Joni R. Beshansky

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.

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.

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.

Cost-effectiveness of the implantable cardioverter-defibrillator: effect of improved battery life and comparison with amiodarone therapy.

The implantable cardioverter-defibrillator (ICD) greatly reduces the incidence of sudden cardiac death among patients with recurrent sustained ventricular tachycardia and fibrillation who do not respond to conventional antiarrhythmic therapy. A cost-effectiveness analysis was performed, comparing the ICD, amiodarone and conventional agents. Actual variable costs of hospitalization and follow-up care were used for 21 ICD- and 43 amiodarone-treated patients. Life expectancy and total variable costs were predicted with use of a Markov decision analytic model. Clinical event rates and probabilities were based on published reports or expert opinion. Life expectancy with an ICD (6.1 years) was 50% greater than that associated with treatment with amiodarone (3.9 years) and 2.5 times that associated with conventional treatment (2.5 years). Assuming replacement every 24 months, ICD lifetime treatment costs (in 1989 dollars) for a 55-year old patient are expected to be

Patient-Specific Predictions of Outcomes in Myocardial Infarction for Real-Time Emergency Use: A Thrombolytic Predictive Instrument

89,600 compared with

Cost - Effectiueness of Streptokinase for Acute Myocardial Infarction A Combined Meta-analysis and Decision Analysis of the Effects of Infarct Location and of Likelihood of Infarction

24,800 for amiodarone and

Hospital mortality in women and men with acute cardiac ischemia: a prospective multicenter study.

16,100 for conventional therapy, yielding a marginal cost/effectiveness ratio for ICD versus amiodarone therapy of 1f429,200/year of life saved, which is comparable to that of other accepted medical treatments. If technologic improvements extend average battery life to 36 months, the marginal cost/effectiveness ratio would be

Implications of the mechanical (PCI) vs thrombolytic controversy for ST segment elevation myocardial infarction on the organization of emergency medical services: the Boston EMS experience.

21,800/year of life saved, and at 96 months it would be