International Validation of the Canadian Syncope Risk Score : A Cohort Study.

BACKGROUND: The Canadian Syncope Risk Score (CSRS) was developed to predict 30-day serious outcomes not evident during emergency department (ED) evaluation. OBJECTIVE: To externally validate the CSRS and compare it with another validated score, the Osservatorio Epidemiologico della Sincope nel Lazio (OESIL) score. DESIGN: Prospective cohort study. SETTING: Large, international, multicenter study recruiting patients in EDs in 8 countries on 3 continents. PARTICIPANTS: Patients with syncope aged 40 years or older presenting to the ED within 12 hours of syncope. MEASUREMENTS: Composite outcome of serious clinical plus procedural events (primary outcome) and the primary composite outcome excluding procedural interventions (secondary outcome). RESULTS: Among 2283 patients with a mean age of 68 years, the primary composite outcome occurred in 7.2%, and the composite outcome excluding procedural interventions occurred in 3.1% at 30 days. Prognostic performance of the CSRS was good for both 30-day composite outcomes and better compared with the OESIL score (area under the receiver-operating characteristic curve [AUC], 0.85 [95% CI, 0.83 to 0.88] vs. 0.74 [CI, 0.71 to 0.78] and 0.80 [CI, 0.75 to 0.84] vs. 0.69 [CI, 0.64 to 0.75], respectively). Safety of triage, as measured by the frequency of the primary composite outcome in the low-risk group, was higher using the CSRS (19 of 1388 [0.6%]) versus the OESIL score (17 of 1104 [1.5%]). A simplified model including only the clinician classification of syncope (cardiac syncope, vasovagal syncope, or other) variable at ED discharge-a component of the CSRS-achieved similar discrimination as the CSRS (AUC, 0.83 [CI, 0.80 to 0.87] for the primary composite outcome). LIMITATION: Unable to disentangle the influence of other CSRS components on clinician classification of syncope at ED discharge. CONCLUSION: This international external validation of the CSRS showed good performance in identifying patients at low risk for serious outcomes outside of Canada and superior performance compared with the OESIL score. However, clinician classification of syncope at ED discharge seems to explain much of the performance of the CSRS in this study. The clinical utility of the CSRS remains uncertain. PRIMARY FUNDING SOURCE: Swiss National Science Foundation & Swiss Heart Foundation.

Development of a Novel Emergency Department Quality Measure to Reduce Very Low-Risk Syncope Hospitalizations.

STUDY OBJECTIVE: Emergency department (ED) evaluations for syncope are common, representing 1.3 million annual US visits and $2 billion in related hospitalizations. Despite evidence supporting risk stratification and outpatient management, variation in syncope hospitalization rates persist. We sought to develop a new quality measure for very low-risk adult ED patients with syncope that could be applied to administrative data. METHODS: We developed this quality measure in 2 phases. First, we used an existing prospective, observational ED patient data set to identify a very low-risk cohort with unexplained syncope using 2 variables: age less than 50 years and no history of heart disease. We then applied this to the 2019 Nationwide Emergency Department Sample (NEDS) to assess its potential effect, assessing for hospital-level factors associated with hospitalization variation. RESULTS: Of the 8,647 adult patients in the prospective cohort, 3,292 (38%) patients fulfilled these 2 criteria: age less than 50 years and no history of heart disease. Of these, 15 (0.46%) suffered serious adverse events within 30 days. In the NEDS, there were an estimated 566,031 patients meeting these 2 criteria, of whom 15,507 (2.7%; 95% confidence interval [CI] 2.48% to 3.00%) were hospitalized. We found substantial variation in the hospitalization rates for this very low-risk cohort, with a median rate of 1.7% (range 0% to 100%; interquartile range 0% to 3.9%). Factors associated with increased hospitalization rates included a yearly ED volume of more than 80,000 (odds ratio [OR] 3.14; 95% CI 2.02 to 4.89) and metropolitan teaching status (OR 1.5; 95% CI 1.24 to 1.81). CONCLUSION: In summary, our novel syncope quality measure can assess variation in low-value hospitalizations for unexplained syncope. The application of this measure could improve the value of syncope care.

Personalised risk prediction following emergency department assessment for syncope.

BACKGROUND: Published risk tools do not provide possible management options for syncope in the emergency department (ED). Using the 30-day observed risk estimates based on the Canadian Syncope Risk Score (CSRS), we developed personalised risk prediction to guide management decisions. METHODS: We pooled previously reported data from two large cohort studies, the CSRS derivation and validation cohorts, that prospectively enrolled adults (≥16 years) with syncope at 11 Canadian EDs between 2010 and 2018. Using this larger cohort, we calculated the CSRS calibration and discrimination, and determined with greater precision than in previous studies the 30-day risk of adjudicated serious outcomes not identified during the index ED evaluation depending on the CSRS and the risk category. Based on these findings, we developed an on-line calculator and pictorial decision aids. RESULTS: 8233 patients were included of whom 295 (3.6%, 95% CI 3.2% to 4.0%) experienced 30-day serious outcomes. The calibration slope was 1.0, and the area under the curve was 0.88 (95% CI 0.87 to 0.91). The observed risk increased from 0.3% (95% CI 0.2% to 0.5%) in the very-low-risk group (CSRS -3 to -2) to 42.7% (95% CI 35.0% to 50.7%), in the very-high-risk (CSRS≥+6) group (Cochrane-Armitage trend test p<0.001). Among the very-low and low-risk patients (score -3 to 0), ≤1.0% had any serious outcome, there was one death due to sepsis and none suffered a ventricular arrhythmia. Among the medium-risk patients (score +1 to+3), 7.8% had serious outcomes, with <1% death, and a serious outcome was present in >20% of high/very-high-risk patients (score +4 to+11) including 4%-6% deaths. The online calculator and the pictorial aids can be found at: https://teamvenk.com/csrs CONCLUSIONS: 30-day observed risk estimates from a large cohort of patients can be obtained for management decision-making. Our work suggests very-low-risk and low-risk patients may be discharged, discussion with patients regarding investigations and disposition are needed for medium-risk patients, and high-risk patients should be hospitalised. The online calculator, accompanied by pictorial decision aids for the CSRS, may assist in discussion with patients.

Electrical versus pharmacological cardioversion for emergency department patients with acute atrial fibrillation (RAFF2): a partial factorial randomised trial.

BACKGROUND: Acute atrial fibrillation is the most common arrythmia treated in the emergency department. Our primary aim was to compare conversion to sinus rhythm between pharmacological cardioversion followed by electrical cardioversion (drug-shock), and electrical cardioversion alone (shock-only). Our secondary aim was to compare the effectiveness of two pad positions for electrical cardioversion. METHODS: We did a partial factorial trial of two protocols for patients with acute atrial fibrillation at 11 academic hospital emergency departments in Canada. We enrolled adult patients with acute atrial fibrillation. Protocol 1 was a randomised, blinded, placebo-controlled comparison of attempted pharmacological cardioversion with intravenous procainamide (15 mg/kg over 30 min) followed by electrical cardioversion if necessary (up to three shocks, each of ≥200 J), and placebo infusion followed by electrical cardioversion. For patients having electrical cardioversion, we used Protocol 2, a randomised, open-label, nested comparison of anteroposterior versus anterolateral pad positions. Patients were randomly assigned (1:1, stratified by study site) for Protocol 1 by on-site research personnel using an online electronic data capture system. Randomisation for Protocol 2 occurred 30 min after drug infusion for patients who had not converted and was stratified by site and Protocol 1 allocation. Patients and all research and emergency department staff were masked to treatment allocation for Protocol 1. The primary outcome was conversion to normal sinus rhythm for at least 30 min at any time after randomisation and up to a point immediately after three shocks. Protocol 1 was analysed by intention to treat and Protocol 2 excluded patients who did not receive electrical cardioversion. This study is registered at ClinicalTrials.gov, number NCT01891058. FINDINGS: Between July 18, 2013, and Oct 17, 2018, we enrolled 396 patients, and none were lost to follow-up. In the drug-shock group (n=204), conversion to sinus rhythm occurred in 196 (96%) patients and in the shock-only group (n=192), conversion occurred in 176 (92%) patients (absolute difference 4%; 95% CI 0-9; p=0·07). The proportion of patients discharged home was 97% (n=198) versus 95% (n=183; p=0·60). 106 (52%) patients in the drug-shock group converted after drug infusion only. No patients had serious adverse events in follow-up. The different pad positions in Protocol 2 (n=244), had similar conversions to sinus rhythm (119 [94%] of 127 in anterolateral group vs 108 [92%] of 117 in anteroposterior group; p=0·68). INTERPRETATION: Both the drug-shock and shock-only strategies were highly effective, rapid, and safe in restoring sinus rhythm for patients in the emergency department with acute atrial fibrillation, avoiding the need for return to hospital. The drug infusion worked for about half of patients and avoided the resource intensive procedural sedation required for electrical cardioversion. We also found no significant difference between the anterolateral and anteroposterior pad positions for electrical cardioversion. Immediate rhythm control for patients in the emergency department with acute atrial fibrillation leads to excellent outcomes. FUNDING: Heart and Stroke Foundation of Canada and the Canadian Institutes of Health Research.

Adverse Events Among Emergency Department Patients With Cardiovascular Conditions: A Multicenter Study.

STUDY OBJECTIVE: We aim to determine incidence and type of adverse events (adverse outcomes related to emergency care) among emergency department (ED) patients discharged with recent-onset atrial fibrillation, acute heart failure, and syncope. METHODS: This 5-year prospective cohort study included high-acuity adult patients discharged with the 3 sentinel diagnoses from 6 tertiary care Canadian EDs. We screened all ED visits for eligibility and performed telephone interviews 14 days postdischarge to identify flagged outcomes: death, hospital admission, return ED visit, health care provider visit, and new or worsening symptoms. We created case summaries describing index ED visit and flagged outcomes, and trained emergency physicians reviewed case summaries to identify adverse events. We reported adverse event incidence and rates with 95% confidence intervals and contributing factor themes. RESULTS: Among 4,741 subjects (mean age 70.2 years; 51.2% men), we observed 170 adverse events (3.6 per 100 patients; 95% confidence interval 3.1 to 4.2). Patients discharged with acute heart failure were most likely to experience adverse events (5.3%), followed by those with atrial fibrillation (2.0%) and syncope (0.8%). We noted variation in absolute adverse event rates across sites from 0.7 to 6.0 per 100 patients. The most common adverse event types were management issues, diagnostic issues, and unsafe disposition decisions. Frequent contributing factor themes included failure to recognize underlying causes and inappropriate management of dual diagnoses. CONCLUSION: Among adverse events after ED discharge for patients with these 3 sentinel cardiovascular diagnoses, we identified quality improvement opportunities such as strengthening dual diagnosis detection and evidence-based clinical practice guideline adherence.

The Safety and Effectiveness of On-Site Paramedic and Allied Health Treatment Interventions Targeting the Reduction of Emergency Department Visits by Long-Term Care Patients: Systematic Review.

INTRODUCTION: Programs that seek to avoid emergency department (ED) visits from patients residing in long-term care facilities are increasing. We sought to identify existing programs where allied healthcare personnel are the primary providers of the intervention and, to evaluate their effectiveness and safety. METHODS: We systematically searched Medline, CINAHL and EMBASE with terms relating to long-term care, emergency services, hospitalization and allied health personnel. We reviewed 11,176 abstracts and included 22 studies in our narrative synthesis, which we grouped by intervention category. RESULTS: We found five categories of interventions including: 1) use of advanced practice nursing; 2) a program called Interventions to Reduce Acute Care Transfers (INTERACT); 3) end-of-life care; 4) condition specific interventions; and 5) use of extended care paramedics. Among studies measuring that outcome, 13/13 reported a decrease in ED visits, and 16/17 reported a decrease hospitalization in the intervention groups. Patient adverse events such as functional status and relapse were seldom reported (6/22) as were measures of emergency system function such as crowding/inability of paramedics to transfer care to the ED (1/22). Only 4/22 studies evaluated patient mortality and 3/4 found a non-statistically significant worsening. CONCLUSION: We found five types of programs/interventions which all demonstrated a decrease in ED visits or hospitalization. However, most studies were observational and few assessed patient safety. Many identified programs focused on increased primary care for patients, and interventions addressing acute care issues, such as community paramedics, deserve more study.

Does N-Terminal Pro-B-Type Natriuretic Peptide Improve the Risk Stratification of Emergency Department Patients With Syncope?

BACKGROUND: Studies have reported that natriuretic peptides provide prognostic information for emergency department (ED) syncope. OBJECTIVE: To evaluate whether adding N-terminal pro-B-type natriuretic peptide (NT-proBNP) to the Canadian Syncope Risk Score (CSRS) improves prediction of 30-day serious adverse events (SAEs). DESIGN: Prospective cohort study. SETTING: 6 EDs in 2 Canadian provinces. PARTICIPANTS: 1452 adult ED patients with syncope. INTERVENTION: Serum NT-proBNP was measured locally at 1 site and batch processed at a central laboratory from other sites. The concentrations were not available to treating physicians or for adjudication of outcomes. MEASUREMENTS: An adjudicated composite outcome of 30-day SAEs, including death and cardiac (arrhythmic and nonarrhythmic) and noncardiac events. RESULTS: Of 1452 patients enrolled, 152 (10.5% [95% CI, 9.0% to 12.1%]) had 30-day SAEs, 57 (3.9%) of which were identified after the index ED disposition. Serum NT-proBNP concentrations were significantly higher among patients with SAEs than those without them (median, 626.5 ng/L vs. 81 ng/L; P < 0.001). Adding NT-proBNP values to the CSRS did not significantly improve prognostication (c-statistic, 0.89 and 0.90; P = 0.12 for difference), regardless of SAE subgroup or whether the SAE was identified after the index ED visit. The net reclassification index shows that NT-proBNP would have correctly reclassified 3% of patients with SAEs at the expense of incorrectly reclassifying 2% of patients without SAEs. LIMITATIONS: Our study was powered to detect a 3% difference in the area under the curve. The heterogeneity of outcomes and robust baseline discrimination by the CSRS will make improvements challenging. CONCLUSION: Although serum NT-proBNP concentrations were generally much higher among ED patients with syncope who had a 30-day SAE, this blood test added little new information to the CSRS. Routine use of NT-proBNP for ED syncope prognostication is not recommended. PRIMARY FUNDING SOURCE: Physicians' Services Incorporated Foundation, Canadian Institutes of Health Research, and The Ottawa Hospital Academic Medical Organization.

Multi-centre implementation of an Educational program to improve the Cardiac Arrest diagnostic accuracy of ambulance Telecommunicators and survival outcomes for sudden cardiac arrest victims: the EduCATe study design and methodology.

BACKGROUND: Sudden cardiac death remains a leading cause of mortality in Canada, resulting in more than 35,000 deaths annually. Most cardiac arrest victims collapse in their own home (85% of the time) and 50% are witnessed by a family member or bystander. Survivors have a quality of life similar to the general population, but the overall survival rate for out-of-hospital cardiac arrest (OHCA) rarely exceeds 8%. Victims are almost four times more likely to survive when receiving bystander CPR, but bystander CPR rates have remained low in Canada over the past decade, not exceeding 15-25% until recently. Telecommunication-assisted CPR instructions have been shown to significantly increase bystander CPR rates, but agonal breathing may be misinterpreted as a sign of life by 9-1-1 callers and telecommunicators, and is responsible for as much as 50% of missed OHCA diagnoses. We sought to improve the ability and speed with which ambulance telecommunicators can recognize OHCA over the phone, initiate timely CPR instructions, and improve survival. METHODS: In this multi-center national study, we will implement and evaluate an educational program developed for ambulance telecommunicators using a multiple baseline interrupted time-series design. We will compare outcomes 12 months before and after the implementation of a 20-min theory-based educational video addressing barriers to recognition of OHCA while in the presence of agonal breathing. Participating Canadian sites demonstrated prior ability to collect standardized data on OHCA. Data will be collected from eligible 9-1-1 recordings, paramedic documentation and hospital medical records. Eligible cases will include suspected or confirmed OHCA of presumed cardiac origin in patients of any age with attempted resuscitation. DISCUSSION: The ability of telecommunication-assisted CPR instructions to improve bystander CPR and survival rates for OHCA victims is undeniable. The ability of telecommunicators to recognize OHCA over the phone is unequivocally impeded by relative lack of training on agonal breathing, and reluctance to initiate CPR instructions when in doubt. Our pilot data suggests the potential impact of this project will be to increase absolute OHCA recognition and bystander CPR rates by at least 10%, and absolute out-of-hospital cardiac arrest survival by 5% or more. TRIAL REGISTRATION: Prospectively registered on March 28, 2019 at ClinicalTrials.gov identifier: NCT03894059 .

Syncope Time Frames for Adverse Events after Emergency Department Presentation: An Individual Patient Data Meta-Analysis.

Background and Objectives: Knowledge of the incidence and time frames of the adverse events of patients presenting syncope at the ED is essential for developing effective management strategies. The aim of the present study was to perform a meta-analysis of the incidence and time frames of adverse events of syncope patients. Materials and Methods: We combined individual patients' data from prospective observational studies including adult patients who presented syncope at the ED. We assessed the pooled rate of adverse events at 24 h, 72 h, 7-10 days, 1 month and 1 year after ED evaluation. Results: We included nine studies that enrolled 12,269 patients. The mean age varied between 53 and 73 years, with 42% to 57% females. The pooled rate of adverse events was 5.1% (95% CI 3.4% to 7.7%) at 24 h, 7.0% (95% CI 4.9% to 9.9%) at 72 h, 8.4% (95% CI 6.2% to 11.3%) at 7-10 days, 10.3% (95% CI 7.8% to 13.3%) at 1 month and 21.3% (95% CI 15.8% to 28.0%) at 1 year. The pooled death rate was 0.2% (95% CI 0.1% to 0.5%) at 24 h, 0.3% (95% CI 0.1% to 0.7%) at 72 h, 0.5% (95% CI 0.3% to 0.9%) at 7-10 days, 1% (95% CI 0.6% to 1.7%) at 1 month and 5.9% (95% CI 4.5% to 7.7%) at 1 year. The most common adverse event was arrhythmia, for which its rate was 3.1% (95% CI 2.0% to 4.9%) at 24 h, 4.8% (95% CI 3.5% to 6.7%) at 72 h, 5.8% (95% CI 4.2% to 7.9%) at 7-10 days, 6.9% (95% CI 5.3% to 9.1%) at 1 month and 9.9% (95% CI 5.5% to 17) at 1 year. Ventricular arrhythmia was rare. Conclusions: The risk of death or life-threatening adverse event is rare in patients presenting syncope at the ED. The most common adverse events are brady and supraventricular arrhythmias, which occur during the first 3 days. Prolonged ECG monitoring in the ED in a short stay unit with ECG monitoring facilities may, therefore, be beneficial.

Duration of Electrocardiographic Monitoring of Emergency Department Patients With Syncope.

BACKGROUND: The optimal duration of cardiac rhythm monitoring after emergency department (ED) presentation for syncope is poorly described. We sought to describe the incidence and time to arrhythmia occurrence to inform decisions regarding duration of monitoring based on ED risk stratification. METHODS: We conducted a prospective cohort study with enrolled adult patients (≥16 years old) presenting within 24 hours of syncope at 6 EDs. We collected baseline characteristics, time of syncope and ED arrival, and the Canadian Syncope Risk Score (CSRS) risk category. We followed subjects for 30 days, and our adjudicated primary outcome was serious arrhythmic conditions (arrhythmias, interventions for arrhythmias, and unexplained death). After excluding patients with an obvious serious condition on ED presentation and those with missing CSRS predictors, we used Kaplan-Meier analysis to describe the time to serious arrhythmic outcomes. RESULTS: A total of 5581 patients (mean age, 53.4 years; 54.5% females; 11.6% hospitalized) were available for analysis, including 346 (6.2%) for whom the 30-day follow-up was incomplete and who were censored at the last follow-up time. A total of 417 patients (7.5%) experienced serious outcomes, 207 of which (3.7%; 95% CI, 3.3%-4.2%) were arrhythmic (161 arrhythmias, 30 cardiac device implantations, 16 unexplained deaths). Overall, 4123 (73.9%) were classified as CSRS low risk, 1062 (19.0%) medium risk, and 396 (7.1%) high risk. The CSRS accurately stratified subjects as low risk (0.4% risk for 30-day arrhythmic outcome), medium risk (8.7% risk), and high risk (25.3% risk). One-half of arrhythmic outcomes were identified within 2 hours of ED arrival in low-risk patients and within 6 hours in medium- and high-risk patients, and the residual risk after these cut points were 0.2% for low-risk, 5.0% for medium-risk, and 18.1% for high-risk patients. Overall, 91.7% of arrhythmic outcomes among medium- and high-risk patients, including all ventricular arrhythmias, were identified within 15 days. None of the low-risk patients experienced ventricular arrhythmia or unexplained death, whereas 0.9% of medium-risk patients and 6.3% of high-risk patients experienced them ( P<0.0001). CONCLUSIONS: Serious underlying arrhythmia was often identified within the first 2 hours of ED arrival for CSRS low-risk patients and within 6 hours for CSRS medium- and high-risk patients. Outpatient cardiac rhythm monitoring for 15 days for selected medium-risk patients and all high-risk patients discharged from the hospital should also be considered.

Benefit of hospital admission for detecting serious adverse events among emergency department patients with syncope: a propensity-score-matched analysis of a multicentre prospective cohort.

BACKGROUND: The benefit of hospital admission after emergency department evaluation for syncope is unclear. We sought to determine the association between hospital admission and detection of serious adverse events, and whether this varied according to the Canadian Syncope Risk Score (CSRS). METHODS: We conducted a secondary analysis of a multicentre prospective cohort of patients assessed in the emergency department for syncope. We compared patients admitted to hospital and discharged patients, using propensity scores to match 1:1 for risk of a serious adverse event. The primary outcome was detection of a serious adverse event in hospital for admitted patients or within 30 days after emergency department disposition for discharged patients. RESULTS: We included 8183 patients, of whom 743 (9.1%) were admitted; 658/743 (88.6%) were matched. Admitted patients had higher odds of detection of a serious adverse event (odds ratio [OR] 5.0, 95% confidence interval [CI] 3.3-7.4), nonfatal arrhythmia (OR 5.1, 95% CI 2.9-8.8) and nonarrhythmic serious adverse event (OR 6.3, 95% CI 2.9-13.5). There were no significant differences between the 2 groups in death (OR 1.0, 95% CI 0.4-2.7) or detection of ventricular arrhythmia (OR 2.0, 95% CI 0.7-6.0). Differences between admitted and discharged patients in detection of serious adverse events were greater for those with a CSRS indicating medium to high risk (p = 0.04). INTERPRETATION: Patients with syncope were more likely to have serious adverse events identified within 30 days if they were admitted to hospital rather than discharged from the emergency department. However, the benefit of hospital admission is low for patients at low risk of a serious adverse event.

Evaluation of the Ottawa 3DY as a screening tool for cognitive impairment in older emergency department patients.

OBJECTIVE: This study sought to evaluate the implementation of the Ottawa 3DY Tool, a simple screening instrument for cognitive impairment, by front-line ED clinicians. METHODS: We conducted a prospective cohort study in an academic ED. Patients ≥75 years underwent cognitive screening with the Ottawa 3DY by front-line nurses and physicians. Descriptive statistics were used to describe level of implementation and acceptability of the tool. Sensitivity and specificity was calculated using an Mini-Mental State Exam <25 as the cut-off for cognitive impairment. A weighted kappa was calculated to establish inter-rater agreement. RESULTS: Cognitive screening was completed in 260/332 eligible patients (78.3%), who were 60% female and had a mean age of 83.7 years. Facilitators to screening: perceived importance and ownership of screening and feasibility of Ottawa 3DY. Barriers to screening were: over confidence in clinical judgement and perceived lack of patient benefit. Ottawa 3DY had a sensitivity of 84.6% (64.3-95.0) and specificity of 54.2% (39.3-68.4) when completed by nurses. When completed by emergency physicians, sensitivity was 78.9% (53.9-93.0) and specificity was 70.0% (45.7-87.2). Inter-rater agreement kappa score was 0.67. DISCUSSION: This study demonstrated that incorporating the Ottawa 3DY tool into the routine evaluation of older ED patients by front-line ED clinicians is both feasible and effective. With its demonstrated good inter-rater reliability and moderate level of sensitivity and specificity when compared with the much longer MMSE, the routine adoption of this tool may help lead to improved recognition of cognitive impairment and ultimately patient and system outcomes.

Prevalence of Pulmonary Embolism Among Emergency Department Patients With Syncope: A Multicenter Prospective Cohort Study.

STUDY OBJECTIVE: The prevalence of pulmonary embolism among patients with syncope is understudied. In accordance with a recent study with an exceptionally high pulmonary embolism prevalence, some advocate evaluating all syncope patients for pulmonary embolism, including those with another clear cause for their syncope. We seek to evaluate the pulmonary embolism prevalence among emergency department (ED) patients with syncope. METHODS: We combined data from 2 large prospective studies enrolling adults with syncope from 17 EDs in Canada and the United States. Each study collected the results of pulmonary embolism-related investigations (ie, D-dimer, ventilation-perfusion scan, or computed tomography [CT] pulmonary angiography) and 30-day adjudicated outcomes: pulmonary embolism or nonpulmonary embolism outcome (arrhythmia, myocardial infarction, serious hemorrhage, and death). RESULTS: Of the 9,374 patients enrolled, 9,091 (97.0%; median age 66 years, 51.9% women) with 30-day follow-up were analyzed: 547 (6.0%) were evaluated for pulmonary embolism (278 [3.1%] had D-dimer, 39 [0.4%] had ventilation-perfusion scan, and 347 [3.8%] had CT pulmonary angiography). Overall, 874 patients (9.6%) experienced 30-day serious outcomes: 818 patients (9.0%) with nonpulmonary embolism serious outcomes and 56 (prevalence 0.6%; 95% confidence interval 0.5% to 0.8%) with pulmonary embolism (including 8 [0.2%] out of 3521 patients diagnosed during the index hospitalization and 7 [0.1%] diagnosed after the index visit). Eighty-six patients (0.9%) died, and 4 deaths (0.04%) were related to pulmonary embolism. Only 11 patients (0.1%) with a nonpulmonary embolism serious condition had a concomitant pulmonary embolism. CONCLUSION: The prevalence of pulmonary embolism is very low among ED patients with syncope, including those hospitalized after syncope. Although an underlying pulmonary embolism may cause syncope, clinicians should be cautious about indiscriminate investigations for pulmonary embolism.

Evaluation of an emergency department to outpatient parenteral antibiotic therapy program for cellulitis.

OBJECTIVE: Emergency department (ED) patients with non-purulent skin and soft tissue infections (SSTIs) requiring intravenous antibiotics may be managed via outpatient parenteral antibiotic therapy (OPAT). Prospective studies describing the performance of an ED-to-OPAT clinic program are lacking. The primary objective was to determine the OPAT treatment failure rate for ED patients with non-purulent SSTIs. METHODS: We conducted a prospective observational cohort study of adults with non-purulent SSTIs managed via an ED-to-OPAT clinic program. OPAT treatment failure was defined as hospitalization after a minimum of 48 h of OPAT for: worsening infection; intravenous line complications; or adverse antibiotic effects. Secondary outcomes were to describe OPAT clinic processes, patient satisfaction, and physician rationale for selecting intravenous antibiotics. RESULTS: We enrolled a consecutive sample of 153 patients [mean age 60.5 years, 82 male (53.6%)]; 137 patients (89.5%) attended their clinic appointment. OPAT treatment failure was 4.4%. None of the adverse intravenous line (10.9%) and adverse antibiotic (8.0%) events required hospitalization. Patients reported high satisfaction with timeliness of referral (median score 9 out of 10) and overall care received (median score of 10). The top five reasons given by physicians for selecting intravenous therapy were: clinical impression (52.9%); failed oral therapy (41.8%); diabetes (17.6%); severe pain (7.8%); and peripheral vascular disease (7.8%). CONCLUSIONS: This prospective study demonstrates that an ED-to-OPAT clinic program for non-purulent SSTIs is safe, has a low rate of treatment failures and results in high patient satisfaction. The rationale for selecting intravenous antibiotics showed significant variability among ED physicians.

Diagnostic Accuracy and Financial Implications of Age-Adjusted D-Dimer Strategies for the Diagnosis of Deep Venous Thrombosis in the Emergency Department.

BACKGROUND: Multiple D-dimer cutoffs have been suggested for older patients to improve diagnostic specificity for venous thromboembolism. These approaches are better established for pulmonary embolism. OBJECTIVES: We evaluated the diagnostic performance and compared the health system cost for previously suggested cutoffs and a new D-dimer cutoff for low-risk emergency department (ED) deep venous thrombosis (DVT) patients. METHODS: We conducted a retrospective cohort study in two large EDs involving patients aged > 50 years who had low pretest probability for DVT and had a D-dimer performed. The outcome was a diagnosis of DVT at 30 days. We evaluated the diagnostic accuracy and estimated the difference in cost for cutoffs of 500 ng/mL and the age-adjusted (age × 10) rule. A derived cutoff of 1000 ng/mL was also assessed. RESULTS: Nine hundred and seventy-two patients were included (median age 66 years; 59.5% female); 63 (6.5%) patients were diagnosed with DVT. The conventional cutoff of < 500 ng/mL demonstrated a sensitivity of 100% (95% confidence interval [CI] 94.3-100%) and a specificity of 35.6% (95% CI 32.5-38.8%). The age-adjusted approach increased specificity while maintaining high sensitivity. A new cutoff of 1000 ng/mL demonstrated improved performance: sensitivity 100% (95% CI 94.3-00%) and specificity 66.3% (95% CI 63.2-69.4%). Compared to the conventional approach, both the 1000 ng/mL cutoff and the age-adjusted cutoffs could save healthcare dollars. A cutoff of 1000 ng/mL could have saved 310 ED length of stay hours and $166,909 (Canadian dollars) in our cohort, or an average savings of 0.32 h and $172 per patient. CONCLUSIONS: Among patients aged > 50 years with suspected DVT, the age-adjusted D-dimer and a cutoff of 1000 ng/mL improved specificity without compromising sensitivity, and lowered the health care system cost compared to that for the conventional approach.

Pacing as a Treatment for Reflex-Mediated (Vasovagal, Situational, or Carotid Sinus Hypersensitivity) Syncope: A Systematic Review for the 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society.

OBJECTIVES: To determine, using systematic review of the biomedical literature, whether pacing reduces risk of recurrent syncope and relevant clinical outcomes among adult patients with reflex-mediated syncope. METHODS: MEDLINE (through PubMed), EMBASE, and the Cochrane Central Register of Controlled Trials (through October 7, 2015) were searched for randomized trials and observational studies examining pacing and syncope, and the bibliographies of known systematic reviews were also examined. Studies were rejected for poor-quality study methods and for the lack of the population, intervention, comparator, or outcome(s) of interest. RESULTS: Of 3188 citations reviewed, 10 studies met the inclusion criteria for systematic review, including a total of 676 patients. These included 9 randomized trials and 1 observational study. Of the 10 studies, 4 addressed patients with carotid sinus hypersensitivity, and the remaining 6 addressed vasovagal syncope. Among the 6 open-label (unblinded) studies, we found that pacing was associated with a 70% reduction in recurrent syncope (relative risk [RR]: 0.30; 95% confidence interval [CI]: 0.15-0.60). When the 2 analyzable studies with double-blinded methodology were considered separately, there was no clear benefit (RR: 0.73; 95% CI: 0.25-2.1), but confidence intervals were wide. The strongest evidence was from the randomized, double-blinded ISSUE-3 (Third International Study on Syncope of Uncertain Etiology) trial, which demonstrated a benefit of pacing among patients with recurrent syncope and asystole documented by implantable loop recorder. CONCLUSIONS: There are limited data with substantive evidence of outcome ascertainment bias, and only 2 studies with a double-blinded study design have been conducted. The evidence does not support the use of pacing for reflex-mediated syncope beyond patients with recurrent vasovagal syncope and asystole documented by implantable loop recorder.

Application of outpatient cardiac testing among emergency department patients with syncope.

OBJECTIVES: 2.6% of ED syncope patients will suffer cardiac serious adverse events (SAEs) within 30 days of disposition, and outpatient cardiac testing can improve patient safety. The objective is to determine whether outpatient cardiac testing for ED syncope patients is being appropriately ordered after discharge. To this end, we describe the proportion of high-risk and non-high (low and medium)-risk ED syncope patients as per the Canadian Syncope Risk Score (CSRS) who have a SAE after ED discharge, and the proportion referred for outpatient cardiac testing. METHODS: Our multicentre prospective cohort study enrolled adult syncope patients between 2010 and 2014 in five academic EDs. We collected patient characteristics, disposition, CSRS predictors, outpatient referrals and testing results (Holter, echocardiography), and 30-day adjudicated SAE (death due to unknown/cardiac cause, myocardial infarction, arrhythmia and structural heart disease). We used descriptive statistics (mean, SD) to report our results. RESULTS: Of 3584 enrolled patients (mean age 50.9 years, 57.7% women), 800 patients (22.3%) received an outpatient referral. Of these 800 patients, 40.3% of the non-high-risk patients (305/756) and 54.5% of the high-risk patients (24/44) received outpatient cardiac testing. Of all patients who received cardiac testing, five (1.5%; 95% CI 0.6% to 3.5%) suffered outpatient SAE (60.0% arrhythmias). Of all patients who did not receive cardiac testing, four patients (0.9%; 95% CI 0.3% to 2.2%) suffered SAE (all arrhythmias). Of the 20 (45.5%) high-risk patients who did not receive testing, two patients (10.0%; 95% CI 2.8% to 30.1%) suffered arrhythmias outside the hospital, while among the 451 (59.7%) non-high-risk patients, only two (0.4%; 95% CI 0.1% to 1.6%) suffered outpatient arrhythmias. CONCLUSION: Outpatient cardiac testing is largely underused, especially among high-risk ED syncope patients. Better guidelines for outpatient cardiac testing are needed, as the practice is highly variable and mismatched with patient risk.

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.