San Francisco Syncope Rule to predict short-term serious outcomes: a systematic review

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.

Syncope in the Emergency Department: A Practical Approach

Syncope is a common condition encountered in the emergency department (ED), accounting for about 0.6-3% of all ED visits. Despite its high frequency, a widely accepted management strategy for patients with syncope in the ED is still missing. Since syncope can be the presenting condition of many diseases, both severe and benign, most research efforts have focused on strategies to obtain a definitive etiologic diagnosis. Nevertheless, in everyday clinical practice, a definitive diagnosis is rarely reached after the first evaluation. It is thus troublesome to aid clinicians' reasoning by simply focusing on differential diagnoses. With the current review, we would like to propose a management strategy that guides clinicians both in the identification of conditions that warrant immediate treatment and in the management of patients for whom a diagnosis is not immediately reached, differentiating those that can be safely discharged from those that should be admitted to the hospital or monitored before a final decision. We propose the mnemonic acronym RED-SOS: Recognize syncope; Exclude life-threatening conditions; Diagnose; Stratify the risk of adverse events; Observe; decide on the Setting of care. Based on this acronym, in the different sections of the review, we discuss all the elements that clinicians should consider when assessing patients with syncope.

Risk stratification tools for patients with syncope in emergency medical services and emergency departments: a scoping review

BACKGROUND

Patients with a syncope constitute a challenge for risk stratification in (prehospital) emergency care. Professionals in EMS and ED need to differentiate the high-risk from the low-risk syncope patient, with limited time and resources. Clinical decision rules (CDRs) are designed to support professionals in risk stratification and clinical decision-making. Current CDRs seem unable to meet the standards to be used in the chain of emergency care. However, the need for a structured approach for syncope patients remains. We aimed to generate a broad overview of the available risk stratification tools and identify key elements, scoring systems and measurement properties of these tools.

METHODS

We performed a scoping review with a literature search in MEDLINE, CINAHL, Pubmed, Embase, Cochrane and Web of Science from January 2010 to May 2022. Study selection was done by two researchers independently and was supervised by a third researcher. Data extraction was performed through a data extraction form, and data were summarised through descriptive synthesis. A quality assessment of included studies was performed using a generic quality assessment tool for quantitative research and the AMSTAR-2 for systematic reviews.

RESULTS

The literature search identified 5385 unique studies; 38 were included in the review. We discovered 19 risk stratification tools, one of which was established in EMS patient care. One-third of risk stratification tools have been validated. Two main approaches for the application of the tools were identified. Elements of the tools were categorised in history taking, physical examination, electrocardiogram, additional examinations and other variables. Evaluation of measurement properties showed that negative and positive predictive value was used in half of the studies to assess the accuracy of tools.

CONCLUSION

A total of 19 risk stratification tools for syncope patients were identified. They were primarily established in ED patient care; most are not validated properly. Key elements in the risk stratification related to a potential cardiac problem as cause for the syncope. These insights provide directions for the key elements of a risk stratification tool and for a more advanced process to validate risk stratification tools.

A Deceptively Unremarkable Standstill: A Case Report of a Rare Cardiac Electrophysiologic Event

Ventricular standstill is a rare cardiac event associated with a high mortality. It is considered a ventricular fibrillation equivalent. The longer the duration, the poorer the prognosis. It is therefore unusual for an individual to have recurrent episodes of standstill and survive, without morbidity and rapid mortality. Here, we report the unique case of a 67-year-old male, previously diagnosed with heart disease, requiring intervention, who lived with recurrent syncopal episodes for a decade. Though such occurrences have previously been documented, we seek to stress the importance of using clinical tools in assessing what could easily have been passed off as orthostatic in origin.

e Silva L. Prognostic accuracy of syncope clinical prediction rules in older adults in the emergency department

Study objective

The objective of this study is to evaluate the prognostic accuracy of existing rules (San Francisco Syncope Rule [SFSR], Canadian Syncope Risk Score [CSRS], and FAINT score) in older adults.

Methods

This is a cohort study of adults aged ≥60 years presenting to an academic emergency department (ED) with syncope or near syncope. We used original criteria for all rules except for the FAINT score, in which N-terminal pro-brain natriuretic peptide was largely missing from the extracted data. Patients were deemed positive for each rule if classified as non-low risk. The primary outcome was the presence of 30-day serious outcome, as defined by syncope research guidelines. Sensitivity and negative likelihood ratio (NLR) were calculated with 95% confidence intervals (CIs).

Results

A total of 404 ED visits (mean age of patients, 75.5 years) were included. Of these, 44 (10.9%) had a 30-day serious outcome, and 24 (5.9%) had incomplete 30-day follow-up. SFSR was positive for 280 of 380 visits with complete follow-up. Its sensitivity and NLR for predicting 30-day serious outcomes were 86.4% (95% CI, 72.0%-94.3%) and 0.53 (95% CI, 0.25-1.15), respectively. The CSRS was positive for 299 of 380 visits (sensitivity was 88.6% [95% CI, 76.4%-95.7%], and NLR was 0.50 [95% CI, 0.22-1.17]). The modified FAI(N)T score was positive for 318 of 380 visits (sensitivity was 90.9% [95% CI, 77.4%-97.0%], and NLR was 0.53 [95% CI, 0.20-1.38]).

Conclusion

Existing rules are suboptimal to predict 30-day serious outcomes in older adults presenting with syncope or near syncope to the ED.

Prediction of Pacemaker Requirement in Patients With Unexplained Syncope: The DROP Score

BACKGROUND

Implantable loop recorders (ILR) are increasingly utilised in the evaluation of unexplained syncope. However, they are expensive and do not protect against future syncope.

OBJECTIVES

To compare patients requiring permanent pacemaker (PPM) implantation during ILR follow-up with those without abnormalities detected on ILR in order to identify potential predictors of benefit from upfront pacing.

METHODS

We analysed 100 consecutive patients receiving ILR: Group 1 (n=50) underwent PPM insertion due to bradyarrhythmias detected on ILR; Group 2 (n=50) had no arrhythmias detected on ILR over >3 years follow-up. Baseline clinical characteristics, syncope history, electrocardiographic and echocardiographic parameters were assessed to identify predictors of ultimate requirement for pacing.

RESULTS

Group 1 (64% male, median age 70.8 years; IQR 65.5-78.8) were older than Group 2 (58% male, median 60.2 years; IQR 44.0-73.0 p=0.001) and were less likely to have related historical factors such as overheating, posture and exercise (98% vs 70% p<0.001). PR interval was also longer in Group 1 (192±51 vs 169±23 p=0.006) with greater prevalence of distal conduction system disease (30% vs 4.3% p=0.002). Significant univariate predictors for PPM insertion were distal conduction disease (p=0.007), first degree atrioventricular (AV) block (p=0.003), absence of precipitating factors (p=0.004), and age >65 years (p=0.001). Injury sustained, recurrent syncope, history of atrial fibrillation (AF) or heart failure, left atrial (LA) size and left ventricular ejection fraction (LVEF) were not predictive. These significant predictors were incorporated into the DROP score¹ (0-4). Using time-to-event analysis, no patients with a score of 0 progressed to pacing, while higher scores (3-4) strongly predicted pacing requirement (log-rank p<0.001).

CONCLUSION

The DROP score may be helpful in identifying patients likely to benefit from upfront permanent pacemaker (PPM) insertion following unexplained syncope. Larger prospective studies are required to validate this tool.

Syncope Prediction Scores in the Emergency Department

Syncope is a common clinical presentation defined as a transient loss of consciousness (TLOC) due to cerebral hypoperfusion, characterized by a rapid onset, short duration, and spontaneous complete recovery. Different clinical decision rules (CDRs) and risk stratification scores have been developed to predict short- and long-term risks for adverse outcomes after syncope. The central theme of these prediction systems is consistent with the ESC syncope guidelines. Initial assessment according to the ESC guideline is essential until an optimal and well-validated risk score is available. The focus should be accurate risk stratification to allow prevention of adverse outcomes and optimize the use of limited healthcare resources. In this review article, we summarize and critically appraise the evidence regarding the CDRs for patients presenting with syncope.

Can I Send This Syncope Patient Home From the Emergency Department?

BACKGROUND

Syncope is a common presentation to the emergency department (ED). A significant minority of these patients have potentially life-threatening pathology. Reliably identifying that patients require hospital admission for further workup and intervention is imperative.

CLINICAL QUESTION

In patients who present with syncope, is there a reliable decision tool that clinicians can use to predict the risk of adverse outcome and determine who may be appropriate for discharge?

EVIDENCE REVIEW

Four articles were reviewed. The first retrospective study found no difference in mortality or adverse events in patients admitted for further evaluation rather than discharged home with primary care follow-up. The next two articles examined the derivation and validation of the Canadian Syncope Risk Score (CSRS). After validation with an admission threshold score of -1, the sensitivity and specificity of the CSRS was 97.8% (95% confidence interval [CI] 93.8-99.6%) and 44.3% (95% CI 42.7-45.9%), respectively. The last article looked at the derivation of the FAINT score, a recently developed score to risk stratify syncope patients. A FAINT score of ≥ 1 (any score 1 or higher should be admitted) had a sensitivity of 96.7% (95% CI 92.9-98.8%) and specificity 22.2% (95% CI 20.7-23.8%).

CONCLUSIONS

Syncope remains a difficult chief symptom to disposition from the ED. The CSRS is modestly effective at establishing a low probability of actionable disease or need for intervention. However, CSRS might not reduce unnecessary hospitalizations. The FAINT score has yet to undergo validation; however, the initial derivation study offers less diagnostic accuracy compared with the CSRS.

Multicentre external validation of the Canadian Syncope Risk Score to predict adverse events and comparison with clinical judgement

BACKGROUND

The Canadian Syncope Risk Score (CSRS) has been proposed for syncope risk stratification in the emergency department (ED). The aim of this study is to perform an external multicenter validation of the CSRS and to compare it with clinical judgement.

METHODS

Using patients previously included in the SyMoNE database, we enrolled subjects older than 18 years who presented reporting syncope at the ED. For each patient, we estimated the CSRS and recorded the physician judgement on the patients' risk of adverse events. We performed a 30-day follow-up.

RESULTS

From 1 September 2015 to 28 February 2017, we enrolled 345 patients; the median age was 71 years (IQR 51-81), 174 (50%) were men and 29% were hospitalised. Serious adverse events occurred in 43 (12%) of the patients within 30 days. The area under the curve of the CSRS and clinical judgement was 0.75 (95% CI 0.68 to 0.81) and 0.68 (95% CI 0.61 to 0.74), respectively. The risk of adverse events of patients at low risk according to the CSRS and clinical judgement was 6.7% and 2%, with a sensitivity of 70% (95% CI 54% to 83%) and 95% (95% CI 84% to 99%), respectively.

CONCLUSION

This study represents the first validation analysis of CSRS outside Canada. The overall predictive accuracy of the CSRS is similar to the clinical judgement. However, patients at low risk according to clinical judgement had a lower incidence of adverse events as compared with patients at low risk according to the CSRS. Further studies showing that the adoption of the CSRS improve patients' outcomes is warranted before its widespread implementation.

Multivariable risk scores for predicting short-term outcomes for emergency department patients with unexplained syncope: A systematic review

OBJECTIVES

Emergency department (ED) patients with unexplained syncope are at risk of experiencing an adverse event within 30 days. Our objective was to systematically review the accuracy of multivariate risk stratification scores for identifying adult syncope patients at high and low risk of an adverse event over the next 30 days.

METHODS

We conducted a systematic review of electronic databases (MEDLINE, Cochrane, Embase, and CINAHL) from database creation until May 2020. We sought studies evaluating prediction scores of adults presenting to an ED with syncope. We included studies that followed patients for up to 30 days to identify adverse events such as death, myocardial infarction, stroke, or cardiac surgery. We only included studies with a blinded comparison between baseline clinical features and adverse events. We calculated likelihood ratios and confidence intervals (CIs).

RESULTS

We screened 13,788 abstracts. We included 17 studies evaluating nine risk stratification scores on 24,234 patient visits, where 7.5% (95% CI = 5.3% to 10%) experienced an adverse event. A Canadian Syncope Risk Score (CSRS) of 4 or more was associated with a high likelihood of an adverse event (LR_score≥4  = 11, 95% CI = 8.9 to 14). A CSRS of 0 or less (LR_score≤0  = 0.10, 95% CI = 0.07 to 0.20) was associated with a low likelihood of an adverse event. Other risk scores were not validated on an independent sample, had low positive likelihood ratios for identifying patients at high risk, or had high negative likelihood ratios for identifying patients at low risk.

CONCLUSION

Many risk stratification scores are not validated or not sufficiently accurate for clinical use. The CSRS is an accurate validated prediction score for ED patients with unexplained syncope. Its impact on clinical decision making, admission rates, cost, or outcomes of care is not known.

Syncope in the Emergency Department: A Guide for Clinicians

Syncope is a common presenting symptom to emergency departments, but its evaluation and initial management can be challenging for ED practitioners and particularly urgent in the presence of high-risk features that increase the likelihood of cardiac etiology. Even after thorough clinical evaluation, syncope may remain unexplained. In such instances, practitioners' clinical judgment and risk assessments are critical to guide further management. In this article, evidence-informed strategies are outlined to approach the diagnosis of syncope and provide an overview of syncope clinical decision rules and shared decision-making. By incorporating risk stratification and shared decision-making into syncope care, practitioners can more confidently engage patients and families in disposition decisions to organize appropriate outpatient and follow-up care, observation, or admission.

[Transient loss of consciousness : Algorithm for the (differential) diagnosis of syncope at emergency department]

Transient loss of consciousness (TLoC) is a common complaint leading to presentation at the emergency department. This comprises a heterogeneous group of disorders including cerebral events, metabolic disturbances, intoxication, psychogenic patterns or any form of syncope. While many causes are benign and self-limited not requiring extensive in-hospital evaluation, others are potentially severe. The optimal evaluation of patients with TLoC/syncope follows a risk-adapted diagnostic algorithm in order to exclude life-threatening conditions and to identify those with high risk for further deterioration like structural heart diseases requiring further diagnostic evaluation. Low-risk patients can be discharged without further extensive diagnostic work up. This article presents an algorithm for structured, evidence-based care of the syncope patient in accordance with the recently launched "2018 ESC guidelines for the diagnosis and management of syncope" in order to ensure that patients requiring hospitalization are managed appropriately and those with benign causes are discharged safely. The English version of this algorithm is available at the end of the article under "Supplementary Material".

Outcomes in syncope research: a systematic review and critical appraisal

Syncope is the common clinical manifestation of different diseases, and this makes it difficult to define what outcomes should be considered in prognostic studies. The aim of this study is to critically analyze the outcomes considered in syncope studies through systematic review and expert consensus. We performed a systematic review of the literature to identify prospective studies enrolling consecutive patients presenting to the Emergency Department with syncope, with data on the characteristics and incidence of short-term outcomes. Then, the strengths and weaknesses of each outcome were discussed by international syncope experts to provide practical advice to improve future selection and assessment. 31 studies met our inclusion criteria. There is a high heterogeneity in both outcome choice and incidence between the included studies. The most commonly considered 7-day outcomes are mortality, dysrhythmias, myocardial infarction, stroke, and rehospitalisation. The most commonly considered 30-day outcomes are mortality, haemorrhage requiring blood transfusion, dysrhythmias, myocardial infarction, pacemaker or implantable defibrillator implantation, stroke, pulmonary embolism, and syncope relapse. We present a critical analysis of the pros and cons of the commonly considered outcomes, and provide possible solutions to improve their choice in ED syncope studies. We also support global initiatives to promote the standardization of patient management and data collection.

Prevalence of Pulmonary Embolism in Patients With Syncope

IMPORTANCE

Sparse data and conflicting evidence exist on the prevalence of pulmonary embolism (PE) in patients with syncope.

OBJECTIVE

To estimate the prevalence of PE among patients presenting to the emergency department (ED) for evaluation of syncope.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, observational study analyzed longitudinal administrative data from 5 databases in 4 different countries (Canada, Denmark, Italy, and the United States). Data from all adult patients (aged ≥18 years) who presented to the ED were screened to identify those with syncope codes at discharge. Data were collected from January 1, 2000, through September 30, 2016.

MAIN OUTCOMES AND MEASURES

The prevalence of PE at ED and hospital discharge, identified using codes from the International Classification of Diseases, was considered the primary outcome. Two sensitivity analyses considering prevalence of PE at 90 days of follow-up and prevalence of venous thromboembolism were performed.

RESULTS

A total of 1 671 944 unselected adults who presented to the ED for syncope were included. The prevalence of PE, according to administrative data, ranged from 0.06% (95% CI, 0.05%-0.06%) to 0.55% (95% CI, 0.50%-0.61%) for all patients and from 0.15% (95% CI, 0.14%-0.16%) to 2.10% (95% CI, 1.84%-2.39%) for hospitalized patients. The prevalence of PE at 90 days of follow-up ranged from 0.14% (95% CI, 0.13%-0.14%) to 0.83% (95% CI, 0.80%-0.86%) for all patients and from 0.35% (95% CI, 0.34%-0.37%) to 2.63% (95% CI, 2.34%-2.95%) for hospitalized patients. Finally, the prevalence of venous thromboembolism at 90 days ranged from 0.30% (95% CI, 0.29%-0.31%) to 1.37% (95% CI, 1.33%-1.41%) for all patients and from 0.75% (95% CI, 0.73%-0.78%) to 3.86% (95% CI, 3.51%-4.24%) for hospitalized patients.

CONCLUSIONS AND RELEVANCE

Pulmonary embolism was rarely identified in patients with syncope. Although PE should be considered in every patient, not all patients should undergo evaluation for PE.

Diagnostic accuracy of ICD-9 code 780.2 for the identification of patients with syncope in the emergency department

PURPOSE

Syncope is a common condition that affects individuals of all ages and is responsible for 1-3% of all emergency department (ED) visits. Prospective studies on syncope are often limited by the exiguous number of subjects enrolled. A possible alternative approach would be to use of hospital discharge diagnoses from administrative databases to identify syncope subjects in epidemiological observational studies. We assessed the accuracy of the International Classification of Diseases, Ninth Revision (ICD-9) code 780.2 "syncope and collapse" to identify patients with syncope.

METHODS

Patients in two teaching hospitals in Milan, Italy with a triage assessment for ED access that was possibly related to syncope were recruited in this study. We considered the index test to be the attribution of the ICD-9 code 780.2 at ED discharge and the reference standard to be the diagnosis of syncope by the ED physician.

RESULTS

The sensitivity, specificity, positive and negative predictive values of the ICD-9 code 780.2 to identify patients with syncope were 0.63 (95% confidence interval [CI] 0.58-0.67), 0.98 (95% CI 0.98-0.99), 0.83 (95% CI 0.79-0.87) and 0.95 (95% CI 0.94-0.95), respectively.

CONCLUSIONS

The moderate sensitivity of ICD-9 code 780.2 should be considered when the code is used to identify patients with syncope through administrative databases.

A Population-Based Study of Syncope in the Young

BACKGROUND

The prevalence, hospitalization patterns, and outcomes of pediatric and adolescent syncope have not been rigorously characterized.

METHODS

Patients < 20 years presenting to an emergency department (ED) with a primary diagnosis of syncope (International Classification of Diseases, 10th revision, code R55) between fiscal year (FY) 2006/2007 and FY 2013/2014 in the province of Alberta, Canada were grouped according to discharge status from the ED, ie, (1) admitted to hospital and (2) discharged without admission. Temporal trends and differences in baseline characteristics, medication use, and outcomes between admitted and discharged patients were examined.

RESULTS

The prevalence of syncope increased from 143/100,000 population in FY 2006/2007 to 166/100,000 population in FY 2013/2014 (P < 0.01). The majority of the 11,488 patients who presented to the ED with syncope were discharged home (n = 11,214 [98%]). Cardiac disease was present in 12.7% and thoracic conditions were present in 8% of the study population. A majority of patients (66.2% admitted and 56.4% discharged; P = 0.018) were taking a prescription drug in the year before presentation. By 30 days, 26.1% of admitted patients had a second ED presentation and 8.1% had a rehospitalization. Among discharged patients, the 30-day repeated ED presentation rate was 11.7% and the hospitalization rate was 1.1%. By 1 year, the rates of repeated ED visits increased to 64.1% and 47.5%, and rehospitalization rates increased to 21.4% and 6.8% among admitted and discharged patients, respectively.

CONCLUSIONS

Our data suggest that pediatric and adolescent syncope is increasing in prevalence and represents a growing public health problem. This population has a high burden of comorbidities that likely contribute to increased health care resource use and polypharmacy.

Syncope workup: Greater yield in select trauma population

BACKGROUND

There is great variation in practice regarding the assessment of trauma patients who present with syncope. The purpose of this study was to determine the yield of screening studies (electrocardiogram, echocardiogram, and carotid duplex) and define characteristics to identify groups that may benefit from these investigations.

METHODS

We conducted a retrospective cohort study of all trauma patients from 2003 to 2015 who received a carotid duplex as part of a syncope evaluation at our urban Level 1 Trauma Center. Demographics, clinical findings as well as interventions undertaken (ie: placement of defibrillators/pacemakers) as a result of the syncope evaluation were collected. Data analysis was performed with STATA 14 and relationships between comorbidities, positive findings and interventions were assessed. Significance was assumed for p < 0.05.

RESULTS

736 trauma patients were included in the study. The most common mechanism of injury was fall (592, 82%). A history of congestive heart failure (CHF) and/or coronary artery disease (CAD) and age ≥ 65 were significantly associated with abnormal ECG and ECHO findings, but not with severe carotid stenosis. Elevated Injury Severity Scale (ISS) was significantly associated with an abnormal ECHO on both univariate and multivariate analysis. An abnormal ECG was predictive of an abnormal ECHO (p = 0.02). Ten patients (1.4%) underwent placement of a defibrillator and/or pacemaker, all of whom reported having CHF. Only 11 patients (1.7%) had severe carotid stenosis (>70%) requiring intervention.

CONCLUSION

The screening studies used in a syncope evaluation have low yield in the general trauma population. Carotid duplex should not be routinely performed. Cardiac evaluation should be tailored to individuals with cardiac comorbidities, older age and elevated ISS. An ECG should be used as initial screening in this patient cohort.

Diagnostic yield of device interrogation in the evaluation of syncope in an elderly population

BACKGROUND

Device interrogation has become a standard part of the syncope evaluation for patients admitted with permanent pacemakers (PPM) or implantable cardiac defibrillators (ICD), although few studies have shown interrogation yields clinically useful data. The purpose of this study is to determine the diagnostic yield of device interrogation as well as other commonly performed tests in the workup of unexplained syncope in patients with previously implanted PPMs or ICDs.

METHODS

We retrospectively reviewed records of 88 patients admitted to our medical center for syncope with previously implanted pacemakers between January 1, 2005 and January 1, 2015 using ICD-9 billing data.

RESULTS

Pacemaker interrogation demonstrated an arrhythmia as the cause for syncope in 4 patients (4%) and evidence of device failure secondary to perforation in 1 patient (1%). The cause of syncope was unknown in 34 patients (39%). Orthostatic hypotension was the most commonly identified cause of syncope (26%), followed by vasovagal syncope (13%), autonomic dysfunction (5%), ventricular arrhythmia (3%), atrial arrhythmia (2%), congestive heart failure (2%), stroke (2%), and other less common causes (8%). History was the most important determinant of syncope (36%), followed by orthostatic vital signs (14%), device interrogations (4%), head CT (2%), and transthoracic echocardiogram (1%).

CONCLUSIONS

Device interrogation is rarely useful for elucidating a cause of syncope without concerning physical exam, telemetry, or EKG findings. Interrogation may occasionally yield paroxysmal arrhythmias responsible for syncopal episode, but these rarely alter clinical outcomes. Interrogation appears to be more useful in patients with syncope after recent device placement.

Comparison of different risk stratification systems in predicting short-term serious outcome of syncope patients

BACKGROUND

Determining etiologic causes and prognosis can significantly improve management of syncope patients. The present study aimed to compare the values of San Francisco, Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL), Boston, and Risk Stratification of Syncope in the Emergency Department (ROSE) score clinical decision rules in predicting the short-term serious outcome of syncope patients.

MATERIALS AND METHODS

The present diagnostic accuracy study with 1-week follow-up was designed to evaluate the predictive values of the four mentioned clinical decision rules. Screening performance characteristics of each model in predicting mortality, myocardial infarction (MI), and cerebrovascular accidents (CVAs) were calculated and compared. To evaluate the value of each aforementioned model in predicting the outcome, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were calculated and receiver-operating curve (ROC) curve analysis was done.

RESULTS

A total of 187 patients (mean age: 64.2 ± 17.2 years) were enrolled in the study. Mortality, MI, and CVA were seen in 19 (10.2%), 12 (6.4%), and 36 (19.2%) patients, respectively. Area under the ROC curve for OESIL, San Francisco, Boston, and ROSE models in prediction the risk of 1-week mortality, MI, and CVA was in the 30-70% range, with no significant difference among models (P > 0.05). The pooled model did not show higher accuracy in prediction of mortality, MI, and CVA compared to others (P > 0.05).

CONCLUSION

This study revealed the weakness of all four evaluated models in predicting short-term serious outcome of syncope patients referred to the emergency department without any significant advantage for one among others.

Clinical Decision Rules for Diagnostic Imaging in the Emergency Department: A Research Agenda

BACKGROUND

Major gaps persist in the development, validation, and implementation of clinical decision rules (CDRs) for diagnostic imaging.

OBJECTIVES

The objective of this working group and article was to generate a consensus-based research agenda for the development and implementation of CDRs for diagnostic imaging in the emergency department (ED).

METHODS

The authors followed consensus methodology, as outlined by the journal Academic Emergency Medicine (AEM), combining literature review, electronic surveys, telephonic communications, and a modified nominal group technique. Final discussions occurred in person at the 2015 AEM consensus conference.

RESULTS

A research agenda was developed, prioritizing the following questions: 1) what are the optimal methods to justify the derivation and validation of diagnostic imaging CDRs, 2) what level of evidence is required before disseminating CDRs for widespread implementation, 3) what defines a successful CDR, 4) how should investigators best compare CDRs to clinical judgment, and 5) what disease states are amenable (and highest priority) to development of CDRs for diagnostic imaging in the ED?

CONCLUSIONS

The concepts discussed herein demonstrate the need for further research on CDR development and implementation regarding diagnostic imaging in the ED. Addressing this research agenda should have direct applicability to patients, clinicians, and health care systems.

Syncope: the emergency department and beyond

Syncope is a common problem encountered by both emergency and internal medicine physicians. This review focuses on not only the assessment, risk stratification and management of the syncope patient, but also the latest thinking on diagnostic testing including more novel tools such as biomarkers and ambulatory patch monitor recording.

Syncope risk stratification tools vs clinical judgment: an individual patient data meta-analysis

BACKGROUND

There have been several attempts to derive syncope prediction tools to guide clinician decision-making. However, they have not been largely adopted, possibly because of their lack of sensitivity and specificity. We sought to externally validate the existing tools and to compare them with clinical judgment, using an individual patient data meta-analysis approach.

METHODS

Electronic databases, bibliographies, and experts in the field were screened to find all prospective studies enrolling consecutive subjects presenting with syncope to the emergency department. Prediction tools and clinical judgment were applied to all patients in each dataset. Serious outcomes and death were considered separately during emergency department stay and at 10 and 30 days after presenting syncope. Pooled sensitivities, specificities, likelihood ratios, and diagnostic odds ratios, with 95% confidence intervals, were calculated.

RESULTS

Thirteen potentially relevant papers were retrieved (11 authors). Six authors agreed to share individual patient data. In total, 3681 patients were included. Three prediction tools (Osservatorio Epidemiologico sulla Sincope del Lazio [OESIL], San Francisco Syncope Rule [SFSR], Evaluation of Guidelines in Syncope Study [EGSYS]) could be assessed by the available datasets. None of the evaluated prediction tools performed better than clinical judgment in identifying serious outcomes during emergency department stay, and at 10 and 30 days after syncope.

CONCLUSIONS

Despite the use of an individual patient data approach to reduce heterogeneity among studies, a large variability was still present. Current prediction tools did not show better sensitivity, specificity, or prognostic yield compared with clinical judgment in predicting short-term serious outcome after syncope. Our systematic review strengthens the evidence that current prediction tools should not be strictly used in clinical practice.

Syncope

Syncope is common representing approximately 3% of ED visits and up to 6% of hospital admissions, with a cost close to 2 billion dollars per year. Diagnostic testing is often poorly sensitive and evaluations commonly lack a standardized approach. A mindful and systematic approach can increase sensitivity and improve diagnostic accuracy. A thorough history and physical exam is paramount, as conclusions drawn from the history and exam will guide further assessment. Developing a strategy for the first and, if necessary, subsequent tests will improve the accuracy of identifying the etiology of syncope and reduce cost. Although syncope has a favorable prognosis, identification of patients with structural heart disease is critical, as these patients are at greatest risk for mortality. Several risk scoring systems have been developed to help separate high risk from low risk patients.

Syncope risk stratification in the ED

Syncope may be the final common presentation of a number of clinical conditions spanning benign (i.e. neurally-mediated syncope) to life-threatening diseases (i.e. cardiac syncope). Hospitalization rate after a syncopal episode is high. An effective risk stratification is crucial to identify patients at risk of poor prognosis in the short term period to avoid unnecessary hospital admissions. The decision to admit or discharge a syncope patient from the ED is often based on the physician's clinical judgment. In recent years, several prognostic tools (i.e. clinical prediction rules and risk scores) have been developed to provide emergency physicians with accurate guidelines for hospital admission. At present, there are no compelling evidence that prognostic tools perform better than physician's clinical judgment in assessing the short-term outcome of syncope. However, the risk factors characterizing clinical prediction rules and risk scores may be profitably used by emergency doctors in their decision making, specifically whenever a syncope patient has to be discharged from ED or admitted to hospital. Patients with syncope of undetermined etiology, who are characterized by an intermediate-high risk profile after the initial evaluation, should be monitored in the ED. Indeed, data suggest that the 48h following syncope are at the highest risk for major adverse events. A new tool for syncope management is represented by the Syncope Unit in the ED or in an outpatient setting. Syncope Unit may reduce hospitalization and length of hospital stay. However, further studies are needed to clarify whether syncope patients' prognosis can be also improved.

Association of corrected QT interval with long-term mortality in patients with syncope

INTRODUCTION

The electrocardiographic parameters QRS duration, QRS-T angle and QTc can predict mortality in patients with cardiovascular disease. The prgnostic value of these parameters in hospitalized patients with syncope needs investigation.

MATERIAL AND METHODS

We retrospectively studied 590 consecutive patients hospitalized with syncope. After excluding patients with baseline abnormal rhythm, QT- prolonging medications, and missing data, 459 patients were analyzed. Baseline demographic characteristics, co-morbidities, medication use, San Francisco Syncope Rule (SFSR) and Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) score and data on mortality were collected. The categorical variables and continuous variables of the 2 groups of patients with prolonged QTc and normal QTc interval were analyzed by Fischer's exact test and Mann-Whitney Test. A stepwise Cox regression model was used for time to death analysis.

RESULTS

Of 459 patients, prolonged QTc interval was observed in 122 (27%). Mean follow-up was 41 months. Patients with prolonged QTc interval had higher prevalence of cardiovascular disease, OESIL score, high risk SFSR, hypertension, dyslipidemia, coronary artery disease, congestive heart failure, and increased mortality. Stepwise Cox regression analysis showed that significant independent prognostic factors for time to death were prolonged QTc interval (p = 0.005), age (p = 0.001), diabetes mellitus (p = 0.001) and history of malignancy (p = 0.006). QRS duration and QRS-T angle were not independent predictors of mortality.

CONCLUSIONS

A prolonged QTc interval is an independent predictor of long-term mortality in hospitalized patients with syncope.

Identifying cardiac syncope based on clinical history: a literature-based model tested in four independent datasets

BACKGROUND

We aimed to develop and test a literature-based model for symptoms that associate with cardiac causes of syncope.

METHODS AND RESULTS

Seven studies (the derivation sample) reporting ≥2 predictors of cardiac syncope were identified (4 Italian, 1 Swiss, 1 Canadian, and 1 from the United States). From these, 10 criteria were identified as diagnostic predictors. The conditional probability of each predictor was calculated by summation of the reported frequencies. A model of conditional probabilities and a priori probabilities of cardiac syncope was constructed. The model was tested in four datasets of patients with syncope (the test sample) from Calgary (n=670; 21% had cardiac syncope), Amsterdam (n=503; 9%), Milan (n=689; 5%) and Rochester (3877; 11%). In the derivation sample ten variables were significantly associated with cardiac syncope: age, gender, structural heart disease, low number of spells, brief or absent prodrome, supine syncope, effort syncope, and absence of nausea, diaphoresis and blurred vision. Fitting the test datasets to the full model gave C-statistics of 0.87 (Calgary), 0.84 (Amsterdam), 0.72 (Milan) and 0.71 (Rochester). Model sensitivity and specificity were 92% and 68% for Calgary, 86% and 67% for Amsterdam, 76% and 59% for Milan, and 73% and 52% for Rochester. A model with 5 variables (age, gender, structural heart disease, low number of spells, and lack of prodromal symptoms) was as accurate as the total set.

CONCLUSION

A simple literature-based Bayesian model of historical criteria can distinguish patients with cardiac syncope from other patients with syncope with moderate accuracy.

Syncope risk stratification in the emergency department

The overall risk for a patient entering the emergency department (ED) because of syncope ranges between 5% and 15%, and the mortality at 1 week is approximately 1%. The primary goal for the ED physician is thus to discriminate individuals at low risk, who can be safely discharged, from patients at high risk, who warrant a prompt hospitalization for monitoring and/or appropriate treatment. Different rules and risk scores have been proposed. More ad hoc studies are needed to define the prognostic and diagnostic roles of the brain natriuretic peptide and other noninvasive laboratory markers.

Recognizing life-threatening causes of syncope

While the overall prognosis of syncope is favorable, the identification of individuals with a potentially life-threatening cause is of paramount importance. Cardiac syncope is associated with an elevated risk of mortality, and includes both primary arrhythmic and obstructive etiologies. Identification of these individuals is contingent on careful clinical assessment and judicious use of diagnostic investigations. This article focuses on life-threatening causes of syncope and a diagnostic approach to facilitate their identification.

Validation of the San Francisco Syncope Rule in two hospital emergency departments in an Asian population

OBJECTIVES

The objective was to externally validate the ability of the San Francisco Syncope Rule (SFSR) to accurately identify patients who will experience a 7-day serious clinical event in an Asian population.

METHODS

This was a prospective cohort study, with a sample of adult patients with syncope and near-syncope enrolled. Patients 12 years old and below and patients with loss of consciousness after head trauma, a witnessed seizure, with known alcohol or illicit drug ingestion, and altered level of consciousness or persistent new neurologic deficits were excluded. The patients were evaluated for the presence of one or more of the five SFSR variables: shortness of breath, history of heart failure, hematocrit <30%, systolic blood pressure <90 mm Hg, and abnormal electrocardiogram (ECG). The patients were followed up by medical record review or telephone interview. Seven-day outcomes were death, arrhythmia, myocardial infarction, acute pulmonary edema, significant structural heart disease, pulmonary embolism, major cardiac procedure, stroke, subarachnoid hemorrhage, major bleeding, and anemia.

RESULTS

A total of 1,250 patients from two centers were recruited. Fifty-six patients were excluded from primary analysis because of incomplete data (n = 55) and/or they were noncontactable for follow-up (n = 32). Of the 1,194 patients analyzed, 138 patients (11.6%) experienced adverse outcomes at 7 days. The rule performed with a sensitivity of 94.2% (95% confidence interval [CI] = 89.0% to 97.0%) and a specificity of 50.8% (95% CI = 47.7% to 53.8%).

CONCLUSIONS

In this study, SFSR rule had a sensitivity of 94.2%. This suggests caution on the strict application of the rule to all patients presenting with syncope. It should only be used as an aide in clinical decision-making in this population.

[Syncope--algorithms for emergency medicine]

Syncope is a common symptom in the emergency department. While most causes are benign and self-limiting not requiring extensive in-hospital evaluation, others are potentially severe. The optimal evaluation of patients with syncope follows a risk-adapted diagnostic algorithm in order to exclude life-threatening conditions and to identify those with high risk for further deterioration, such as structural heart diseases requiring further diagnostic evaluation. Low risk patients can be discharged without further extensive diagnostic work-up. This article presents an algorithm for the diagnostics of syncope in accordance with current guidelines.