Performance of a population-based cardiac risk stratification tool in Asian patients with chest pain.

OBJECTIVES: Most contemporary cardiac risk stratification tools have been derived and validated in mixed-race populations. Their validity in single-race populations has not been tested. The authors sought to compare the performance of a risk stratification tool between a mixed-race U.S. patient population and an Asian patient population. METHODS: This study is an analysis of data from the Internet Tracking Registry for Acute Coronary Syndromes (i(*)trACS) registry of patients with chest pain presenting to the emergency departments of eight U.S. centers and one site in Singapore. The Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) was computed for included patients, and its performance in predicting acute coronary syndrome (ACS) was compared between patients from the United States and Singapore. RESULTS: Of the 11,991 included patients, 1,120 experienced ACS. Although the ACI-TIPI demonstrated similar accuracy among groups (area under the curve, 0.729 [U.S.] vs. 0.719 [Singapore]; p = 0.5611), sensitivity and specificity were different when equal ACI-TIPI thresholds were considered. Recreating the logistic regression models used to create the ACI-TIPI showed similar results between the derived parameters and the parameters estimated for the U.S. group. In contrast, age older than 50 years (log-odds ratio [LOR], 0.107; 95% confidence interval [CI] = 0.518 to 0.713), male gender (LOR, 0.487; 95% CI = 0.149 to 1.122), and chest pain as a primary complaint (LOR, 0.237; 95% CI = 0.139 to 0.613) had little predictive power in patients from Singapore. CONCLUSIONS: Differences exist in presentation and factors associated with ACS among patients from the United States and Singapore that may affect the performance of risk stratification tools. These findings suggest that cardiac clinical decision rules need international validation.

Is the initial diagnostic impression of "noncardiac chest pain" adequate to exclude cardiac disease?

STUDY OBJECTIVE: In patients presenting to the emergency department (ED) with an initial diagnostic impression of noncardiac chest pain, we determine the 30-day incidence of adverse cardiac events and characteristics associated with those events. METHODS: The multicenter, prospectively collected Internet Tracking Registry for Acute Coronary Syndromes (i*tr ACS ) registry of patients with chest pain enrolled from June 1, 1999, to August 1, 2001, was reviewed. We included patients if the physician's initial diagnostic impression was noncardiac chest pain after the medical history, physical examination, and initial 12-lead ECG. ED records, inpatient records, and follow-up results were reviewed for evidence of an adverse cardiac event defined as ST-segment or non-ST-segment elevation myocardial infarction, unstable angina, revascularization, or cardiac death within 30 days. RESULTS: Of 17,737 patients enrolled in i*tr ACS , 2,992 had an initial emergency physician impression of noncardiac chest pain. Of these, 85 (2.8%) patients had definite evidence for an adverse cardiac event. The adverse cardiac event group was older (61.2 versus 47.9 years), more likely to be men (58.6% versus 38.7%), and had a higher Acute Cardiac Ischemia-Time Insensitive Predictive Instrument score (26.1 versus 15.6). Factors associated with adverse cardiac events included hypercholesterolemia, diabetes, history of coronary artery disease, and history of congestive heart failure. CONCLUSION: When the initial impression is noncardiac chest pain, high-risk features such as traditional cardiovascular risk factors or a history of coronary artery disease are associated with adverse cardiac events. In the absence of well-defined criteria, treating physicians should consider further evaluation before diagnosing patients with noncardiac chest pain if these features are present.

Insurance status and the treatment of myocardial infarction at academic centers.

UNLABELLED: Numerous studies have documented treatment disparities in patients with acute coronary syndromes based on race and gender. Other causes for treatment disparities may exist. OBJECTIVES: To determine if insurance status affects quality of care in patients with acute myocardial infarction (AMI) presenting to academic health centers. METHODS: The Internet Tracking Registry for Acute Coronary Syndromes (i*trACS), a prospective multicenter registry of patients with chest pain presenting to the emergency department who receive an electrocardiogram, was used as the database (N = 17,737). A subset of patients who were diagnosed as having AMI were selected from the database (n = 936). Patients were classified as having either ST-segment elevation MI (n = 178) or non-ST-segment elevation MI (n = 758). Insurance status, age, race, and gender were extracted as predictor variables. The influence of predictor variables on treatment modality was investigated using logistic regression, adjusted for clustering within sites. RESULTS: The odds of a self-pay patient with ST-segment elevation MI receiving fibrinolytics were 3.23 (95% CI = 1.56 to 6.69) times higher than for other patients. Patients with Medicare coverage were less likely to receive fibrinolytics (odds ratio [OR] 0.35, 95% CI = 0.19 to 0.65) and tended to undergo percutaneous coronary intervention less often (OR 0.60, 95% CI = 0.36 to 1.01). The odds of a privately insured patient's receiving coronary artery bypass grafting (OR 2.76, 95% CI = 1.62 to 4.72) or percutaneous coronary intervention (OR 1.47, 95% CI = 1.03 to 2.11) were higher than for other patients. CONCLUSIONS: Insurance coverage appears to affect treatment in patients with AMI, with self-pay patients more likely to receive less-expensive therapies and insured patients more likely to receive invasive treatments.

Tetanus immunity and physician compliance with tetanus prophylaxis practices among emergency department patients presenting with wounds.

STUDY OBJECTIVE: We determine tetanus seroprotection rates and physician compliance with tetanus prophylaxis recommendations among patients presenting with wounds. METHODS: A prospective observational study of patients aged 18 years or older who presented to 5 university-affiliated emergency departments (EDs) because of wounds was conducted between March 1999 and August 2000. Serum antitoxin levels were measured by enzyme immunoassay with seroprotection defined as more than 0.15 IU/mL. Seroprotection rates, risk factors for lack of seroprotection, and rates of physician compliance with tetanus prophylaxis recommendations by the Advisory Committee on Immunization Practices were determined. RESULTS: The seroprotection rate among 1,988 patients was 90.2% (95% confidence interval 88.8% to 91.5%). Groups with significantly lower seroprotection rates were persons aged 70 years or older, 59.5% (risk ratio [RR] 5.2); immigrants from outside North America or Western Europe, 75.3% (RR 3.7); persons with a history of inadequate immunization, 86.3% (RR 2.9); and persons without education beyond grade school, 76.5% (RR 2.5). Despite a history of adequate immunization, 18% of immigrants lacked seroprotection. Overall, 60.9% of patients required tetanus immunization, of whom 57.6% did not receive indicated immunization. Among patients with tetanus-prone wounds, appropriate prophylaxis (ie, tetanus immunoglobulin and toxoid) was provided to none of 504 patients who gave a history of inadequate primary immunization (of whom 15.1% had nonprotective antibody titers) and to 218 (79%) of 276 patients who required only a toxoid booster. CONCLUSION: Although seroprotection rates are generally high in the United States, the risk of tetanus persists in the elderly, immigrants, and persons without education beyond grade school. There is substantial underimmunization in the ED (particularly with regard to use of tetanus immunoglobulin), leaving many patients, especially those from high-risk groups, unprotected. Better awareness of tetanus prophylaxis recommendations is necessary, and future tetanus prophylaxis recommendations may be more effective if they are also based on demographic risk factors.

Can electrocardiographic criteria predict adverse cardiac events and positive cardiac markers?

OBJECTIVES: To determine electrocardiogram (ECG) predictors of positive cardiac markers and short-term adverse cardiac events in an undifferentiated chest pain population presenting to emergency departments (EDs). The authors hypothesized that specific ECG findings, other than those previously identified in higher-risk populations, would be predictive of cardiac outcomes and positive cardiac markers. METHODS: This study used data from a prospectively collected, retrospectively analyzed Internet-based data registry of undifferentiated chest pain patients (i*trACS). Logistic regression modeling was performed to determine the ECG findings that were predictive of 1) positive cardiac markers and 2) short-term adverse cardiac events. RESULTS: ST-segment elevation (STE), ST-segment depression (STD), pathological Q-waves (PQW), and T-wave inversion were associated with increased odds of percutaneous coronary intervention or catheterization, myocardial infarction, or coronary artery bypass grafting. The odds of creatine kinase-MB (CK-MB) measuring positive were increased if STE, STD, or PQW were present [odds ratio (OR) 2.495, 2.582, and 1.295, respectively]. A right bundle branch block tended to decrease the odds of CK-MB measuring positive (OR 0.658). A similar pattern of results was observed for troponin I (OR 3.608 for STE, 3.72 for STD, 1.538 for PQW). Troponin T showed an increased odds of measuring positive if any of STE, STD, left bundle branch block, or T-wave inversion were evident (OR 2.313, 2.816, 1.80, and 1.449, respectively). CONCLUSIONS: Initial ECG criteria can be used to predict short-term cardiac outcomes and positive cardiac markers. These findings can be important aids in the risk-stratification and aggressive treatment regimens of chest pain patients presenting to EDs.