A clinical decision rule to identify which chest pain patients can safely be removed from cardiac monitoring in the emergency department

The HEART score to identify emergency department patients suspected of an acute coronary syndrome who can be removed from cardiac monitoring: A retrospective chart review

OBJECTIVE

Continuous cardiac monitoring has been recommended for ED patients being evaluated for possible acute coronary syndrome (ACS) due to concern for arrhythmia, although evidence suggests this risk is low. Indiscriminate use of monitored beds restricts access for other critically unwell patients and contributes to overcrowding. The objective of the present study was to determine if a low/intermediate-risk HEART score identified patients at very low risk for a clinically important arrhythmia who could be removed from cardiac monitoring.

METHODS

This was a single centre, retrospective, cohort study of consecutive ED patients in a tertiary referral hospital evaluated for possible ACS from July to August 2017. Patients with ST-elevation myocardial infarction or an arrhythmia at presentation which would mandate monitoring were excluded. Data was obtained by medical chart review. The primary outcome was the occurrence of an arrhythmia requiring treatment while in ED.

RESULTS

Inter-rater reliability for data extraction demonstrated very strong agreement (kappa 0.87, 95% confidence interval 0.83-0.91). There were 653 participants included with 83 (12.7%) having a final diagnosis of ACS. Three (0.5%) clinically important arrhythmias occurred. There were no cases of ventricular tachycardia, ventricular fibrillation or cardiac arrest. Five hundred and forty (82.7%) participants were low/intermediate-risk HEART score and one (0.2%) clinically important arrhythmia occurred (this was supraventricular tachycardia treated by a valsalva manoeuvre).

CONCLUSION

Among ED patients presenting with a possible ACS, a low/intermediate-risk HEART score identified those at very low risk for having a clinically important arrhythmia while in ED.

Prospective validation of a clinical decision rule to identify patients presenting to the emergency department with chest pain who can safely be removed from cardiac monitoring

BACKGROUND

Most patients with chest pain in the emergency department are assigned to cardiac monitoring for several hours, blocking access for patients in greater need. We sought to validate a previously derived decision rule for safe removal of patients from cardiac monitoring after initial evaluation in the emergency department.

METHODS

We prospectively enrolled adults (age ≥ 18 yr) who presented with chest pain and were assigned to cardiac monitoring at 2 academic emergency departments over 18 months. We collected standardized baseline characteristics, findings from clinical evaluations and predictors for the Ottawa Chest Pain Cardiac Monitoring Rule: whether the patient is currently free of chest pain, and whether the electrocardiogram is normal or shows only nonspecific changes. The outcome was an arrhythmia requiring intervention in the emergency department or within 8 hours of presentation to the emergency department. We calculated diagnostic characteristics for the clinical prediction rule.

RESULTS

We included 796 patients (mean age 63.8 yr, 55.8% male, 8.9% admitted to hospital). Fifteen patients (1.9%) had an arrhythmia, and the rule performed with the following characteristics: sensitivity 100% (95% confidence interval [CI] 78.2%-100%) and specificity 36.4% (95% CI 33.0%-39.6%). Application of the Ottawa Chest Pain Cardiac Monitoring Rule would have allowed 284 out of 796 patients (35.7%) to be safely removed from cardiac monitoring.

INTERPRETATION

We successfully validated the decision rule for safe removal of a large subset of patients with chest pain from cardiac monitoring after initial evaluation in the emergency department. Implementation of this simple yet highly sensitive rule will allow for improved use of health care resources.

Discrepancy between clinician and research assistant in TIMI score calculation (TRIAGED CPU)

Introduction

Several studies have attempted to demonstrate that the Thrombolysis in Myocardial Infarction (TIMI) risk score has the ability to risk stratify emergency department (ED) patients with potential acute coronary syndromes (ACS). Most of the studies we reviewed relied on trained research investigators to determine TIMI risk scores rather than ED providers functioning in their normal work capacity. We assessed whether TIMI risk scores obtained by ED providers in the setting of a busy ED differed from those obtained by trained research investigators.

Methods

This was an ED-based prospective observational cohort study comparing TIMI scores obtained by 49 ED providers admitting patients to an ED chest pain unit (CPU) to scores generated by a team of trained research investigators. We examined provider type, patient gender, and TIMI elements for their effects on TIMI risk score discrepancy.

Results

Of the 501 adult patients enrolled in the study, 29.3% of TIMI risk scores determined by ED providers and trained research investigators were generated using identical TIMI risk score variables. In our low-risk population the majority of TIMI risk score differences were small; however, 12% of TIMI risk scores differed by two or more points.

Conclusion

TIMI risk scores determined by ED providers in the setting of a busy ED frequently differ from scores generated by trained research investigators who complete them while not under the same pressure of an ED provider.

A description of nurses' decision-making in managing electrocardiographic monitor alarms

AIMS AND OBJECTIVES

To describe the cues and factors that nurses use in their decision-making when responding to clinical alarms.

BACKGROUND

Alarms are designed to be very sensitive, and as a result, they are not very specific. Lack of adherence to the practice standards for electrocardiographic monitoring in hospital settings has been observed, resulting in overuse of the electrocardiographic monitoring. Monitoring without consideration of clinical indicators uses scarce healthcare resources and may even produce untoward circumstances because of alarm fatigue. With so many false alarms, alarm fatigue represents a symptom of a larger problem. It cannot be fixed until all of the factors that contribute to its existence have been examined.

DESIGN

This was a qualitative descriptive study.

METHOD

This study was conducted at an academic medical centre located in the Northeast United States. Eight participants were enrolled using purposive sampling. Nurses were observed for two three-hour periods. Following each observation, the nurse was interviewed using the critical decision method to describe the cognitive processes related to the alarm activities. Qualitative data from the conducted interviews were analysed via an a priori framework founded in the critical decision method.

RESULTS

This study reveals information, experience, guidance and decision-making as the four prominent categories contributing to nurses' decision-making in relation to alarm management. Managing technology was a category not identified a priori that emerged in the data analysis.

CONCLUSION

Nurses revealed a breadth of information needed to adequately identify and interpret monitor alarms, and how they used that information to put the alarms into the particular context of an individual patient's situations.

RELEVANCE TO CLINICAL PRACTICE

Understanding the cues and factors nurses use when responding to cardiac alarms will guide the development of learning experiences and inform policies to guide practice.

Impact of a decision rule on duration of continuous cardiac monitoring of patients with suspected acute coronary syndrome in an emergency department

BACKGROUND/AIMS

To determine the effect of introducing a decision rule on the duration of continuous cardiac monitoring (CCM) for patients with suspected acute coronary syndrome in an adult emergency department (ED).

METHODS

This was a retrospective observational study of 220 patients with suspected acute coronary syndrome made up of two consecutive cohorts collected before and after introduction in July 2010 of a decision rule that made use of a new high-sensitivity troponin T assay. The primary outcome was median CCM duration in the ED (CCMED). Secondary outcomes were median duration of CCM in the first 24 h, rate of adverse events, proportion of patients after the intervention who had the rule adhered to, and estimated median CCMED had the decision rule been adhered to by all patients.

RESULTS

The decision rule was adhered to in 59.3% (95% confidence interval 49.8-68.1) of patients post-intervention. There was no statistically or clinically significant difference in median CCMED before (240 min, interquartile range 156-313) and after (230 min interquartile range 145-353) introduction of the decision rule (P = 0.74) nor in CCM in the first 24 h (908 min vs 929 min). Seven (3.2%, 95% confidence interval 1.4-6.6) adverse events occurred overall. All three patients with adverse events after the intervention were monitored in ED according to the decision rule.

CONCLUSION

Introduction of this decision rule did not decrease the median CCMED. All adverse events after the intervention occurred in appropriately monitored patients, including patients with initially negative high-sensitivity troponin T, suggesting that the decision rule would not compromise patient safety.

Is telemetry useful in evaluating chest pain patients in an observation unit?

Since the development of coronary care units (CCUs), telemetry has rapidly become the standard of care in evaluating patients with suspected acute coronary syndromes, regardless of the probability for ischemia. However, there is no data to support this practice. Our objective was to evaluate the utility of routine cardiac monitoring in a chest pain observation unit. We prospectively studied the utility of routine cardiac monitoring in 249 consecutive patients admitted to an observation unit in an academic Emergency Department over a 6-month period. All the patients presented with chest pain thought to be cardiac ischemia. Observation included serial cardiac enzymes, ECG cardiac monitoring, and exercise testing in a designated chest pain observation unit. These patients were determined to be at low risk for an acute coronary event by two criteria: first, the symptoms had resolved by the time of observation unit admission, and second, the initial ECG was normal, unchanged or non-diagnostic for acute ischemia. Adverse outcomes included cardiac arrest, hospital admission secondary to cardiac dysrhythmia, or alteration in the patient's medical therapy upon discharge from the observation unit, secondary to cardiac dysrhythmia. There were 249 patients included with a median age of 52 with 60% women. Fifteen percent of the patients were, subsequently, admitted to the hospital for further evaluation of ischemia based on enzyme, ECG, and exercise testing results. One patient with known Tachy-Brady syndrome was noted to have 1.5-2 s pauses while sleeping, and discharged with instructions to hold beta blocker therapy pending results of a continuous loop recorder. Of the remaining 248 patients, no patient suffered a cardiac arrest, no patient was admitted to the hospital secondary to cardiac dysrhythmia, and no alteration in a patient's medical therapy was made secondary to cardiac dysrhythmia. No patient returned to the Emergency Department within 72 h with cardiac arrest, acute dysrhythmia or acute myocardial infarction. Although telemetry may be the standard of care in evaluating the patients with suspected acute coronary syndromes, regardless of the probability of an acute ischemic syndrome, in those patients with a normal or non diagnostic ECG and resolved symptoms, routine cardiac monitoring is unnecessary.

Exploitation of resources and cardiovascular outcomes in low-risk patients with chest pain hospitalized in coronary care units

Background

Most patients who present to medical centers due to chest pain do not suffer from acute coronary syndromes and do not need to be hospitalized in coronary care units (CCUs). This study was done to determine exploitation of resources and cardiovascular outcomes in low-risk patients with chest pain hospitalized in CCUs of educational hospitals affiliated with a major medical university.

Methods

Over a 4-month period, 550 patients with chest pain who were hospitalized in the CCUs belonging to six hospitals affiliated to the authors’ medical university were recruited by census method. Using Thrombolysis in Myocardial Infarction risk score, 95 patients (17.27%) were categorized as low-risk patients. This group was evaluated with respect to demographics, bed occupancy rate, mean hospitalization period, expenses during admission, and cardiovascular outcomes in the 30-day period postdischarge.

Results

Mean (± standard deviation) hospitalization duration was 3.04 (±0.71) days. No significant difference was seen between the six surveyed hospitals regarding hospitalization duration (P = 0.602). The highest bed occupancy rate was seen in Taleghani and Shohada Tajrish hospitals and the lowest was in Modarres Hospital. The mean paid treatment expenses by low-risk patients was IRR 2,050,000 (US$205). Mean total hospitalization expenses was US$205. No significant difference was seen between the six surveyed hospitals (P = 0.699). Of the patients studied, 89.5% did not show any cardiovascular complications in 1 month and no deaths occurred.

Conclusion

Given the high bed-occupancy rate by low-risk patients, associated high hospitalization costs, and the lack of cardiovascular complications in patients observed at 1-month follow-up after discharge, it is recommended that appropriate evaluations be performed in emergency units to prevent unnecessary admissions.

Diagnosing acute coronary syndrome in primary care: comparison of the physicians' risk estimation and a clinical decision rule

BACKGROUND

Diagnosing acute coronary syndrome (ACS) in a primary care setting poses a diagnostic dilemma for physicians.

OBJECTIVE

We directly compared the diagnostic accuracy of a clinical decision rule (CDR) based on history taking and physical examination in suspected ACS with the risk estimates of the attending GP.

METHODS

In a prospective multicenter study, patients suspected of ACS were included by the GP. GPs were asked to estimate the probability (0%-100%) of the presence of ACS. GPs collected patient data, but they were not aware of the CDR and did not score the patient accordingly.

RESULTS

Two hundred and ninety-eight patients were included (52% female, mean age 66 years, 22% ACS). The area under the receiver operating characteristic (ROC) curve (AUC) was 0.75 [95% confidence interval (CI) 0.68-0.82] for the GP risk estimate and 0.66 (95% CI 0.58-0.73) for the CDR. There was an agreement between the risk estimation of the GP and a CDR in 51% and the prevalence of ACS in predefined low-, intermediate- and high-risk groups was similar for the GP and CDR estimates. In the low-risk group, according to the GP, four patients (8.2%) suffered an ACS. These four patients were all identified by the decision rule as high risk.

CONCLUSIONS

The GP classified patients as ACS or no ACS more adequately than the CDR, judged by the AUC. However, the use of a CDR in patients that are considered at low risk for ACS by the GP could reduce the amount of missed myocardial infarctions.

Ruling out coronary heart disease in primary care patients with chest pain: a clinical prediction score

BACKGROUND

Chest pain raises concern for the possibility of coronary heart disease. Scoring methods have been developed to identify coronary heart disease in emergency settings, but not in primary care.

METHODS

Data were collected from a multicenter Swiss clinical cohort study including 672 consecutive patients with chest pain, who had visited one of 59 family practitioners' offices. Using delayed diagnosis we derived a prediction rule to rule out coronary heart disease by means of a logistic regression model. Known cardiovascular risk factors, pain characteristics, and physical signs associated with coronary heart disease were explored to develop a clinical score. Patients diagnosed with angina or acute myocardial infarction within the year following their initial visit comprised the coronary heart disease group.

RESULTS

The coronary heart disease score was derived from eight variables: age, gender, duration of chest pain from 1 to 60 minutes, substernal chest pain location, pain increasing with exertion, absence of tenderness point at palpation, cardiovascular risks factors, and personal history of cardiovascular disease. Area under the receiver operating characteristics curve was of 0.95 with a 95% confidence interval of 0.92; 0.97. From this score, 413 patients were considered as low risk for values of percentile 5 of the coronary heart disease patients. Internal validity was confirmed by bootstrapping. External validation using data from a German cohort (Marburg, n = 774) revealed a receiver operating characteristics curve of 0.75 (95% confidence interval, 0.72; 0.81) with a sensitivity of 85.6% and a specificity of 47.2%.

CONCLUSIONS

This score, based only on history and physical examination, is a complementary tool for ruling out coronary heart disease in primary care patients complaining of chest pain.

ALaRMED: adverse events in low-risk chest pain patients receiving continuous ECG monitoring in the emergency department: a survey of Canadian emergency physicians

OBJECTIVE

Current guidelines suggest that most patients who present to an emergency department (ED) with chest pain should be placed on a continuous electrocardiographic monitoring (CEM) device. We surveyed emergency physicians to determine their perception of current occupancy rates of CEM and to assess their attitudes toward prescribing monitors for low-risk chest pain patients in the ED.

METHODS

We conducted a cross-sectional, self-administered Internet and mail survey of a random sample of 300 members of the Canadian Association of Emergency Physicians. Main outcome measures included the perceived frequency of fully occupied monitors in the ED and physicians' willingness to forgo CEM in certain chest pain patients.

RESULTS

The response rate was 66% (199 respondents). The largest group of respondents (43%; 95% confidence interval [CI] 36%-50%) indicated that monitors were fully occupied 90%-100% of the time during their most recent ED shift. When asked how often they were forced to choose a patient for monitor removal because of the limited number of monitors, 52% (95% CI 45%-60%) of respondents selected 1-3 times per shift. Ninety percent (95% CI 84%-93%) of respondents indicated that they would forgo CEM in certain cardiac chest pain patients if there was good evidence that the risk of a monitor-detected adverse event was very low.

CONCLUSION

Emergency physicians report that monitors are often fully occupied in Canadian EDs, and most are willing to forgo CEM in certain chest pain patients. A large prospective study of CEM in low-risk chest pain patients is warranted.