Risk Scores for Clinical Risk Stratification of Emergency Department Patients With Chest Pain but No Acute Myocardial Infarction: A Systematic Review.

BACKGROUND: Chest pain is a common cause for emergency department (ED) presentations. After myocardial infarction (MI) has been ruled out by means of electrocardiography and troponin testing, decisions around anatomic or functional testing may be informed by clinical risk scores. We conducted a systematic review to synthesize evidence of the prognostic performance of chest pain risk scores among ED patients who have had MI ruled out by means of a high-sensitivity troponin assay. METHODS: We queried multiple databases from inception to May 17, 2022. We included studies that quantified risk of 30-day major adverse cardiac events (MACE), at different cutoffs of clinical risk scores, among adult patients who had MI ruled out by means of a high-sensitivity troponin assay. Prognostic performance of each score was synthesized and described, but meta-analysis was not possible. RESULTS: Six studies met inclusion criteria. Short-term MACE risk among patients who had MI ruled out by means of high-sensitivity cardiac troponin assays was very low. The HEART score, with a cutoff of 3 or less, predicted a very low risk of MACE among the greatest proportion of patients. Other scores had lower sensitivity or classified fewer patients as low risk. CONCLUSIONS: The HEART score with a cutoff value of 3 or less accurately identified the greatest number of patients at low risk of 30-day MACE. However, MACE risk among patients who have MI ruled out by means of high-sensitivity troponin testing is sufficiently low that clinical risk stratification or noninvasive testing may be of little additional value in identifying patients with coronary disease.

Effectiveness of intravenous prostaglandin to reduce digital amputations from frostbite: an observational study.

PURPOSE: We assessed the effectiveness and safety of a 5-day intravenous prostaglandin (iloprost) protocol at reducing digital amputation for patients with severe frostbite injuries at urban emergency departments. METHODS: This retrospective study examines consecutive patients who presented to Calgary emergency departments from April 2017 to April 2020 with Grade 2-4 frostbite injuries. Patients from February 2019 onward were managed using a 5-day iloprost infusion protocol, whereas patients prior to this time were managed with standard care (local best practice without iloprost as a therapeutic option). The primary effectiveness outcome was rate of affected digits amputated, stratified by frostbite severity. The secondary safety outcome was the incidence of serious adverse events associated with iloprost (allergic reactions or symptomatic hypotension requiring treatment or discontinuation of the infusion). RESULTS: 90 patients were included, 26 were treated with iloprost, compared to 64 patients who received usual care. Both the treatment and usual care groups experienced substantial rates of homelessness and substance use. No digital amputations were required for patients with Grade 2 injuries in either group, but significantly lower digital amputation rates were observed for patients with more severe frostbite injuries treated with iloprost versus usual care: Grade 3 (18% vs 44%, p < 0.001), Grade 4 (46% vs 95%, p < 0.001). No serious adverse events were associated with iloprost. CONCLUSION: In this unselected socially complex urban population, administration of iloprost for patients with frostbite was shown to be safe and was associated with lower digital amputation rates, particularly for those with more severe injuries.

RéSUMé: OBJECTIF: Nous avons évalué l'efficacité et la sécurité d'un protocole de 5 jours de prostaglandine intraveineuse (iloprost) pour réduire l'amputation digitale chez les patients souffrant d'engelures graves dans les services d'urgence urbains. MéTHODES: Cette étude rétrospective examine des patients consécutifs qui se sont présentés aux services d'urgence de Calgary d'avril 2017 à avril 2020 avec des engelures de niveau 2 à 4. À compter de février 2019, les patients ont été traités au moyen d'un protocole de perfusion d'iloprost de 5 jours, tandis que les patients avant cette période ont été pris en charge avec des soins standard (meilleures pratiques locales sans iloprost comme option thérapeutique). Le principal résultat d'efficacité était le taux de doigts affectés amputés, stratifié selon la gravité des gelures. Le critère secondaire de sécurité était l'incidence des événements indésirables graves associés à l'iloprost (réactions allergiques ou hypotension symptomatique nécessitant un traitement ou l'arrêt de la perfusion). RéSULTATS: 90 patients ont été inclus, 26 ont été traités avec de l'iloprost, contre 64 patients qui ont reçu les soins habituels. Les groupes de traitement et de soins habituels ont tous deux connu des taux importants de sans-abrisme et de consommation de substances. Aucune amputation digitale n'a été nécessaire pour les patients présentant des lésions de grade 2 dans l'un ou l'autre groupe, mais des taux d'amputation digitale significativement plus faibles ont été observés pour les patients présentant des lésions de gelures plus sévères traités par iloprost par rapport aux soins habituels : Grade 3 (18 % contre 44 %, p < 0,001), Grade 4 (46 % contre 95 %, p < 0,001). Aucun événement indésirable grave n'a été associé à l'iloprost. CONCLUSION: Dans cette population urbaine non sélectionnée et socialement complexe, l'administration d'iloprost pour les patients souffrant d'engelures s'est avérée sûre et a été associée à des taux d'amputation digitale plus faibles, en particulier pour ceux présentant des blessures plus graves.

External validation of a low HEAR score to identify emergency department chest pain patients at very low risk of major adverse cardiac events without troponin testing.

BACKGROUND: The history, ECG, age, risk factor (HEAR) score has been proposed to identify patients at sufficiently low risk of acute coronary syndrome that they may not require troponin testing. The objective of this study was to externally validate a low HEAR score to identify emergency department (ED) patients with chest pain at very low risk of 30-day major adverse cardiac events (MACE). METHODS: This was a secondary analysis of a prospective cohort of patients requiring troponin testing to rule out myocardial infarction (MI) in a large urban ED. HEAR scores were calculated in two cohorts: (1) patients with no known history of coronary artery disease (CAD); and (2) all eligible patients. The proportion of patients classified as very low risk, sensitivity, specificity, predictive values and likelihood ratios at each cut-off were quantified for index acute myocardial infarction (AMI) and 30-day MACE at HEAR = 0 and HEAR ≤ 1 thresholds. RESULTS: Of the 1150 patients included in this study, 820 (71.3%) had no history of CAD, 97 (8.4%) had index AMI and 123 (10.7%) had 30-day MACE. In patients with no prior history of CAD, HEAR ≤ 1 identified 202 (24.6%) of patients as very low risk for 30-day MACE with 98.4% (95% CI 91.6-99.9%) sensitivity. Among all patients, HEAR ≤ 1 identified 202 (17.6%) patients as very low risk for 30-day MACE with 99.2% (95% CI 95.6-99.9%) sensitivity. CONCLUSIONS: A HEAR score ≤ 1 can identify more than 17% of all patients as very low risk for index AMI and 30-day MACE and unlikely to benefit from troponin testing. Broad implementation of this strategy could lead to significant resource savings.

RéSUMé: CONTEXTE: Le score HEAR (History, ECG, Age, Risk Factor) a été proposé pour identifier les patients présentant un risque suffisamment faible de syndrome coronarien aigu pour ne pas nécessiter de test à la troponine. L'objectif de cette étude était de valider à l'externe un faible score HEAR afin d'identifier les patients du service d'urgence (DE) souffrant de douleurs thoraciques à très faible risque d'événements cardiaques indésirables majeurs (MACE) de 30 jours. MéTHODES: Il s'agissait d'une analyse secondaire d'une cohorte prospective de patients nécessitant un test à la troponine pour exclure un infarctus du myocarde (IM) dans un grand service d'urgence urbain. Les scores HEAR ont été calculés dans deux cohortes : (1) les patients sans antécédents connus de maladie coronarienne (MC) ; et (2) tous les patients éligibles. La proportion de patients classés à très faible risque, la sensibilité, la spécificité, les valeurs prédictives et les rapports de vraisemblance à chaque seuil ont été quantifiés pour l'infarctus aigu du myocarde (IAM) de l'index et la MACE à 30 jours aux seuils HEAR = 0 et HEAR ≤ 1. RéSULTATS: Sur les 1 150 patients inclus dans cette étude, 820 (71.3%) n'avaient pas d'antécédents de coronaropathie, 97 (8.4%) avaient un IAM index et 123 (10.7%) avaient une MACE à 30 jours. Chez les patients sans antécédents de coronaropathie, HEAR ≤ 1 a identifié 202 (24,6%) des patients comme présentant un très faible risque de MACE à 30 jours avec une sensibilité de 98.4% (IC 95% 91.6­99.9%). Parmi tous les patients, HEAR ≤ 1 a identifié 202 (17.6%) patients comme présentant un très faible risque de MACE à 30 jours avec une sensibilité de 99.2% (IC 95% 95.6­99.9%). CONCLUSIONS: Un score HEAR ≤ 1 peut identifier plus de 17% de tous les patients comme étant à très faible risque d'IAM d'index et de MACE à 30 jours et peu susceptibles de bénéficier d'un test à la troponine. La mise en œuvre à grande envergure de cette stratégie pourrait permettre de réaliser d'importantes économies de ressources.

Does early intervention improve outcomes for patients with acute ureteral colic?

OBJECTIVES: Early surgical intervention is increasingly employed for patients with ureteral colic, but guidelines and current practice are variable. We compared 60-day outcomes for matched patients undergoing early intervention vs. spontaneous passage. METHODS: This multicentre propensity-matched cohort analysis used administrative data and chart review to study all eligible emergency department (ED) patients with confirmed 2.0-9.9 mm ureteral stones. Those having planned stone intervention within 5 days comprised the intervention cohort. Controls attempting spontaneous passage were matched to intervention patients based on age, sex, stone width, stone location, hydronephrosis, ED site, ambulance arrival and acuity level. The primary outcome was treatment failure, defined as rescue intervention or hospitalization within 60 days, using a time to event analysis. Secondary outcome was ED revisit rate. RESULTS: Among 1154 matched patients, early intervention did not reduce the risk of treatment failure (adjusted hazard ratio 0.94; P = 0.61). By 60 days, 21.8% of patients in both groups experienced the composite primary outcome (difference 0.0%; 95% confidence interval - 4.8 to 4.8%). Intervention patients required more hospitalizations (20.1% vs. 12.8%; difference 7.3%; 95% CI 3.0-11.5%) and ED revisits (36.1% vs. 25.5%; difference 10.6%; 95% CI 5.3-15.9%), but (insignificantly) fewer rescue interventions (18.9% vs. 21.3%; difference - 2.4%; 95% CI - 7.0 to 2.2%). CONCLUSIONS: In matched patients with 2.0-9.9 mm ureteral stones, early intervention was associated with similar rates of treatment failure but greater patient morbidity, evidenced by hospitalizations and emergency revisits. Physicians should adopt a selective approach to interventional referral and consider that spontaneous passage probably provides better outcomes for many low-risk patients.

RéSUMé: OBJECTIFS: L'intervention chirurgicale précoce est de plus en plus utilisée pour les patients atteints de coliques urétérales, mais les lignes directrices et la pratique actuelle sont variables. Nous avons comparé les résultats à 60 jours pour les patients appariés subissant une intervention précoce par rapport au passage spontané. LES MéTHODES: Cette analyse de cohorte multicentrique par appariement de propension a utilisé des données administratives et l'examen des dossiers pour étudier tous les patients admissibles des services d'urgence (ED) ayant des calculs urétéraux confirmés de 2,0-9,9 mm Ceux qui avaient planifié une intervention de calcul dans les cinq jours constituaient la cohorte d'intervention. Les témoins tentant de passer spontanément ont été appariés aux patients d'intervention en fonction de l'âge, du sexe, de la largeur du calcul, de l'emplacement du calcul, de l'hydronéphrose, du site de l'urgence, de l'arrivée de l'ambulance et du niveau d'acuité. Le résultat principal était l'échec de traitement, défini comme l'intervention de sauvetage ou l'hospitalisation dans les 60 jours, utilisant un temps à l'analyse d'événement. Le résultat secondaire était le taux de revisite à l'urgence RéSULTATS: Sur 1154 patients appariés, une intervention précoce n'a pas réduit le risque d'échec du traitement (ratio de risque ajusté = 0,94 ; P = 0,61). Au bout de 60 jours, 21,8 % des patients des deux groupes avaient atteint le résultat primaire composite (différence = 0,0 % ; intervalle de confiance à 95 % -4,8 % à 4,8 %). Les patients d'intervention ont nécessité plus d'hospitalisations (20,1 % contre 12,8 % ; différence = 7,3 % ; IC 95 %, 3,0 à 11,5 %) et de nouvelles visites à l'urgence (36,1 % contre 25,5 % ; différence = 10,6 % ; IC 95 %, 5,3 à 15,9 %), mais (de manière non significative) moins d'interventions de sauvetage (18,9 % contre 21,3 % ; différence = 2,4 % ; IC 95 %, -7,0 à 2,2 %). CONCLUSIONS: Chez des patients appariés présentant des calculs urétéraux de 2,0 à 9,9 mm, l'intervention précoce a été associée à des taux similaires d'échec du traitement mais à une morbidité plus importante des patients, comme en témoignent les hospitalisations et les revisites aux urgences. Les médecins devraient adopter une approche sélective de l'orientation interventionnelle et considérer que le passage spontané offre probablement de meilleurs résultats pour de nombreux patients à faible risque.

Decision support for computed tomography in the emergency department: a multicenter cluster-randomized controlled trial.

OBJECTIVES: Clinical decision support may facilitate evidence-based imaging, but most studies to date examining the impact of decision support have used non-randomized designs which limit the conclusions that can be drawn from them. This randomized trial examines if decision support can reduce computed tomography (CT) utilization for patients with mild traumatic brain injuries and suspected pulmonary embolism in the emergency department. This study was funded by a competitive public research grant and registered on ClinicalTrials.gov (NCT02410941). METHODS: Emergency physicians at five urban sites were assigned to voluntary decision support for CT imaging of patients with either head injuries or suspected pulmonary embolism using a cluster-randomized design over a 1-year intervention period. The co-primary outcomes were CT head and CT pulmonary angiography utilization. CT pulmonary angiography diagnostic yield (proportion of studies diagnostic for acute pulmonary embolism) was a secondary outcome. RESULTS: A total of 225 physicians were randomized and studied over a 2-year baseline and 1-year intervention period. Physicians interacted with the decision support in 38.0% and 45.0% of eligible head injury and suspected pulmonary embolism cases, respectively. A mixed effects logistic regression model demonstrated no significant impact of decision support on head CT utilization (OR 0.93, 95% CI 0.79-1.10, p = 0.31), CT pulmonary angiography utilization (OR 0.98, 95% CI 0.88-1.11, p = 0.74) or diagnostic yield (OR 1.23, 95% CI 0.96-1.65, p = 0.10). However, overall CT pulmonary diagnostic yield (17.7%) was almost three times higher than that reported by a recent large US study, suggesting that selective imaging was already being employed. CONCLUSION: Voluntary decision support addressing many commonly cited barriers to evidence-based imaging did not significantly reduce CT utilization or improve diagnostic yield but was limited by low rates of participation and high baseline rates of selective imaging. Demonstrating value to clinicians through interventions that improve workflow is likely necessary to meaningfully change imaging practices.

RéSUMé: OBJECTIFS: Le soutien à la décision clinique peut faciliter l'imagerie fondée sur des données probantes, mais la plupart des études à ce jour examinant l'impact du soutien à la décision ont utilisé des modèles non randomisés qui limitent les conclusions qui peuvent en être tirées. Cet essai randomisé examine si l'aide à la décision peut réduire l'utilisation de la tomodensitométrie chez les patients présentant des lésions cérébrales traumatiques légères et une embolie pulmonaire présumée au service des urgences. Cette étude a été financée par une subvention de recherche publique compétitive et enregistrée sur ClinicalTrials.gov (NCT02410941). MéTHODES: Les médecins urgentistes de cinq sites urbains ont été assignés à une aide à la décision volontaire pour l'imagerie par tomodensitométrie des patients présentant soit un traumatisme crânien, soit une suspicion d'embolie pulmonaire, selon une conception randomisée en grappes sur une période d'intervention d'un an. Les résultats co-primaires étaient l'utilisation de la tomodensitométrie de la tête et de la tomodensitométrie par angiographie pulmonaire. Le rendement diagnostique de l'angiographie pulmonaire par TDM (proportion d'études diagnostiquant une embolie pulmonaire aiguë) était un résultat secondaire. RéSULTATS: Au total, 225 médecins ont été randomisés et étudiés au cours d'une période de référence de deux ans et d'une période d'intervention d'un an. Les médecins ont interagi avec l'aide à la décision dans 38,0 % et 45,0 % des cas admissibles de blessure à la tête et d'embolie pulmonaire soupçonnée, respectivement. Un modèle de régression logistique à effets mixtes n'a démontré aucun impact significatif de l'aide à la décision sur l'utilisation de la tomodensitométrie de la tête (OR 0,93, IC 95 % 0,79-1,10, p = 0,31), l'utilisation de l'angiographie pulmonaire par tomodensitométrie (OR 0,98, IC 95 % 0,88-1,11, p = 0,74) ou le rendement diagnostique (OR 1,23, IC 95 % 0,96-1,65, p = 0,10). Toutefois, le rendement global du diagnostic pulmonaire par TDM (17,7 %) était près de trois fois supérieur à celui rapporté par une étude récente aux États-Unis, ce qui laisse supposer que l'imagerie sélective était déjà utilisée. CONCLUSIONS: L'aide à la décision volontaire visant à éliminer de nombreux obstacles fréquemment cités à l'imagerie fondée sur des données probantes n'a pas réduit de façon significative l'utilisation de la tomodensitométrie ni amélioré le rendement diagnostique, mais a été limitée par de faibles taux de participation et des taux de base élevés d'imagerie sélective. La démonstration de la valeur pour les cliniciens par des interventions qui améliorent le flux de travail est probablement nécessaire pour changer de manière significative les pratiques d'imagerie.

Personal protective equipment preservation strategies in the covid-19 era: A narrative review.

BACKGROUND: The COVID-19 pandemic has led to personal protective equipment (PPE) supply concerns on a global scale. While efforts to increase production are underway in many jurisdictions, demand may yet outstrip supply leading to PPE shortages, particularly in low resource settings. PPE is critically important for the safety of healthcare workers (HCW) and patients and to reduce viral transmission within healthcare facilities. A structured narrative review was completed to identify methods for extending the use of available PPE as well as decontamination and reuse. METHODS: Database searches were conducted in MEDLINE and EMBASE for any available original research or review articles detailing guidelines for the safe extended use of PPE, and/or PPE decontamination and reuse protocols prior to September 28, 2020. Grey literature in addition to key websites from the Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), Infection Prevention Association of Canada (IPAC), and the National Health Service (NHS) was also reviewed. RESULTS: Extended use guidelines support co-locating patients with confirmed COVID-19 within specific areas of healthcare facilities to enable the use of PPE between multiple patients, and reduce PPE requirements outside these areas. Decontamination strategies for N95 respirators and face shields range from individual HCWs using conventional ovens and microwave steam bags at home, to large-scale centralized decontamination using autoclave machines, ultraviolet germicidal irradiation, hydrogen peroxide vapors, or peracetic acid dry fogging systems. Specific protocols for such strategies have been recommended by the US CDC and WHO and are being implemented by multiple institutions across North America. Further studies are underway testing decontamination strategies that have been reported to be effective at inactivating coronavirus and influenza, and on SARs-CoV-2 specifically. CONCLUSIONS: This narrative review summarizes current extended use guidelines and decontamination protocols specific to COVID-19. Preserving PPE through the implementation of such strategies could help to mitigate shortages in PPE supply, and enable healthcare facilities in low resource settings to continue to operate safely for the remainder of the COVID-19 pandemic.

Rapid prediction of adverse outcomes for acute normotensive pulmonary embolism: derivation of the Calgary Acute Pulmonary Embolism score.

BACKGROUND: Acute pulmonary embolism (PE) has a wide spectrum of outcomes, but the best method to risk-stratify normotensive patients for adverse outcomes remains unclear. METHODS: A multicentre retrospective cohort study of acute PE patients admitted from emergency departments in Calgary, Canada, between 2012 and 2017 was used to develop a refined acute PE risk score. The composite primary outcome of in-hospital PE-related death or haemodynamic decompensation. The model was internally validated using bootstrapping and the prognostic value of the derived risk score was compared to the Bova score. RESULTS: Of 2067 patients with normotensive acute PE, the primary outcome (haemodynamic decompensation or PE-related death) occurred in 32 (1.5%) patients. In simplified Pulmonary Embolism Severity Index high-risk patients (n=1498, 78%), a multivariable model used to predict the primary outcome retained computed tomography (CT) right-left ventricular diameter ratio ≥1.5, systolic blood pressure 90-100 mmHg, central pulmonary artery clot and heart rate ≥100 beats·min-1 with a C-statistic of 0.89 (95% CI 0.82-0.93). Three risk groups were derived using a weighted score (score, prevalence, primary outcome event rate): group 1 (0-3, 73.8%, 0.34%), group 2 (4-6, 17.6%, 5.8%), group 3 (7-9, 8.7%, 12.8%) with a C-statistic 0.85 (95% CI 0.78-0.91). In comparison the prevalence (primary outcome) by Bova risk stages (n=1179) were stage I 49.8% (0.2%); stage II 31.9% (2.7%); and stage III 18.4% (7.8%) with a C-statistic 0.80 (95% CI 0.74-0.86). CONCLUSIONS: A simple four-variable risk score using clinical data immediately available after CT diagnosis of acute PE predicts in-hospital adverse outcomes. External validation of the Calgary Acute Pulmonary Embolism score is required.

Which Patients Should Have Early Surgical Intervention for Acute Ureteral Colic?

PURPOSE: Early surgical intervention is an attractive option for acute ureteral colic but existing evidence does not clarify which patients benefit. We compared treatment failure rates in patients receiving early intervention and patients offered spontaneous passage to identify subgroups that benefit from early intervention. MATERIALS AND METHODS: We used administrative data and structured chart review to study consecutive patients attending 9 emergency departments in 2 Canadian provinces with confirmed 2.0 to 9.9 mm ureteral stones. We described patient, stone and treatment characteristics, and performed multivariable regression to identify factors associated with treatment failure, defined as intervention or hospitalization within 60 days. Our secondary outcome was emergency department revisit rate. RESULTS: Overall 1,168 of 3,081 patients underwent early intervention. Those with stones smaller than 5 mm experienced more treatment failures (31.5% vs 9.9%, difference 21.6%, 95% CI 16.9 to 21.2) and emergency department revisits (38.5% vs 19.7%, difference 18.8%, 95% CI 13.8 to 23.8) with early intervention than with spontaneous passage. Patients with stones 7.0 mm or larger experienced fewer treatment failures (34.7% vs 58.6%, risk difference 23.9%, 95% CI 11.3 to 36.6) and similar emergency department revisit rates with early intervention. Patients with 5.0 to 6.9 mm stones had fewer treatment failures with intervention (37.4% vs 55.5%, risk difference 18.1%, 95% CI 7.1 to 28.9) if stones were in the proximal or middle ureter. CONCLUSIONS: Early intervention improves outcomes for patients with large (greater than 7 mm) ureteral stones or 5 to 7 mm proximal or mid ureteral stones. Early intervention may increase morbidity for patients with stones smaller than 5 mm. These findings could help inform future guidelines.

Prospective comparative evaluation of the European Society of Cardiology (ESC) 1-hour and a 2-hour rapid diagnostic algorithm for myocardial infarction using high-sensitivity troponin-T.

OBJECTIVE: Both 1- and 2-hour rapid diagnostic algorithms using high-sensitivity troponin (hs-cTn) have been validated to diagnose acute myocardial infarction (MI), leaving physicians uncertain which algorithm is preferable. The objective of this study was to prospectively evaluate the diagnostic performance of 1- and 2-hour algorithms in clinical practice in a Canadian emergency department (ED). METHODS: ED patients with chest pain had high-sensitivity cardiac troponin-T (hs-cTnT) collected on presentation and 1- and 2-hours later at a single academic centre over a 2-year period. The primary outcome was index MI, and the secondary outcome was 30-day major adverse cardiac events (MACE). All outcomes were adjudicated. RESULTS: We enrolled 608 patients undergoing serial hs-cTnT sampling. Of these, 350 had a valid 1-hour and 550 had a 2-hour hs-cTnT sample. Index MI and 30-day MACE prevalence was ~12% and 14%. Sensitivity of the 1- and 2-hour algorithms was similar for index MI 97.3% (95% CI: 85.8-99.9%) and 100% (95% CI: 91.6-100%) and 30-day MACE: 80.9% (95% CI: 66.7-90.9%) and 83.3% (95% CI: 73.2-90.8%), respectively. Both algorithms accurately identified about 10% of patients as high risk. CONCLUSIONS: Both algorithms were able to classify almost two-thirds of patients as low risk, effectively ruling out MI and conferring a low risk of 30-day MACE for this group, while reliably identifying high-risk patients. While both algorithms had equivalent diagnostic performance, the 2-hour algorithm offers several practical advantages, which may make it preferable to implement. Broad implementation of similar algorithms across Canada can expedite patient disposition and lead to resource savings.

Low High-Sensitivity Troponin Thresholds Identify Low-Risk Patients With Chest Pain Unlikely to Benefit From Further Risk Stratification.

BACKGROUND: Very low high-sensitivity cardiac troponin T (hs-cTnT) thresholds on presentation can rule out acute myocardial infarction (AMI), but the ability to identify patients at low risk of 30-day major adverse cardiac events (MACE) is less clear. This study examines the sensitivity of low concentrations of hs-cTnT on presentation to rule out 30-day MACE. METHODS: This prospective cohort study enrolled patients with chest pain presenting to the emergency department with nonischemic electrocardiograms who underwent AMI rule-out with an hs-cTnT assay. The primary outcome was 30-day MACE; secondary outcomes were individual MACE components. Because guidelines recommend using a single hs-cTnT strategy only for patients with more than 3 hours since symptom onset, a subgroup analysis was performed for this population. Outcomes were adjudicated on the basis of review of medical records and telephone follow-up. RESULTS: Of 1167 patients enrolled, 125 (10.7%) experienced 30-day MACE and 97 (8.3%) had AMI on the index visit. More than one-third of patients (35.6%) had presenting hs-cTnT concentrations below the limit of detection (5 ng/L), which was 94.4% (95% confidence interval [CI], 88.8-97.7) sensitive for 30-day MACE and 99.0% (95% CI, 94.5-100) sensitive for index AMI. Of 292 patients (25.0%) with hs-cTnT < 5 ng/L and at least 3 hours since symptom onset, only 3 experienced 30-day MACE (sensitivity 97.6%; 95% CI, 93.2-100) and none had AMI within 30 days (sensitivity 100%; 95% CI, 96.3-100). CONCLUSIONS: Among patients with nonischemic electrocardiograms and > 3 hours since symptom onset, low hs-cTnT thresholds on presentation confer a very low risk of 30-day MACE. In the absence of a high-risk clinical presentation, further risk stratification is likely to be low yield.

CONTEXTE: Un seuil de troponine T cardiaque hypersensible (TnTc-hs) très bas au moment de la consultation permet d'écarter le diagnostic d'infarctus aigu du myocarde (IAM), mais l'utilité de ce paramètre pour reconnaître les patients exposés à un faible risque d'événement cardiaque indésirable majeur (ECIM) à 30 jours est moins bien établie. Les auteurs examinent la sensibilité de la présence d'une faible concentration de TnTc-hs à la consultation comme critère pour écarter la possibilité d'un ECIM à 30 jours. MÉTHODE: Ont été admis dans cette étude de cohorte prospective les patients qui se sont présentés à l'urgence en raison d'une douleur à la poitrine, dont l'électrocardiogramme n'a pas révélé d'ischémie et chez qui le diagnostic d'IAM a été écarté au moyen d'un dosage de la TnTc-hs. Le critère d'évaluation principal était la survenue d'un ECIM à 30 jours; les critères d'évaluation secondaires étaient les composantes individuelles de l'ECIM. Comme les lignes directrices recommandent le recours à un simple dosage de la TnTc-hs seulement pour les patients présentant des symptômes depuis plus de 3 heures, une analyse a été réalisée dans ce sous-groupe de la population à l'étude. Les critères d'évaluation ont été confirmés par un examen des dossiers médicaux et par un suivi téléphonique. RÉSULTATS: Des 1167 patients retenus, 125 (10,7 %) ont présenté un ECIM à 30 jours et 97 (8,3 %) avaient reçu un diagnostic d'IAM à la visite de référence. Au moment de la consultation, plus du tiers des patients (35,6 %) présentaient une concentration de TnTc-hs sous le seuil de détection (5 ng/l), ce qui représente une sensibilité de 94,4 % (intervalle de confiance [IC] à 95 % : de 88,8 à 97,7) dans le cas de l'ECIM à 30 jours et de 99,0 % (IC à 95 % : de 94,5 à 100) dans le cas de l'IAM de référence. Des 292 patients (25,0 %) présentant un taux de TnTc-hs < 5 ng/l et des symptômes apparus depuis au moins 3 heures, seulement 3 ont subi un ECIM à 30 jours (sensibilité de 97,6 %; IC à 95 % : de 93,2 à 100) et aucun n'a subi d'IAM dans les 30 jours (sensibilité de 100 %; IC à 95 % : de 96,3 à 100). CONCLUSIONS: Chez les patients dont l'électrocardiogramme ne révèle pas d'ischémie et qui présentent des symptômes depuis au moins 3 heures, un seuil de TnTc-hs faible au moment de la consultation est associé à un très faible risque d'ECIM à 30 jours. En l'absence d'un tableau clinique associé à un risque élevé, il est peu probable qu'une stratification du risque plus poussée soit utile.

Sex-specific, high-sensitivity cardiac troponin T cut-off concentrations for ruling out acute myocardial infarction with a single measurement.

OBJECTIVE: Sex-specific diagnostic cut-offs may improve the test characteristics of high-sensitivity troponin assays for the diagnosis of myocardial infarction (MI). The objective of this study was to quantify test characteristics of sex-specific cut-offs of a single, high-sensitivity cardiac troponin T (hs-cTnT) assay for 7-day MI in patients with chest pain. METHODS: This observational cohort study included consecutive emergency department (ED) patients with suspected cardiac chest pain from four Canadian EDs who had an hs-cTnT assay performed within 60 minutes of ED arrival. The primary outcome was MI at 7 days. We quantified test characteristics (sensitivity, negative predictive value [NPV], likelihood ratios and proportion of patients ruled out) for multiple combinations of sex-specific, rule-out cut-offs. We calculated the net reclassification index compared to universal rule-out cut-offs. RESULTS: In 7,130 patients (3,931 men and 3,199 women), the 7-day MI incidence was 7.38% among men and 3.78% among women. Optimal sex-specific cut-offs (<8 ng/L for men and <7 ng/L for women) had a 98.5% sensitivity for MI and ruled out MI in 55.8% of patients. This would enable an absolute increase in the proportion of patients who were able to be ruled out with a single hs-cTnT of 13.2% to 22.2%, depending on the universal rule-out concentration used as a comparator. CONCLUSIONS: Sex-specific hs-cTnT cut-offs for ruling out MI at ED arrival may improve classification performance, enabling more patients to be safely ruled out at ED arrival. However, differences between sex-specific and universal cut-off concentrations are within the variation of the assay, limiting the clinical utility of this approach. These findings should be confirmed in other data sets.

Age-adjusted D-dimer thresholds in the investigation of suspected pulmonary embolism: A retrospective evaluation in patients ages 50 and older using administrative data.

OBJECTIVES: D-dimer testing is an important component of the workup for pulmonary embolism (PE). However, age-related increases in D-dimer concentrations result in false positives in older adults, leading to potentially unnecessary imaging utilization. The objective of this study was to quantify the test characteristics of an age-adjusted D-dimer cut-off for ruling out PE in older patients investigated in actual clinical practice. METHODS: This observational study used administrative data from four emergency departments from July 2013 to January 2015. Eligible patients were ages 50 and older with symptoms of PE who underwent D-dimer testing. The primary outcome was 30-day diagnosis of PE, confirmed by imaging reports. Test characteristics of the D-dimer assay were calculated using the standard reference value (500 ng/ml), the local reference value (470 ng/ml), and an age-adjusted threshold (10 ng/ml × patient's age). RESULTS: This cohort includes 6,655 patients ages 50 and older undergoing D-dimer testing for a possible PE. Of these, 246 (3.7%) were diagnosed with PE. Age-adjusted D-dimer cut-offs were more specific than standard cut-offs (75.4% v. 63.8%) but less sensitive (90.3% v. 97.2%). The false-negative risk in this population was 0.49% using age-adjusted D-dimer cut-offs compared with 0.15% with traditional cut-offs. CONCLUSION: Age-adjusted D-dimer cut-offs are substantially more specific than traditional cut-offs and may reduce CT utilization among older patients with suspected PE. We observed a loss of sensitivity, with an increased risk of false-negatives, using age-adjusted cut-offs. We encourage further evaluation of the safety and accuracy of age-adjusted D-dimer cut-offs in actual clinical practice.

Profile of Roche's Elecsys Troponin T Gen 5 STAT blood test (a high-sensitivity cardiac troponin assay) for diagnosing myocardial infarction in the emergency department.

INTRODUCTION: The Elecsys Troponin T Gen 5 STAT test (distributed in the United States (US) by Roche Diagnostics, Indianapolis, IN) is the first high-sensitivity cardiac troponin test approved for use by the FDA in the US (2017). Areas covered: The test offers clinicians the opportunity for more rapid decision-making for diagnosing myocardial infarction (MI) in the emergency department (ED). The Troponin T Gen 5 STAT test (labeled as TNT-G5ST on the reagent pack) is similar to the Troponin T hs STAT (TNT-HSST) and Troponin T hs (TNT-HS) tests that have been available outside the US since 2009. Collectively, these tests can all be considered as high-sensitivity cardiac troponin T (hs-cTnT) assays. Expert commentary: Studies performed in the US and throughout the world using 0 and 3 h blood draws for hs-cTnT testing in patients with possible MI have reliably achieved a sensitivity of >94% and negative predictive value of ≥99% for MI in the ED setting.

Variability of renal colic management and outcomes in two Canadian cities.

BACKGROUND: Some centres favour early intervention for ureteral colic while others prefer trial of spontaneous passage, and relative outcomes are poorly described. Calgary and Vancouver have similar populations and physician expertise, but differing approaches to ureteral colic. We studied 60-day hospitalization and intervention rates for patients having a first emergency department (ED) visit for ureteral colic in these diverse systems. METHODS: We used administrative data and structured chart review to study all Vancouver and Calgary patients with an index visit for ureteral colic during 2014. Patient demographics, arrival characteristics and triage category were captured from ED information systems, while ED visits and admissions were captured from linked regional hospital databases. Laboratory results were obtained from electronic health records and stone characteristics were abstracted from diagnostic imaging reports. Our primary outcome was hospitalization or urological intervention from 0 to 60 days. Secondary outcomes included ED revisits, readmissions and rescue interventions. Time to event analysis was conducted and Cox Proportional Hazards modelling was performed to adjust for covariate imbalance. RESULTS: We studied 3283 patients with CT-defined stones. Patient and stone characteristics were similar for the cities. Hospitalization or intervention occurred in 60.9% of Calgary patients and 31.3% of Vancouver patients (p<0.001). Calgary patients had higher index intervention rates (52.1% v. 7.5%), and experienced more ED revisits and hospital readmissions during follow-up. The data suggest that outcome events were associated with overtreatment of small stones in one city and undertreatment of large stones in the other. CONCLUSIONS: An early interventional approach was associated with higher ED revisit, hospitalization and intervention rates. If these events are markers of patient disability, then a less interventional approach to small stones and earlier definitive management of large stones may reduce system utilization and improve outcomes for patients with acute ureteral colic.

Contemporary Emergency Department Management of Patients with Chest Pain: A Concise Review and Guide for the High-Sensitivity Troponin Era.

This article synthesizes current best evidence for the evaluation of patients with suspected acute coronary syndrome (ACS) using high-sensitivity troponin assays, enabling physicians to effectively incorporate them into practice. Unlike conventional assays, high-sensitivity assays can precisely measure blood cardiac troponin concentrations in the vast majority of healthy individuals, facilitating the creation of rapid diagnostic algorithms. Very low troponin concentrations on presentation accurately rule out acute myocardial infarction (AMI) and enable the discharge of approximately 20% of patients after a single test, whereas an additional 30%-40% of patients can be safely discharged after short-interval serial sampling in as little as 1 or 2 hours. In contrast, highly abnormal troponin concentrations on presentation (more than 5 times the upper reference limit) or rapidly rising levels on serial testing can rapidly rule in AMI with high specificity. However, approximately one-third of patients remain in a biomarker-indeterminate "observation zone" even after serial sampling. These patients pose a disposition challenge to clinicians because although the differential diagnosis of elevated troponin concentrations is broad, these patients have an increased risk for short-term major adverse cardiac events. Use of repeated serial troponin sampling and structured clinical prediction tools may assist disposition for these patients, because no validated pathways currently exist to guide clinicians. Ongoing research to tailor diagnostic thresholds to individual patient characteristics may enable improved diagnostic accuracy and usher in a new era of personalized medicine in the evaluation of suspected ACS.

Comparative Evaluation of 2-Hour Rapid Diagnostic Algorithms for Acute Myocardial Infarction Using High-Sensitivity Cardiac Troponin T.

BACKGROUND: Symptoms of acute coronary syndrome account for a large proportion of emergency department (ED) visits and hospitalizations. High-sensitivity troponin can rapidly rule out or rule in acute myocardial infarction (AMI) within a short time of ED arrival. We sought to validate test characteristics and classification performance of 2-hour high-sensitivity troponin T (hsTnT) algorithms for the rapid diagnosis of AMI. METHODS: We included consecutive patients from 4 academic EDs with suspected cardiac chest pain who had hsTnT assays performed 2 hours apart (± 30 minutes) as part of routine care. The primary outcome was AMI at 7 days. Secondary outcomes included major adverse cardiac events (mortality, AMI, and revascularization). Test characteristics and classification performance for multiple 2-hour algorithms were quantified. RESULTS: Seven hundred twenty-two patients met inclusion criteria. Seven-day AMI incidence was 10.9% and major adverse cardiac event incidence was 13.7%. A 2-hour rule-out algorithm proposed by Reichlin and colleagues ruled out AMI in 59.4% of patients with 98.7% sensitivity and 99.8% negative predictive value (NPV). The 2-hour rule-out algorithm proposed by the United Kingdom National Institute for Health and Care Excellence ruled out AMI in 50.3% of patients with similar sensitivity and NPV. Other exploratory algorithms had similar sensitivity but marginally better classification performance. According to Reichlin et al., the 2-hour rule-in algorithm ruled in AMI in 16.5% of patients with 92.4% specificity and 58.5% positive predictive value. CONCLUSIONS: Two-hour hsTnT algorithms can rule out AMI with very high sensitivity and NPV. The algorithm developed by Reichlin et al. had superior classification performance. Reichlin and colleagues' 2-hour rule-in algorithm had poor positive predictive value and might not be suitable for early rule-in decision-making.

Undetectable Concentrations of a Food and Drug Administration-approved High-sensitivity Cardiac Troponin T Assay to Rule Out Acute Myocardial Infarction at Emergency Department Arrival.

BACKGROUND: The objective of this study was to quantify the sensitivity of very low concentrations of high-sensitivity cardiac troponin T (hsTnT) at ED arrival for acute myocardial infarction (AMI) in a large cohort of chest pain patients evaluated in real-world clinical practice. METHODS: This retrospective study included consecutive ED patients with suspected cardiac chest pain evaluated in four urban EDs, excluding those with ST-elevation AMI, cardiac arrest or abnormal kidney function. The primary outcomes were AMI at 7, 30, and 90 days. Secondary outcomes included major adverse cardiac events (MACE; all-cause mortality, AMI, and revascularization) and the individual MACE components. Test characteristics were calculated for hsTnT values from 3 to 200 ng/L . RESULTS: A total of 7,130 patients met inclusion criteria. AMI incidences at 7, 30, and 90 days were 5.8, 6.0, and 6.2%. When the hsTnT assay was performed at ED arrival, the limit of blank of the assay (3 ng/L) ruled out 7-day AMI in 15.5% of patients with 100% sensitivity and negative predictive value (NPV). The limit of detection of the assay (5 ng/L) ruled out AMI in 33.6% of patients with 99.8% sensitivity and 99.95% NPV for 7-day AMI. The limit of quantification (the Food and Drug Administration [FDA]-approved cutoff for lower the reportable limit) of 6 ng/L ruled out AMI in 42.2% of patients with 99.8% sensitivity and 99.95% NPV. The sensitivities of the cutoffs of <3, <5, and <6 ng/L for 7-day MACE were 99.6, 97.4, and 96.6%, respectively. The NPVs of the cutoffs of <3, <5, and <6 ng/L for 7-day MACE were 99.8, 99.5, and 99.4%, respectively. A secondary analysis was performed in a subgroup of 3,549 higher-risk patients who underwent serial troponin testing. In this subgroup, a cutoff of 3 ng/L ruled out 7-day AMI in 9.6% of patients with 100% sensitivity and NPV, a cutoff of 5 ng/L ruled out 7-day AMI in 23.3% of patients with 99.7% sensitivity and 99.9% NPV, and a cutoff of 6 ng/L ruled out 7-day AMI in 29.8% of patients with 99.7 and 99.9% NPV. In the higher-risk subgroup, the sensitivities of cutoffs of <3, <5, and <6 ng/L for 7-day MACE were 99.8, 97.4, and 96.6%, respectively. In this higher-risk subgroup, the NPV of cutoffs of <3, <5, and <6 ng/L for 7-day MACE were 99.7, 98.5, and 98.4%, respectively. CONCLUSIONS: When used in real-world clinical practice conditions, hsTnT concentrations < 6 ng/L (below the lower reportable limit for an FDA-approved assay) at the time of ED arrival can rule out AMI with very high sensitivity and NPV. The sensitivity for MACE is unacceptably low, and thus a single-troponin rule-out strategy should only be used in the context of a structured risk evaluation.

Impact of Clinical Decision Support on Radiography for Acute Ankle Injuries: A Randomized Trial.

INTRODUCTION: While only 15-20% of patients with foot and ankle injuries presenting to urgent care centers have clinically significant fractures, most undergo radiography. We examined the impact of electronic point-of-care clinical decision support (CDS) on adherence to the Ottawa Ankle Rules (OAR), as well as use and yield of foot and ankle radiographs in patients with acute ankle injury. METHODS: We obtained institutional review board approval for this randomized controlled study performed April 18, 2012-December 15, 2013. All ordering providers credentialed at an urgent care affiliated with a quaternary care academic hospital were randomized to either receive or not receive CDS, based on the OAR and integrated into the physician order-entry system, with feedback at the time of imaging order. If the patient met OAR low-risk criteria, providers were advised against imaging and could either cancel the order or ignore the alert. We identified patients with foot and ankle complaints via ICD-9 billing codes and electronic health records and radiology reports reviewed for those who were eligible. Chi-square was used to compare adherence to the OAR (primary outcome), radiography utilization rate and radiography yield of foot and ankle imaging (secondary outcomes) between the intervention and control groups. RESULTS: Of 14,642 patients seen at urgent care during the study period, 613 (4.2%, representing 632 visits) presented with acute ankle injury and were eligible for application of the OAR; 374 (59.2%) of these were seen by control-group providers. In the intervention group, CDS adherence was higher for both ankle (239/258=92.6% vs. 231/374=61.8%, p=0.02) and foot radiography (209/258=81.0% vs. 238/374=63.6%; p<0.01). However, ankle radiography use was higher in the intervention group (166/258=64.3% vs. 183/374=48.9%; p<0.01), while foot radiography use (141/258=54.6% vs. 202/374=54.0%; p=0.95) was not. Radiography yield was also higher in the intervention group (26/307=8.5% vs. 18/385=4.7%; p=0.04). CONCLUSION: Clinical decision support, previously demonstrated to improve guideline adherence for high-cost imaging, can also improve guideline adherence for radiography - as demonstrated by increased OAR adherence and increased imaging yield.