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.

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.

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.

ABSTRAIT: CONTEXTE: Pour les patients du service des urgences (DE) atteints de syncope, la troponine cardiaque peut identifier le syndrome coronarien aigu (SCA) et le pronostic pour les événements indésirables graves de 30 jours. Cependant, il n'est pas clair si les tests en série améliorent le rendement diagnostique et le pronostic. MéTHODES: Il s'agissait d'une analyse secondaire des données de deux études prospectives menées pour élaborer le Canadian Syncope Risk Score. Des adultes (âgés de 16 ans) atteints de syncope ont été recrutés, et les caractéristiques du patient, les signes vitaux, l'empreinte diagnostique du médecin, les résultats de l'électrocardiogramme et de la troponine, ainsi que les événements indésirables graves évalués à 30 jours ont été recueillis. Le critère de jugement principal était la détection d'un événement indésirable grave dans les 30 jours suivant la décision de l'urgence. Le critère de jugement secondaire était la comparaison de la durée de séjour à l'urgence chez les patients ayant une seule mesure de troponine par rapport à la mesure en série. RéSULTATS: 4 996 patients [âge moyen 64,5 (ET 18,8) ans, 52,2 % d'hommes] ont été inclus : 4 397 (89,8 %) avec une seule troponine [232 (5,3 %) avec un événement indésirable grave à l'urgence et 203 (4,6 %) après l'urgence]; 499 (10,2 %) patients avec > 1 mesure de la troponine [39 (7,8 %) avec événement indésirable grave à l'urgence et 60 (12,0 %) après la décision à l'urgence]. Parmi les patients ayant fait l'objet de mesures en série, 10 (2,0 %) présentaient une augmentation du seuil inférieur à supérieur au seuil du 99e percentile, dont 4 (0,8 %) ont subi un événement indésirable grave : deux avec arythmies diagnostiquées par électrocardiogramme, un avec SCA et un avec insuffisance respiratoire. Neuf patients (1,8 %) ont présenté une reclassification du risque selon le score canadien de risque de syncope en fonction de la mesure en série, et aucun n'a subi d'événement indésirable grave de 30 jours. La durée médiane de séjour aux urgences était significativement plus longue pour les patients ayant subi des tests en série (5,6 vs. 3,8 heures, p < 0,001). CONCLUSIONS: La mesure initiale de la troponine était suffisante pour la détection des effets indésirables graves et la stratification des risques aux urgences. Les tests de troponine en série n'améliorent pas le rendement diagnostique ou le pronostic et doivent être réservés aux patients présentant des symptômes continus ou des résultats d'électrocardiogramme suggérant une ischémie cardiaque.

Development of practice recommendations based on the Canadian Syncope Risk Score and identification of barriers and facilitators for implementation.

BACKGROUND: Wide variations in emergency department (ED) syncope management exist. The Canadian Syncope Risk Score (CSRS) was developed to predict the probability of 30-day serious outcomes after ED disposition. Study objectives were to evaluate the acceptability of proposed CSRS practice recommendations among providers and patients, and identify barriers and facilitators for CSRS use to guide disposition decisions. METHODS: We conducted semi-structured interviews with 41 physicians involved in ED syncope and 35 ED patients with syncope. We used purposive sampling to ensure a variety of physician specialties and CSRS patient risk levels. Thematic analysis was completed by two independent coders with consensus meetings to resolve conflicts. Analysis proceeded in parallel with interviews until data saturation. RESULTS: The majority (97.6%; 40/41) of physicians agreed with discharge of low risk (CSRS ≤ 0) but opined that 'no follow up' changed to 'follow-up as needed'. Physicians indicated current practices do not align with the medium-risk recommendation to discharge patients with 15-day monitoring (CSRS = 1-3; due to lack of access to monitors and timely follow-up) and the high-risk recommendation (CSRS ≥ 4) to potentially discharge patients with 15-day monitoring. Physicians recommended brief hospitalization of high-risk patients due to patient safety concerns. Facilitators included the CSRS-based patient education and scores supporting their clinical gestalt. Patients reported receiving varying levels of information regarding syncope and post-ED care, were satisfied with care received and preferred less resource intensive options. CONCLUSION: Our recommendations based on the study results were: discharge of low-risk patients with physician follow-up as needed; discharge of medium-risk patients with 15-day cardiac monitoring and brief hospitalization of high-risk patients with 15-day cardiac monitoring if discharged. Patients preferred less resource intensive options, in line with CSRS recommended care. Implementation should leverage identified facilitators (e.g., patient education) and address the barriers (e.g., monitor access) to improve ED syncope care.

RéSUMé: CONTEXTE: La prise en charge des syncopes par les services d'urgence varie considérablement. Le Canadian Syncope Risk Score (CSRS) a été mis au point pour prédire la probabilité d'une issue grave à 30 jours après la prise en charge par le service des urgences. Les objectifs de l'étude étaient d'évaluer l'acceptabilité des recommandations pratiques proposées par le CSRS parmi les prestataires et les patients, et d'identifier les barrières et les facilitateurs de l'utilisation du CSRS pour guider les décisions de disposition. MéTHODES: Nous avons mené des entretiens semi-structurés avec 41 médecins impliqués dans la syncope aux urgences et 35 patients souffrant de syncope aux urgences. Nous avons utilisé un échantillonnage raisonné pour assurer une variété de spécialités médicales et de niveaux de risque pour les patients du CSRS. L'analyse thématique a été réalisée par deux codeurs indépendants, avec des réunions de consensus pour résoudre les conflits. L'analyse s'est déroulée parallèlement aux entretiens jusqu'à saturation des données. RéSULTATS: La majorité (97,6 % ; 40/41) des médecins étaient d'accord avec la sortie des patients à faible risque (CSRS ≤ 0), mais ont estimé que " pas de suivi " devait être remplacée par " suivi en fonction des besoins ". Les médecins ont indiqué que leurs pratiques actuelles ne sont pas conformes à la recommandation à risque moyen de faire sortir les patients avec une surveillance de 15 jours (CSRS = 1-3 ; en raison du manque d'accès aux moniteurs et au suivi en temps opportun) et à la recommandation à risque élevé (CSRS ≥ 4) de potentiellement faire sortir les patients avec une surveillance de 15 jours. Les médecins ont recommandé une brève hospitalisation des patients à haut risque pour des raisons de sécurité. Les facilitateurs comprenaient l'éducation des patients basée sur le CSRS et les scores soutenant leur gestalt clinique. Les patients ont déclaré avoir reçu différents niveaux d'information concernant la syncope et les soins post-urgence, étaient satisfaits des soins reçus et préféraient des options moins gourmandes en ressources. CONCLUSIONS: Nos recommandations basées sur les résultats de l'étude sont les suivantes : sortie des patients à faible risque avec suivi par un médecin si nécessaire ; la sortie des patients à risque moyen avec une surveillance cardiaque de 15 jours et une brève hospitalisation des patients à risque élevé avec une surveillance cardiaque de 15 jours en cas de sortie. Les patients ont préféré des options moins gourmandes en ressources, conformément aux soins recommandés par le CSRS. La mise en œuvre devrait s'appuyer sur les facilitateurs identifiés (par exemple, l'éducation des patients) et s'attaquer aux obstacles (par exemple, le contrôle de l'accès) pour améliorer les soins aux urgences en cas de syncope.

Multicenter Emergency Department Validation of the Canadian Syncope Risk Score.

Importance: The management of patients with syncope in the emergency department (ED) is challenging because no robust risk tool available has been recommended for clinical use. Objective: To validate the Canadian Syncope Risk Score (CSRS) in a new cohort of patients with syncope to determine its ability to predict 30-day serious outcomes not evident during index ED evaluation. Design, Setting, and Participants: This prospective multicenter cohort study conducted at 9 EDs across Canada included patients 16 years and older who presented to EDs within 24 hours of syncope. Patients were enrolled from March 2014 to April 2018. Main Outcomes and Measures: Baseline characteristics, CSRS predictors, and 30-day adjudicated serious outcomes, including arrhythmic (arrhythmias, interventions for arrhythmia, or unknown cause of death) and nonarrhythmic (myocardial infarction, structural heart disease, pulmonary embolism, or hemorrhage) serious outcomes, were collected. Calibration and discrimination characteristics for CSRS validation were calculated. Results: A total of 3819 patients were included (mean [SD] age 53.9 [22.8] years; 2088 [54.7%] female), of whom 139 (3.6%) experienced 30-day serious outcomes, including 13 patients (0.3%) who died. In the validation cohort, there were no differences between the predicted and observed risk, the calibration slope was 1.0, and the area under the receiver operating characteristic curve was 0.91 (95% CI, 0.88-0.93). The empirical probability of a 30-day serious outcome during validation was 3.64% (95% CI, 3.09%-4.28%) compared with the model-predicted probability of 3.17% (95% CI, 2.66%-3.77%; P = .26). The proportion of patients with 30-day serious outcomes increased from 3 of 1631 (0.3%) in the very-low-risk group to 40 of 78 (51.3%) in the very-high-risk group (Cochran-Armitage trend test P < .001). There was a similar significant increase in the serious outcome subtypes with increasing CSRS risk category. None of the very-low-risk and low-risk patients died or experienced ventricular arrhythmia. At a threshold score of -1 (2145 of 3819 patients), the CSRS sensitivity and specificity were 97.8% (95% CI, 93.8%-99.6%) and 44.3% (95% CI, 42.7%-45.9%), respectively. Conclusions and Relevance: The CSRS was successfully validated and its use is recommended to guide ED management of patients when serious causes are not identified during index ED evaluation. Very-low-risk and low-risk patients can generally be discharged, while brief hospitalization can be considered for high-risk patients. We believe CSRS implementation has the potential to improve patient safety and health care efficiency.