Cardiac Ischemia Time-Insensitive Predictive Instrument Research Articles

ED Chest Pain Rules: Follow Your HEART?

ED Chest Pain Rules: Follow Your HEART?

An example of medical device-based projection of clinical trial enrollment: Use of electrocardiographic data to identify candidates for a trial in acute coronary syndromes.

To identify potential participants for clinical trials, electronic health records (EHRs) are searched at potential sites. As an alternative, we investigated using medical devices used for real-time diagnostic decisions for trial enrollment. To project cohorts for a trial in acute coronary syndromes (ACS), we used electrocardiograph-based algorithms that identify ACS or ST elevation myocardial infarction (STEMI) that prompt clinicians to offer patients trial enrollment. We searched six hospitals' electrocardiograph systems for electrocardiograms (ECGs) meeting the planned trial's enrollment criterion: ECGs with STEMI or > 75% probability of ACS by the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI). We revised the ACI-TIPI regression to require only data directly from the electrocardiograph, the e-ACI-TIPI using the same data used for the original ACI-TIPI (development set n = 3,453; test set n = 2,315). We also tested both on data from emergency department electrocardiographs from across the US (n = 8,556). We then used ACI-TIPI and e-ACI-TIPI to identify potential cohorts for the ACS trial and compared performance to cohorts from EHR data at the hospitals. Receiver-operating characteristic (ROC) curve areas on the test set were excellent, 0.89 for ACI-TIPI and 0.84 for the e-ACI-TIPI, as was calibration. On the national electrocardiographic database, ROC areas were 0.78 and 0.69, respectively, and with very good calibration. When tested for detection of patients with > 75% ACS probability, both electrocardiograph-based methods identified eligible patients well, and better than did EHRs. Using data from medical devices such as electrocardiographs may provide accurate projections of available cohorts for clinical trials.

Telemetry Monitoring: Are Admission Criteria Based on Evidence?

Telemetry Monitoring: Are Admission Criteria Based on Evidence?

Study design for the Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency Care (IMMEDIATE) Trial: A double-blind randomized controlled trial of intravenous glucose, insulin, and potassium for acute coronary syndromes in emergency medical services

Experimental studies suggest that metabolic myocardial support by intravenous (IV) glucose, insulin, and potassium (GIK) reduces ischemia-induced arrhythmias, cardiac arrest, mortality, progression from unstable angina pectoris to acute myocardial infarction (AMI), and myocardial infarction size. However, trials of hospital administration of IV GIK to patients with ST-elevation myocardial infarction (STEMI) have generally not shown favorable effects possibly because of the GIK intervention taking place many hours after ischemic symptom onset. A trial of GIK used in the very first hours of ischemia has been needed, consistent with the timing of benefit seen in experimental studies. The IMMEDIATE Trial tested whether, if given very early, GIK could have the impact seen in experimental studies. Accordingly, distinct from prior trials, IMMEDIATE tested the impact of GIK (1) in patients with acute coronary syndromes (ACS), rather than only AMI or STEMI, and (2) administered in prehospital emergency medical service settings, rather than later, in hospitals, after emergency department evaluation. The IMMEDIATE Trial was an emergency medical service-based randomized placebo-controlled clinical effectiveness trial conducted in 13 cities across the United States that enrolled 911 participants. Eligible were patients 30 years or older for whom a paramedic performed a 12-lead electrocardiogram to evaluate chest pain or other symptoms suggestive of ACS for whom electrocardiograph-based acute cardiac ischemia time-insensitive predictive instrument indicated a ≥75% probability of ACS, and/or the thrombolytic predictive instrument indicated the presence of a STEMI, or if local criteria for STEMI notification of receiving hospitals were met. Prehospital IV GIK or placebo was started immediately. Prespecified were the primary end point of progression of ACS to infarction and, as major secondary end points, the composite of cardiac arrest or in-hospital mortality, 30-day mortality, and the composite of cardiac arrest, 30-day mortality, or hospitalization for heart failure. Analyses were planned on an intent-to-treat basis, on a modified intent-to-treat group who were confirmed in emergency departments to have ACS, and for participants presenting with STEMI. The IMMEDIATE Trial tested whether GIK, when administered as early as possible in the course of ACS by paramedics using acute cardiac ischemia time-insensitive predictive instrument and thrombolytic predictive instrument decision support, would reduce progression to AMI, mortality, cardiac arrest, and heart failure. It also tested whether it would provide clinical and pathophysiologic information on GIK's biological mechanisms.

Prognostic utility of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI)

BackgroundWe sought to evaluate the test characteristics of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) in relation to 30-day major adverse cardiac events (MACE) among patients who presented to the Emergency Department with symptoms suggestive of an acute coronary syndrome. We then examined the test characteristics of various dichotomous ACI-TIPI cut points.MethodsWe prospectively recruited a cohort of Emergency Department (ED) patients with acute chest pain at two urban university hospitals between June and September 2006. Upon enrollment, baseline demographics and cardiac risk factors were collected. An electrocardiogram (ECG) was performed and analyzed with the built-in ACI-TIPI multiple regression model software. An ACI-TIPI probability score was recorded for each patient. Diagnostic test characteristics of ACI-TIPI for MACE (non-ST elevation myocardial infarction (NSTEMI), percutaneous coronary intervention, coronary artery bypass grafting, and all-cause mortality) within 30 days were determined.ResultsOf 144 patients enrolled (mean age 59.1 ± 14.1 years, 59% men), 19 (13%) patients suffered MACE within 30 days. Receiver-operating characteristics (ROC) for ACI-TIPI yielded a c-statistic of 0.69 (95% CI 0.59-0.80, p < 0.01). An ACI-TIPI score of ≥ 20 had 100% sensitivity (95% CI 82-100), 100% negative predictive value (95% CI 86-100), and 21% specificity (14-31%).ConclusionsThese preliminary results suggest that, while ACI-TIPI has limited discriminatory value for MACE overall, a score of < 20 may have 30-day prognostic utility to allow for safe outpatient management in patients with acute chest pain.

Emergency Medical Service Predictive Instrument–Aided Diagnosis and Treatment of Acute Coronary Syndromes and ST-segment Elevation Myocardial Infarction in the IMMEDIATE Trial

Background. A challenge for emergency medical service (EMS) is accurate identification of acute coronary syndromes (ACS) and ST-segment elevation myocardial infarction (STEMI) for immediate treatment and transport. The electrocardiograph-based acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) and the thrombolytic predictive instrument (TPI) have been shown to improve diagnosis and treatment in emergency departments (EDs), but their use by paramedics in the community has been less studied. Objective. To identify candidates for participation in the Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency Care (IMMEDIATE) Trial, we implemented EMS use of the ACI-TIPI and the TPI in out-of-hospital electrocardiographs and evaluated its impact on paramedic on-site identification of ACS and STEMI as a community-based approach to improving emergency cardiac care. Methods. Ambulances in the study municipalities were outfitted with electrocardiographs with ACI-TIPI and TPI software. Using a before–after quasi-experimental design, in Phase 1, for seven months, paramedics were provided with the ACI-TIPI/TPI continuous 0–100% predictions automatically printed on electrocardiogram (ECG) text headers to supplement their identification of ACS; in Phase 2, for 11 months, paramedics were told to identify ACS based on an ACI-TIPI cutoff probability of ACS ≥ 75% and/or TPI detection of STEMI. In Phase 3, this cutoff approach was used in seven additional municipalities. Confirmed diagnoses of ACS, acute myocardial infarction (AMI), and STEMI were made by blinded physician review for 100% of patients. Results. In Phase 1, paramedics identified 107 patients as having ACS; in Phase 2, 104. In Phase 1, 45.8% (49) of patients so identified had ACS confirmed, which increased to 76.0% (79) in Phase 2 (p < 0.001). Of those with ACS, 59.2% (29) had AMI in Phase 1 versus 84.8% (67) with AMI in Phase 2 (p < 0.01), and STEMI was confirmed in 40.8% (20) versus 68.4% (54), respectively (p < 0.01). In Phase 3, of 226 patients identified by paramedics as having ACS, 74.3% (168) had ACS confirmed, of whom 81.0% (136) had AMI and 65.5% (110) had STEMI. Among patients with ACS, the proportion who received percutaneous coronary intervention (PCI) was 30.6% (15) in Phase 1, increasing to 57.0% (45) in Phase 2 (p < 0.004) and 50.6% (85) in Phase 3, and the proportions of patients with STEMI receiving PCI rose from 75.0% (15) to 83.3% (45) (p < 0.4) and 82.7% (91). Conclusions. In a wide range of EMS systems, use of electrocardiographs with ACI-TIPI and TPI decision support using a 75% ACI-TIPI cutoff improves paramedic diagnostic performance for ACS, AMI, and STEMI and increases the proportions of patients who receive PCI. Key words: acute coronary syndromes; acute myocardial infarction; electrocardiology; emergency medical service; clinical decision support.

Early Cardiac Catheterization Laboratory Activation by Paramedics for Patients with ST-segment Elevation Myocardial Infarction on Prehospital 12-Lead Electrocardiograms

Background. Prompt reperfusion in ST-segment elevation myocardial infarction (STEMI) saves lives. Although studies have shown that paramedics can reliably interpret STEMI on prehospital 12-lead electrocardiograms (p12ECGs), prehospital activation of the cardiac catheterization laboratory by emergency medical services (EMS) has not yet gained widespread acceptance. Objective. To quantify the potential reduction in time to percutaneous coronary intervention (PCI) by early prehospital activation of the cardiac catheterization laboratory in STEMI. Methods. This prospective, observational study enrolled all patients diagnosed with STEMI by paramedics in a mid-sized regional EMS system. Patients were enrolled if: 1) the paramedic interpreted STEMI on the p12ECG, 2) the Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) score was 75%% or greater, and 3) the patient was transported to either of two area PCI centers. Data recorded included the time of initial EMS “STEMI alert” from the scene, time of arrival at the emergency department (ED), and time of actual catheterization laboratory activation by the ED physician, all using synchronized clocks. The primary outcome measure was the time difference between the STEMI alert and the actual activation (i.e., potential time savings). The false-positive rate (patients incorrectly diagnosed with STEMI by paramedics) was also calculated and compared with a locally accepted false-positive rate of 10%%. Results. Twelve patients were enrolled prior to early termination of the study. The mean and median potential time reductions were 15 and 11 minutes, respectively (range 7–29 minutes). There was one false STEMI alert (8.3%% false-positive rate) for a patient with a right bundle branch block who subsequently had a non–ST-segment elevation myocardial infarction. The study was terminated when our cardiologists adopted a prehospital catheterization laboratory activation protocol based on our initial data. Conclusion. Important reductions in time to reperfusion seem possible by activation of the catheterization laboratory by EMS from the scene, with an acceptably low false-positive rate in this small sample. This type of clinical research can inform multidisciplinary policies and bring about meaningful clinical practice changes.

37: Utility of Acute Cardiac Ischemia Time-Insensitive Predictive Instrument in the Chest Pain Observation Unit

To evaluate if the Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) is associated with outcomes for emergency department (ED) patients in the chest pain observation unit (CPU).

Acute cardiac ischemia time-insensitive predictive instrument predicts exercise treadmill test results in the chest pain unit

Acute cardiac ischemia time-insensitive predictive instrument predicts exercise treadmill test results in the chest pain unit

Triage and Diagnosis of Chest Pain in Rural Hospitals: Implementation of the ACI-TIPI in the High Plains Research Network

The Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) has been shown to improve diagnostic accuracy of acute cardiac ischemia (ACI) and decrease coronary care unit admissions in urban emergency departments. The purpose of this study was to determine the impact of the ACI-TIPI on triage and diagnosis of patients with chest pain in rural hospitals. We undertook a controlled trial of the impact ACI-TIPI use in the High Plains Research Network (HPRN). Main outcome measures were the triage of patients in emergency departments (admission, transfer, or discharge home) and diagnostic accuracy. There were 1,861 patients seen during a 10-month period. Forty-five percent of all patients complaining of chest pain were discharged home from the emergency department. Eight percent were transferred from the emergency department, and another 10% were transferred later after admission. Among patients with acute myocardial infarction or unstable angina, 22.2% were transferred directly from the emergency department and only 3% were discharged home when ACI-TIPI was available, compared with 18.7% transferred and 5.2% discharged home when not available (P = .4). Diagnostic accuracy was high and not statistically different with the addition of the ACI-TIPI score (86.8% ACI-TIPI off vs 89.0% ACI-TIPI on, P = .15), Physicians in the HPRN provided appropriate diagnosis and triage to patients with chest pain. Routine addition of the ACI-TIPI score did not improve diagnostic accuracy or significantly change triage. Further research on ACI-TIPI in rural hospitals is necessary before recommending routine use of the ACI-TIPI.

The Potential of Training to Increase Acceptance and Use of Computerized Decision Support Systems for Medical Diagnosis

The goals of this study were to understand the reasons underlying the limited use of medical decision-support tools and to explore the potential of a computer-based tutorial to mitigate barriers to use. Medical decision-support tools such the Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) have demonstrated statistical validity and clinical impact for patient safety but have seen limited adoption and use. The study developed a brief Web-based "demystifying" ACI-TIPI tutorial employing case-based training and evaluated the effectiveness of that tutorial in changing self-reported attitudes and behaviors. Clinicians using the tutorial reported greater understanding of how to use the ACI-TIPI score appropriately and increased confidence in the score. Case studies in the tutorial that provided examples of how to use the score for actual cases were rated as especially helpful. This study suggests that a primary barrier to the use of statistical decision support tools for patient diagnosis is lack of training or experience in combining a population-based numerical risk score with other diagnostic information about the individual patient's case that is not considered in that score. The results of this study indicate that there is a potential for a relatively brief tutorial to increase acceptance and use of decision support tools for medical diagnosis. These findings have the potential for the identification of methods to help clinicians learn how to use statistical and probabilistic information to better assess risk and to promote integration of decision support tools into medical decision making for improvement of patient safety.

Performance of a Population-based Cardiac Risk Stratification Tool in Asian Patients with Chest Pain

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. 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. 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. 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.

Use of the Acute Cardiac Ischemia Time-Insensitive Predictive Instrument to Predict Outcomes in the Emergency Department Chest Pain Unit

Use of the Acute Cardiac Ischemia Time-Insensitive Predictive Instrument to Predict Outcomes in the Emergency Department Chest Pain Unit

Diagnostic accuracy of Computer-Assisted Database-Derived pretest probability assessment for acute coronary syndrome

Study objectives: We determine the diagnostic accuracy of a noninvasive clinical screening instrument for the detection of acute coronary syndrome (ACS) in emergency department (ED) patients. The screening instrument is composed of clinical data input into a computer to estimate the probability of ACS. Methods: We aim to enroll 1,000 patients with complete data who were observed in an ED chest pain evaluation unit at Carolinas Medical Center, Duke University, and the University of California–Davis, and prospectively collect data to determine the pretest probability (PTP) of ACS for each patient using 3 methods of PTP assessment: (1) a computer-assisted, database-derived method; (2) the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) method; and (3) physician estimate to the nearest 1%. This information will be used to compare which method of PTP assessment categorizes the highest percentage of patients as being very low risk for ACS (ie, PTP Results: We completed enrollment on August 1, 2004, and follow-up and adjudication of outcomes continues. We enrolled a total of 1,154 patients and expect to obtain valid follow-up in 85% of subjects. Complete pretest probability are data available for 723 patients. Only 12 (1.6%) patients with a positive outcome were identified. The mean (median) pretest probability estimates by the 3 methods were 5.2% (4.0%) for physician estimate, 6.4% (4.3%) for attribute matching, and 13.6% (9.9%) for ACI-TIPI. The percentage of all patients estimated to have a pretest probability of ACS of less than 2% was 19% (95% confidence interval [CI] 16% to 22%) for clinicians, 34% (95% CI 31% to 38%) for attribute-matching, and 9% (95% CI 7% to 12%) for ACI-TIPI. No patient with a pretest probability of less than 2% estimated by any of the 3 methods developed ACS. Conclusion: At interim analysis, the rate of positive outcomes for ACS was unexpectedly low in this sample of patients evaluated in ED chest pain units. Attribute matching categorized significantly more patients as having a very low pretest probability compared with clinician estimate or ACI-TIPI.

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

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. 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. 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. 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.

The development and role of predictive instruments in acute coronary events: improving diagnosis and management.

The diagnosis and management of acute myocardial infarction and unstable angina pectoris are frequent challenges for emergency department staff. Strategies must quickly and accurately identify all patients requiring admission, monitoring, and reperfusion therapy to maximize outcomes without overdiagnosing. The Acute Cardiac Ischemia Time-Insensitive Predictive Instrument and the Thrombolytic Predictive Instrument are two decision-support tools designed to address this need. The instruments have been shown to improve some measures of the appropriateness of and time to emergency department triage. Prospective trials will be completed soon that will examine their effects on morbidity and mortality.

Acute cardiac ischemia in patients with cocaine-associated complaints: Results of a multicenter trial*1

<h2>Abstract</h2> <b>Study Objective:</b> To describe the characteristics of a large group of patients who presented to emergency departments with cocaine-associated symptoms consistent with acute cardiac ischemia (ACI) and to determine the incidence of confirmed ACI including acute myocardial infarction (AMI) in this population. <b>Methods:</b> We performed a substudy on all patients in a multicenter prospective clinical trial (the Acute Cardiac Ischemia–Time Insensitive Predictive Instrument [ACI-TIPI] Clinical Trial) that enrolled ED patients with chest pain or other symptoms consistent with ACI including subjects with identified cocaine use. Demographic and clinical features, including initial and follow-up clinical data, ECGs, and tests to determine serum creatine kinase isoenzyme MB subunit concentrations, were analyzed. Diagnoses of AMI followed the World Health Organization criteria for AMI and of angina pectoris, the Canadian Cardiovascular Society Classification. <b>Results:</b> Of the 10,689 patients enrolled in the trial, 293 (2.7%) had cocaine-associated complaints. Among the 10 participating hospitals, the incidence of patients with cocaine-associated symptoms varied from 0.3% to 8.4%. Only 6 patients (2.0%, 95% confidence interval [CI] 0.76% to 4.4%) had a diagnosis of ACI; 4 (1.4%, 95% CI 0.37% to 3.5%) had unstable angina, and 2 (0.7%, 95% CI 0.08% to 2.4%) had AMI. Although patients with cocaine-induced complaints were as likely to be admitted to the coronary care unit compared with all study patients without cocaine use (14% versus 18%, <i>P</i> =.14, difference not significant), these patients were much less likely to have confirmed unstable angina (1.4% versus 9.3%, <i>P</i> <.001) or AMI (0.7% versus 8.6%, <i>P</i> <.001). Compared with patients younger than 45 years, patients with cocaine usage were more likely to be admitted to the ICU (14% versus 8.0%, <i>P</i> =.0018) but less likely to have confirmed AMI (0.7% versus 2.8%, <i>P</i> =.033). <b>Conclusion:</b> Patients presenting to EDs with cocaine-associated chest pain or related symptoms infrequently had ACI, and even less so, AMI. This suggests the need for selectivity in the hospitalization of patients with such cocaine-associated symptoms. [Feldman JA, Fish SS, Beshansky JR, Griffith JL, Woolard RH, Selker HP. Acute cardiac ischemia in patients with cocaine-associated complaints: results of a multicenter trial. <i>Ann Emerg Med.</i> November 2000;36:469-476.]

Pretest probability assessment for selective rest sestamibi scans in stable chest pain patients

The objective of this study was to determine whether pretest probability assessments permit more selective testing of chest pain patients with technetium-99m sestamibi scanning. Pretest probabilities of cardiac ischemia were measured both objectively (Acute Cardiac Ischemia Time-Insensitive Predictive Instrument [ACI-TIPI]) and subjectively (physician's estimate of the probability of unstable angina). Two groups were defined: patients whose postsestamibi scan led to a “downgrade” of the intensity of monitoring and those that resulted in no change in monitoring intensity. Sixty-five patients met study criteria; 25 had a disposition downgrade and 40 had no change. Pretest ACI-TIPI scores were similar in the two groups (29% ± 18% versus 27% ± 11%, mean ± standard deviation; P = .95) as were the physician's assessment of unstable angina (39% ± 22% versus 40% ± 24%; P = .75). Objective or subjective pretest probabilities are not significantly different in patients who are likely to have their disposition altered by sestamibi scanning. (Am J Emerg Med 2000;18:789-792.

Acute cardiac ischemia in patients with cocaine-associated complaints: Results of a multicenter trial

Study Objective: To describe the characteristics of a large group of patients who presented to emergency departments with cocaine-associated symptoms consistent with acute cardiac ischemia (ACI) and to determine the incidence of confirmed ACI including acute myocardial infarction (AMI) in this population. Methods: We performed a substudy on all patients in a multicenter prospective clinical trial (the Acute Cardiac Ischemia–Time Insensitive Predictive Instrument [ACI-TIPI] Clinical Trial) that enrolled ED patients with chest pain or other symptoms consistent with ACI including subjects with identified cocaine use. Demographic and clinical features, including initial and follow-up clinical data, ECGs, and tests to determine serum creatine kinase isoenzyme MB subunit concentrations, were analyzed. Diagnoses of AMI followed the World Health Organization criteria for AMI and of angina pectoris, the Canadian Cardiovascular Society Classification. Results: Of the 10,689 patients enrolled in the trial, 293 (2.7%) had cocaine-associated complaints. Among the 10 participating hospitals, the incidence of patients with cocaine-associated symptoms varied from 0.3% to 8.4%. Only 6 patients (2.0%, 95% confidence interval [CI] 0.76% to 4.4%) had a diagnosis of ACI; 4 (1.4%, 95% CI 0.37% to 3.5%) had unstable angina, and 2 (0.7%, 95% CI 0.08% to 2.4%) had AMI. Although patients with cocaine-induced complaints were as likely to be admitted to the coronary care unit compared with all study patients without cocaine use (14% versus 18%, P =.14, difference not significant), these patients were much less likely to have confirmed unstable angina (1.4% versus 9.3%, P <.001) or AMI (0.7% versus 8.6%, P <.001). Compared with patients younger than 45 years, patients with cocaine usage were more likely to be admitted to the ICU (14% versus 8.0%, P =.0018) but less likely to have confirmed AMI (0.7% versus 2.8%, P =.033). Conclusion: Patients presenting to EDs with cocaine-associated chest pain or related symptoms infrequently had ACI, and even less so, AMI. This suggests the need for selectivity in the hospitalization of patients with such cocaine-associated symptoms. [Feldman JA, Fish SS, Beshansky JR, Griffith JL, Woolard RH, Selker HP. Acute cardiac ischemia in patients with cocaine-associated complaints: results of a multicenter trial. Ann Emerg Med. November 2000;36:469-476.]

Association of acute cardiac ischemia time-insensitive predictive instrument results with disease and test outcomes in emergency department chest pain observation unit patients

Association of acute cardiac ischemia time-insensitive predictive instrument results with disease and test outcomes in emergency department chest pain observation unit patients