Syncope in the Emergency Department

Utility of serial troponin testing for emergency department patients with syncope

BACKGROUND

For emergency department (ED) patients with syncope, cardiac troponin can identify acute coronary syndrome (ACS) and prognosticate for 30-day serious adverse events. However, it is unclear if serial testing improves diagnostic yield and prognostication.

METHODS

This was a secondary analysis of data from two prospective studies conducted to develop the Canadian Syncope Risk Score. Adults (age ≥ 16 years) with syncope were enrolled, and patient characteristics, vital signs, physician diagnostic impression, electrocardiogram and troponin results, and adjudicated 30-day serious adverse event were collected. The primary outcome was the detection of a serious adverse event within 30 days of ED disposition. The secondary outcome was comparison of ED length of stay among patients with single versus serial troponin measurements.

RESULTS

4996 patients [mean age 64.5 (SD 18.8) years, 52.2% male] were included: 4397 (89.8%) with single troponin [232 (5.3%) with serious adverse event in the ED and 203 (4.6%) after ED disposition]; 499 (10.2%) patients with > 1 troponin measurement [39 (7.8%) with serious adverse event in ED and 60 (12.0%) after ED disposition]. Among those with serial measurements, 10 patients (2.0%) had a rise from below to above the 99th percentile threshold, of whom 4 patients (0.8%) suffered serious adverse event: two with arrhythmias diagnosed on electrocardiogram, one with ACS and one suffered respiratory failure. Nine patients (1.8%) had Canadian Syncope Risk Score risk reclassification based on serial measurement, and none suffered 30-day serious adverse event. Median ED length of stay was significantly longer for patients with serial testing (5.6 vs. 3.8 h, p < 0.001).

CONCLUSIONS

The initial troponin measurement was sufficient for serious adverse event detection and in-ED risk stratification. Serial troponin testing does not improve the diagnostic yield or prognostication and should be reserved for patients with ongoing symptoms or electrocardiogram findings suggestive of cardiac ischemia.

The syncope core management process in the emergency department: a consensus statement of the EUSEM syncope group

The European Society of Cardiology issued updated syncope guidelines in 2018 which included recommendations for managing syncope in the emergency department (ED) setting. However, these guidelines lack detailed process-oriented instructions regarding the fact that ED syncope patients initially present with a transient loss of consciousness (TLOC), which can have a broad spectrum of causes. This study aims to establish a European consensus on the general process of the workup and care for patients with suspected syncope and provides rules for sufficient and systematic management of the broad group of syncope (initially presenting as TLOC) patients in the ED. A variety of European diagnostic and therapeutic standards for syncope patients were reviewed and summarized in three rounds of a modified Delphi process by the European Society for Emergency Medicine syncope group. Based on a consensus statement, a detailed process pathway is created. The primary outcome of this work is the presentation of a universal process pathway for the structured management of syncope patients in European EDs. The here presented extended event process chain (eEPC) summarizes and homogenizes the process management of European ED syncope patients. Additionally, an exemplary translation of the eEPC into a practice-based flowchart algorithm, which can be used as an example for practical use in the ED, is provided in this work. Syncope patients, initially presenting with TLOC, are common and pose challenges in the ED. Despite variations in process management across Europe, the development of a universally applicable syncope eEPC in the ED was successfully achieved. Key features of the consensus and eEPC include ruling out life-threatening causes, distinguishing syncope from nonsyncopal TLOCs, employing syncope risk stratification categories and based on this, making informed decisions regarding admission or discharge.

Assessing the Predictive Value of Combining Risk Scoring Systems and Ultrasonography for Short-Term Adverse Outcomes in Syncope: A Prospective Observational Study

BACKGROUND

In the emergency department (ED), the role of ultrasonography (USG) in risk stratification and predicting adverse events in syncope patients is a current research area. However, it is still unclear how ultrasound can be combined with existing risk scores.

OBJECTIVES

In this study, it was aimed to examine the contribution of the use of bedside USG to current risk scores in the evaluation of patients presenting to the ED with syncope. The predictive values of the combined use of USG and risk scores for adverse outcomes at 7 and 30 days were examined.

METHODS

The Canadian Syncope Risk Score (CSRS), San Francisco syncope rules (SFSR), USG findings of carotid and deep venous structures, and echocardiography results were recorded for patients presenting with syncope. Parameters showing significance in the 7-day and 30-day adverse outcome groups were utilized to create new scores termed CSRS-USG and SFSR-USG. Predictive values were evaluated using receiver operating characteristic (ROC) analysis. The difference between the predictive values was evaluated with the DeLong test.

RESULTS

The study was carried out with 137 participants. Adverse outcomes were observed in 45 participants (32.8%) within 30 days. 32 (71.7%) of the adverse outcomes were in the first 7 days. For 30-day adverse outcomes, the SFSR-USG (p = 0.001) and CSRS-USG (p = 0.038) scores had better predictive accuracy compared to SFSR and CSRS, respectively. However, there was no significant improvement in sensitivity and specificity values.

CONCLUSION

The use of USG in the evaluation of syncope patients did not result in significant improvement in sensitivity and specificity values for predicting adverse events. However, larger sample-sized studies are needed to understand its potential contributions better.

Interhospital variability in hospital admissions for patients with low-risk syncope presenting to the emergency department

Background

Guidelines and risk scores have sought to standardize the management of syncope in the emergency department (ED), but variation in practice remains.

Objective

The purpose of this study was to explore factors associated with admission for patients presenting to the ED with low-risk syncope.

Methods

Our study population included adult patients in the Nationwide Emergency Department Sample between 2006 and 2019 who presented to an ED with a primary diagnosis of syncope. Multivariable hierarchical logistic regression analyses determined the association of patient or hospital factors with admission. Reference effect measures methodology assessed the relative contributions of patient, hospital, and unmeasured hospital factors.

Results

Of the 3,206,739 qualifying encounters during the study period, 804,398 (25.1%) met low-risk criteria. Of these patients, 20,260 were admitted to the hospital (2.5%). Factors associated with increased odds of admission included increasing age and weekend presentation to the hospital, while female sex, lack of medical insurance, hospital region, teaching status, and higher ED volume decile were associated with lower odds of admission. Reference effect measures methodology demonstrated that unmeasured site variability contributed the widest range of odds for admission (odds ratio [OR] 5th percentile vs 95th percentile 0.23-4.38) compared with the composite patient (OR 0.33-3.68) or hospital (OR 0.65-1.30) factors.

Conclusion

Admission patterns for low-risk syncope varies widely across institutions. Unmeasured site variation contributes significantly to the variability in admission rates, suggesting which hospital a patient presents to plays a disproportionate role in admission decisions. Further guidance to reduce practice variation in syncope care in the ED is needed.

[Syncopes - differential diagnoses and treatment]

Syncope is a sudden loss of consciousness (transient loss of consciousness, TLOC) caused by a lack of cerebral perfusion that resolves spontaneously and completely after a short period of time 1. With a lifetime prevalence of 40% and constituting about 1% of all emergency department admissions, syncope is a common and medically relevant problem 2 3. The underlying causes of syncope are diverse and associated with significantly different prognoses. A structured approach is essential to identify high-risk patients and ensure appropriate treatment. This article aims at providing an overview of the current recommendations for the diagnosis and treatment of syncope.

Developing Implementation Strategies to Support the Uptake of a Risk Tool to Aid Physicians in the Clinical Management of Patients With Syncope: Systematic Theoretical and User-Centered Design Approach

BACKGROUND

The Canadian Syncope Risk Score (CSRS) was developed to improve syncope management in emergency department settings. Evidence-based tools often fail to have the intended impact because of suboptimal uptake or poor implementation.

OBJECTIVE

In this paper, we aimed to describe the process of developing evidence-based implementation strategies to support the deployment and use of the CSRS in real-world emergency department settings to improve syncope management among physicians.

METHODS

We followed a systematic approach for intervention development, including identifying who needs to do what differently, identifying the barriers and enablers to be addressed, and identifying the intervention components and modes of delivery to overcome the identified barriers. We used the Behaviour Change Wheel to guide the selection of implementation strategies. We engaged CSRS end users (ie, emergency medicine physicians) in a user-centered design approach to generate and refine strategies. This was achieved over a series of 3 qualitative user-centered design workshops lasting 90 minutes each with 3 groups of emergency medicine physicians.

RESULTS

A total of 14 physicians participated in the workshops. The themes were organized according to the following intervention development steps: theme 1-identifying and refining barriers and theme 2-identifying the intervention components and modes of delivery. Theme 2 was subdivided into two subthemes: (1) generating high-level strategies and developing strategies prototypes and (2) refining and testing strategies. The main strategies identified to overcome barriers included education in the format of meetings, videos, journal clubs, and posters (to address uncertainty around when and how to apply the CSRS); the development of a web-based calculator and integration into the electronic medical record (to address uncertainty in how to apply the CSRS); a local champion (to address the lack of team buy-in); and the dissemination of evidence summaries and feedback through email communications (to address a lack of evidence about impact).

CONCLUSIONS

The ability of the CSRS to effectively improve patient safety and syncope management relies on broad buy-in and uptake across physicians. To ensure that the CSRS is well positioned for impact, a comprehensive suite of strategies was identified to address known barriers.

Pharmacologic prevention of recurrent vasovagal syncope: A systematic review and network meta-analysis of randomized controlled trials

Vasovagal syncope (VVS) is a transient loss of consciousness that currently imposes a high burden on health care systems with limited evidence of the comparative efficacy of available pharmacologic interventions. This study aims to compare all pharmacologic therapies suggested in randomized controlled trials (RCTs) through systematic review and network meta-analysis. A systematic search in PubMed, Embase, Web of Science, and Cochrane Library was conducted to identify RCTs evaluating pharmacologic therapies for patients with VVS. The primary outcome was spontaneous VVS recurrence. The secondary outcome was a positive head-up tilt test (HUTT) after receiving intervention, regarded as a lower level of evidence. Pooled risk ratio (RR) with 95% confidence interval (CI) was calculated using random-effect network meta-analysis. Pairwise meta-analysis for comparison with placebo was also performed when applicable. The surface under the cumulative ranking curve analysis was conducted to rank the treatments for each outcome. Twenty-eight studies with 1744 patients allocated to different medications or placebo were included. Network meta-analysis of the reduction in the primary outcome showed efficacy for midodrine (RR 0.55; 95% CI 0.35-0.85) and fluoxetine (especially in patients with concomitant anxiety) (RR 0.36; 95% CI 0.16-0.84). In addition, midodrine and atomoxetine were superior to other treatment options, considering positive HUTT (RR 0.37; 95% CI 0.23-0.59; and RR 0.49; 95% CI 0.28-0.86, respectively). Overall, midodrine was the only agent shown to reduce spontaneous syncopal events. Fluoxetine also seems to be beneficial but should be studied further in RCTs. Our network meta-analysis did not find evidence of the efficacy of any other medication.

Counter pressure maneuvers for syncope prevention: A semi-systematic review and meta-analysis

Physical counter pressure maneuvers (CPM) are movements that are recommended to delay or prevent syncope (fainting) by recruiting the skeletal muscle pump to augment cardiovascular control. However, these recommendations are largely based on theoretical benefit, with limited data evaluating the efficacy of CPM to prevent syncope in the real-world setting. We conducted a semi-systematic literature review and meta-analysis to assess CPM efficacy, identify literature gaps, and highlight future research needs. Articles were identified through a literature search (PubMed, April 2022) of peer-reviewed publications evaluating the use of counter pressure or other lower body maneuvers to prevent syncope. Two team members independently screened records for inclusion and extracted data. From 476 unique records identified by the search, 45 met inclusion criteria. Articles considered various syncopal conditions (vasovagal = 12, orthostatic hypotension = 8, postural orthostatic tachycardia syndrome = 1, familial dysautonomia = 2, spinal cord injury = 1, blood donation = 10, healthy controls = 11). Maneuvers assessed included hand gripping, leg fidgeting, stepping, tiptoeing, marching, calf raises, postural sway, tensing (upper, lower, whole body), leg crossing, squatting, “crash” position, and bending foreword. CPM were assessed in laboratory-based studies (N = 28), the community setting (N = 4), both laboratory and community settings (N = 3), and during blood donation (N = 10). CPM improved standing systolic blood pressure (+ 14.8 ± 0.6 mmHg, p < 0.001) and heart rate (+ 1.4 ± 0.5 bpm, p = 0.006), however, responses of total peripheral resistance, stroke volume, or cerebral blood flow were not widely documented. Most patients experienced symptom improvement following CPM use (laboratory: 60 ± 4%, community: 72 ± 9%). The most prominent barrier to employing CPM in daily living was the inability to recognize an impending faint. Patterns of postural sway may also recruit the skeletal muscle pump to enhance cardiovascular control, and its potential as a discrete, proactive CPM needs further evaluation. Physical CPM were successful in improving syncopal symptoms and producing cardiovascular responses that may bolster against syncope; however, practical limitations may restrict applicability for use in daily living.

Performance of the American Heart Association/American College of Cardiology/Heart Rhythm Society versus European Society of Cardiology guideline criteria for hospital admission of patients with syncope

BACKGROUND

Current American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS) and European Society of Cardiology (ESC) guidelines recommend different strategies to avoid low-yield admissions in patients with syncope.

OBJECTIVE

The purpose of this study was to directly compare the safety and efficacy of applying admission criteria of both guidelines to patients presenting with syncope to the emergency department in 2 multicenter studies.

METHODS

The international BASEL IX (BAsel Syncope EvaLuation) study (median age 71 years) and the U.S. SRS (Improving Syncope Risk Stratification in Older Adults) study (median age 72 years) were investigated. Primary endpoints were sensitivity/specificity for the adjudicated diagnosis of cardiac syncope (BASEL IX only) and 30-day major adverse cardiovascular events (30d-MACE).

RESULTS

Among 2560 patients in the BASEL IX and 2085 in SRS studies, ACC/AHA/HRS and ESC criteria recommended admission for a comparable number of patients in BASEL IX (27% vs 28%), but ACC/AHA/HRS criteria less often in SRS (19% vs 32%; P <.01). Recommendations were discordant in ∼25% of patients. In BASEL IX, sensitivity for cardiac syncope and 30d-MACE among patients without admission criteria was comparable for ACC/AHA/HRS and ESC criteria (64% vs 65%, P = .86; and 67% vs 71%, P = .15, respectively). In SRS, sensitivity for 30d-MACE was lower with ACC/AHA/HRS (54%) vs ESC criteria (88%; P <.001). Similarly, specificity for cardiac syncope and 30d-MACE in BASEL IX was comparable for both guidelines, but in SRS the ACC/AHA/HRS guidelines showed a higher specificity for 30d-MACE than the ESC guidelines.

CONCLUSION

ACC/AHA/HRS and ESC guidelines showed disagreement regarding admission for 1 in 4 patients and had only modest sensitivity, all indicating possible opportunities for improvements.

The Characteristics of Syncope-Related Emergency Department Visits: Resource Utilization and Admission Rate Patterns in Emergency Departments

Background and objective

Decision-making about syncope patients presenting to the emergency department (ED) is challenging since physicians must balance the minimal risks of life-threatening conditions with the unessential use of expensive imaging or unnecessary hospitalizations. This study aimed to determine the characteristics of ED visits, resource utilization, and admission rate patterns related to syncope in the United States (US) during the period 2005-2015.

Methods

Data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) on ED visits during the 11-year period from 2005 to 2015 were retrieved. ED visits for syncope were identified and compared against non-syncope ED visits. The demographic and clinical characteristics of patients, as well data on resource allocation and admission trends were captured and described for the syncope and the non-syncope groups.

Results

Syncope accounted for 1.11% of the total ED visits during the study period from 2005 to 2015. The incidence of syncope-related ED visits was higher among elderly females, whites, and non-Hispanics. The trend of admission rates showed a decline from about 30% in 2005-2010 to less than 20% in 2014 and 2015. Advanced imaging (CT or MRI) was ordered for 34% of syncope patients.

Conclusion

The percentage of syncope-related ED visits remained stable during the study period, but the admission rates declined while the use of advanced imaging in syncope-related ED visits remained substantially high despite the advances in research and availability of clinical guidelines. Future research is needed to rationalize healthcare utilization in syncope-related ED visits and precisely identify the high-risk population.

Nurse triage accuracy in the evaluation of syncope according to European Society of Cardiology guidelines

AIMS

The role of triage for patients admitted to the emergency department (ED) for a syncopal transitory loss of consciousness (TLOC) has not been debated, and no comparisons with the recent European Society of Cardiology (ESC) guidelines are currently available. To verify the ability of triage to correctly prioritize patients with syncopal TLOC.

METHODS AND RESULTS

All patients who received a triage assessment at the ED of the Merano Hospital (Italy) between 1 January 2017 and 30 June 2019 for a syncope were considered. All syncope were reclassified according to the aetiology reported in the ESC guidelines. The baseline characteristics of the patients were recorded and divided according to the severity code provided during triage into two study groups: high priority (red/orange) and low priority (yellow/green/blue). The outcome of the study was the presence of a diagnosed cardiac cause within 30 days after the admission. A total of 2066 patients were enrolled (14.3% high priority vs. 85.7% low priority). Cardiac syncope was present in 7.5% of patients. Nurse triage showed a sensitivity for cardiac syncope of 44.8%, a specificity of 88.1%, and an accuracy of 84.9%. The observed discriminatory ability presented an area under the receiver operating characteristic curve of 0.685 (95% confidence interval 0.638-0.732). The possible identification of the aetiology of the syncopal TLOC by the nurse showed good agreement with the medical diagnosis (Cohen's kappa 0.857, P < 0.001).

CONCLUSIONS

In cases of syncopal TLOC, nurse triage had a fair specificity but suboptimal sensitivity for cardiac causes. Specific nursing assessments following triage (e.g. precise scores or electrocardiogram) could improve the triage performance.

Current best practices in emergency evaluation and management of syncope

ABSTRACT

Syncope is a common medical presentation that can cost the US healthcare system up to $2.4 billion dollars annually. Much of this cost can be mitigated with proper evaluation and management in the urgent care setting, as well as appropriate use of a risk stratification system.

A Rational Evaluation of the Syncope Patient: Optimizing the Emergency Department Visit

Syncope accounts for up to 2% of emergency department visits and results in the hospitalization of 12–86% of patients. There is often a low diagnostic yield, with up to 50% of hospitalized patients being discharged with no clear diagnosis. We will outline a structured approach to the syncope patient in the emergency department, highlighting the evidence supporting the role of clinical judgement and the initial electrocardiogram (ECG) in making the preliminary diagnosis and in safely identifying the patients at low risk of short- and long-term adverse events or admitting the patient if likely to benefit from urgent intervention. Clinical decision tools and additional testing may aid in further stratifying patients and may guide disposition. While hospital admission does not seem to offer additional mortality benefit, the efficient utilization of outpatient testing may provide similar diagnostic yield, preventing unnecessary hospitalizations.

Machine Learning and Syncope Management in the ED: The Future Is Coming

In recent years, machine learning (ML) has been promisingly applied in many fields of clinical medicine, both for diagnosis and prognosis prediction. Aims of this narrative review were to summarize the basic concepts of ML applied to clinical medicine and explore its main applications in the emergency department (ED) setting, with a particular focus on syncope management. Through an extensive literature search in PubMed and Embase, we found increasing evidence suggesting that the use of ML algorithms can improve ED triage, diagnosis, and risk stratification of many diseases. However, the lacks of external validation and reliable diagnostic standards currently limit their implementation in clinical practice. Syncope represents a challenging problem for the emergency physician both because its diagnosis is not supported by specific tests and the available prognostic tools proved to be inefficient. ML algorithms have the potential to overcome these limitations and, in the future, they could support the clinician in managing syncope patients more efficiently. However, at present only few studies have addressed this issue, albeit with encouraging results.