HR], 0.72; 95% CI, 0.40-1.29; P = .27). The composite of cardiac arrest or in-hospital mortality occurred in 4.4% with GIK vs 8.7% with placebo (OR, 0.48; 95% CI, 0.27-0.85; P = .01). Among patients with ST-segment elevation (163 with GIK and 194 with placebo), progression to MI was 85.3% with GIK vs 88.7% with placebo (OR, 0.74; 95% CI, 0.40-1.38; P = .34); 30-day mortality was 4.9% with GIK vs 7.7% with placebo (HR, 0.63; 95% CI, 0.27-1.49; P = .29). The composite outcome of cardiac arrest or in-hospital mortality was 6.1% with GIK vs 14.4% with placebo (OR, 0.39; 95% CI, 0.18-0.82; P = .01). Serious adverse events occurred in 6.8% (n = 28) with GIK vs 8.9% (n = 41) with placebo (P = .26). CONCLUSIONS Among patients with suspected ACS, out-of-hospital administration of intravenous GIK, compared with glucose placebo, did not reduce progression to MI. Compared with placebo, GIK administration was not associated with improvement in 30-day survival but was associated with lower rates of the composite outcome of cardiac arrest or in-hospital mortality. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00091507.

Clinical Features of Emergency Department Patients Presenting with Symptoms Suggestive of Acute Cardiac Ischemia: A Multicenter Study

Identification of patients with acute cardiac ischemia (ACI) remains challenging. The object of this study was to examine the role of clinical findings in the diagnosis/triage of emergency department (ED) patients with symptoms suggestive of ACI. The study was designed as a secondary data analysis of a multicenter prospective controlled clinical trial. It was set in 10 midwest, southeast, and northeast U.S. hospitals, and 10,689 patients with chest pain or other symptoms suggesting ACI presenting from May 1993 to December 1993, participated. The results indicated that ACI patients were more likely to have chest pain as a chief complaint or presenting symptom (P = 0.001). The presenting symptom of nausea was more commonly associated with a final diagnosis of ACI (P = 0.003). Shortness of breath as the chief complaint and presenting symptoms of abdominal pain, nausea, dizziness, and fainting were less frequent among patients with a final diagnosis of ACI (P = 0.001). A past history of diabetes mellitus, myocardial infarction, or angina pectoris was more frequently associated with a final diagnosis of ACI (P = 0.001). A lower pulse rate in patients with a final diagnosis of ACI (P = 0.001) was not considered clinically significant. Median first and highest systolic blood pressures (SBPs) were higher, median lowest SBPs were lower, median diastolic blood pressure of the lowest SBPs were lower, and initial and highest pulse pressures were wider in patients with a final diagnosis of ACl (P = 0.001). On arrival, these blood pressure variables in AMI patients, subsequently classified as Killip class 4, were above the threshold for this classification. Rales were more commonly present in patients with a final diagnosis of ACI (P= 0.001). All primary ST-segment abnormalities, Q waves, and T-wave abnormalities, except T-wave flattening, were seen more frequently in patients with a final diagnosis ACI (P= 0.001). Normal ECGs were more frequently associated with a non-ACI final diagnosis, yet 20% of AMI patients and 37% of Unstable Angina Pectoris (UAP) patients had normal ECGs. It can be concluded that certain clinical features can help to identify ED patients with ACI. Initially normal ECGs can be seen in 20% of patients with AMI and 37% of patients with UAP. Patients with ACI can present with “normal” blood pressures and develop cardiogenic shock. Clinical outcome data for ACI patients are presented.

The Stroke–Thrombolytic Predictive Instrument A Predictive Instrument for Intravenous Thrombolysis in Acute Ischemic Stroke

Background and Purpose— Many patients with ischemic stroke eligible for recombinant tissue plasminogen activator (rt-PA) are not treated in part because of the risks and benefits perceived by treating physicians. Therefore, we aimed to develop a Stroke-Thrombolytic Predictive Instrument (TPI) to aid physicians considering thrombolysis for stroke. Methods— Using data from 5 major randomized clinical trials (n=2184) testing rt-PA in the 0- to 6-hour window, we developed logistic regression equations using clinical variables as potential predictors of a good outcome (modified Rankin Scale score ≤1) and of a catastrophic outcome (modified Rankin Scale score ≥5), with and without rt-PA. The models were internally validated using bootstrap re-sampling. Results— To predict good outcome, in addition to rt-PA treatment, 7 variables significantly affected prognosis and/or the treatment-effect of rt-PA: age, diabetes, stroke severity, sex, previous stroke, systolic blood pressure, and time from symptom onset. To predict catastrophic outcome, only age, stroke severity, and serum glucose were significant; rt-PA treatment was not. For patients treated within 3 hours, the median predicted probability of a good outcome with rt-PA was 42.9% (interquartile range [IQR]=18.6% to 64.7%) versus 25.3% (IQR=9.8% to 46.2%) without rt-PA; the median predicted absolute benefit was 12.5% (IQR=5.1% to 21.0%). The median probability for a catastrophic outcome, with or without, rt-PA was 15.2% (IQR=8.0% to 31.2%). The area under the receiver-operator characteristic curve was 0.788 for the model predicting good outcome and 0.775 for the model predicting bad outcome. Conclusions— The Stroke-TPI predicts good and bad functional outcomes with and without thrombolysis. Incorporated into a usable tool, it may assist in decision-making.

DO PATIENTS' CORONARY RISK FACTOR REPORTS PREDICT ACUTE CARDIAC ISCHEMIA IN THE EMERGENCY DEPARTMENT? A MULTICENTER STUDY

The objective of the present study was to determine whether the presence of the classical coronary risk factors increases the likelihood of acute cardiac ischemia beyond that expected from clinical presentation and electrocardiogram. Clinical data and reports of classical coronary risk factors were collected prospectively from 1743 patients without clinically obvious coronary disease. Patients were selected from 5773 emergency department patients at 6 hospitals who presented with symptoms suggesting acute ischemia. We used logistic regression to determine the relative risk of each risk factor report for acute ischemia. In women, the presence of classical risk factor reports does not increase the risk of acute ischemia. In men, only diabetes and family history of myocardial infarction significantly increase the risk (p less than 0.05). The relative risks are 2.4 and 2.1, respectively, and are small compared to those conferred by chest pain (12.1), an abnormal ST segment (8.7), or an abnormal T wave (5.3). For a patient presenting to the emergency department, the classical coronary risk factors convey minimal risk for acute cardiac ischemia, especially when compared to the overwhelming importance of the chief complaint and the ECG.

Women’s Ischemic Syndrome Evaluation Current Status and Future Research Directions: Report of the National Heart, Lung and Blood Institute Workshop: October 2–4, 2002 : Executive Summary

The WISE workshop was convened to review results from the Women’s Ischemic Syndrome Evaluation (WISE) study and other studies of ischemic heart disease to examine the nature and scope of gender differences in both chronic and acute cardiac ischemia, in terms of clinical manifestations, detection, and treatment. The purpose of the workshop was to provide recommendations to National Heart, Lung and Blood Institute that (1) address the need for improved diagnosis of ischemia and coronary artery disease (CAD) in women; (2) explore strategies for improved translation of promising research results into clinical practice; and (3) assess opportunities for effective educational strategies, including further refinement of the key messages for women with regard to risk factors and heart attack symptoms. CAD in women continues to be a major public health problem that represents a leading cause of death and disability.1–3 Among US women, more than a quarter of a million deaths per year are attributed to CAD, and this figure is expected to increase in the first decades of the 21st century as our population ages. The increased prevalence of obesity and diabetes in women is also expected to contribute to this increase in CAD. Women have a higher frequency of angina/chest pain than men; however, women have a lower prevalence of obstructive CAD compared with men with similar symptoms.4–6 Nevertheless, young women with obstructive CAD experience a significantly worse outcome compared with men with regard to prognosis after myocardial infarction,7 and older women with obstructive CAD often have …

The epidemiology of delays in a teaching hospital. The development and use of a tool that detects unnecessary hospital days.

This studys purpose was to develop a tool that detects, quantifies, and assigns causes for medically unnecessary hospital delays and use it to describe the epidemiology of delays at a teaching tertiary care hospital. Based on observational data, a taxonomy of delays was constructed that included nine major categories and 166 subcategories. This formed the basis for an instrument for detecting inefficiency in hospital care: the Delay Tool. Initially designed for real-time concurrent assessment, in retrospective use it was also reliable, requiring about 6 minutes per medical record. In using the Delay Tool over a 6-month period on general internal medical and gastrointestinal services, it was discovered that 30% of 960 patients experienced delays, the average length of which was 2.9 days. This represented 17% of all hospital days. The most frequent causes of delays were scheduling of tests (31%), unavailability of post-discharge facilities (18%), physician decision-making (13%), discharge planning (12%), and scheduling of surgery (12%). Because of the longer lengths of the delays involved with awaiting postdischarge facilities (primarily nursing home beds), this was the most important cause of delays and represented 41% of all delay days. The general medicine and gastrointestinal services had significantly different distributions of delay types related to their different kinds of patients and care. The Delay Tool should be helpful in addressing hospital, and hospital-related, inefficiencies in health care delivery.