The Canadian Syncope Risk Score to Identify Patients at Risk for SAE after ED Disposition

Transcription

1 The Canadian Syncope Risk Score to Identify Patients at Risk for SAE after ED Disposition CAEP Edmonton May 2015

2 Venkatesh Thiruganasambandamoorthy MBBS Kenneth Kwong BSc Marco Sivilotti MD Brian Rowe MD George Wells PhD Robert Sheldon MD Eddy Lang MD Muhammad Mukarram MBBS Andrew McRae MD Monica Taljaard PhD Ian Stiell MD Department of Emergency Medicine Ottawa Hospital Research Institute University of Ottawa, Ottawa, ON Funded by the Physicians Incorporated Foundation, Ontario Innovation Fund and Canadian Institutes of Health Research No Financial COI to Disclose

3 Syncope: The Clinical Problem 1% of all ED visits 7 23% suffer serious adverse events (SAE) with 50% occurring after ED disposition Risk stratification is challenging Previous attempts to develop a robust tool unsuccessful Small, retrospective, no statistical methods Methodological flaws

4 Prior Work Validation of the San Francisco Syncope Rule (N=505) Ann Emerg Med 2010 Canadian Cardiovascular Society Position Paper Can J Cardio 2011 Standardized Reporting Guidelines Acad Emerg Med 2012 Risk Factors for Serious Outcomes (N=505) CJEM 2013 Need for Standardization and Risk Stratification (N=3,662) Intern Emerg Med 2015 Outcomes among Non Sinus Rhythm Patients (N=4,335) Int J Cardiol 2015

5 Objective Derive a clinical decision tool for identification of patients at risk for serious adverse events within 30 days after ED disposition

6 Methods Design: Prospective cohort study Setting: 6 Canadian academic EDs Study Period: 41 months (Oct 2010 to Feb 2014) Subjects: Adult ( 16 years) with syncope who presented to ED within 24 hours Exclusions: Previously enrolled, prolonged LOC (> 5 min), mental status changes, obvious witnessed seizure, significant trauma, intoxicated alcohol/illicit drug, or language barrier Ethics: Only verbal consent was required for inclusion into the study

7 Methods Study Protocol Training sessions Consecutive patients screened and enrolled Data collection: 37 variables (18 categorical and 19 continuous) Categorical Variables: Sex 6event characteristics, 2 medical history (vascular disease 3 variables, heart disease 5 variables), 2 family history Final ED diagnosis (vasovagal, cardiac, others) at disposition Lab test: Troponin >99 th percentile 4ECG: Blocks, axis deviation, ventricular hypertrophy, old ischemia

8 Methods Study Protocol 19 Continuous Variables: Age 11 ED vitals: 6 BPs, 3 pulse rates, triage respiratory rate and O2 saturation 4 Lab tests: Hemoglobin, hematocrit, BUN, and creatinine 3 ECG: QRS axis, QRS duration and cqt interval

9 Methods Outcome Measures: Death, MI, arrhythmias, structural heart disease, aortic dissection, pulmonary embolism, severe pulmonary HTN, SAH, significant hemorrhage, or any serious condition that requires intervention Outcome Assessment: Review of medical records Telephone follow up Review of records in local hospitals All SAE confirmed by an independent blinded Adjudication Committee of 3 physicians

10 Methods Data Analysis Excluded those with SAE in the ED Variables excluded: Fewer than 5 events >25% missing values Kappa <0.4 Univariate analysis Multiple imputation for missing variables Cut points using clinical rationale and ROC curve Multivariable logistic regression Internal validation

11 Patient Flow Visits Screened N=11,998 Potentially Eligible Syncope Visits N=6,158 Not Syncope = 4,357 Prolonged LOC = 340 Seizure = 253 Change in Mental Status = 142 Head Trauma = 167 Alcohol/Drug Related = 113 Significant Trauma = 72 Language Barrier = 76 LWBS = 165 Patients Included N=4,326 Double Enrollments = 129 Refused = 155 Not Enrolled = 1,263 Serious Outcome in the ED = 285 Lost to Follow Up = 292 (6.7%) Included in Final Analysis N=4,034 (93.2%) Patient with Serious Outcomes N=147 (3.6%)

12 Patient Characteristics (N=4,034) Mean Age in Years 53.6 (23.0) Range 16 to 102 Female (%) 55.6 Arrival by Ambulance (%) 64.3 ED Investigations Performed (%) ECG 95.1 Blood Tests 85.5 Disposition (%) ED Referral for Consultations 17.5 Hospitalizations 9.5

13 Serious Outcomes 30 Day SAE (N=4,034) Total N=147 Inpatient N=86 Outside Hospital N=61 Total Deaths Deaths Cause Unknown Cardiac New/Uncontrolled Afib or SVT Sinus Node Dysfunction High Grade AV Block ACS Ventricular Arrhythmia Device Insertion/Malfunction Structural HD or Dissection Significant Hemorrhage Pulmonary Embolism Others*

14 Variables for Logistic Regression Low Events: FHx congenital HD and sudden death All blocks except LBBB Axis deviations (RAD, LAD) Not significant: 4 event variables: witnessed, palpitations prior, activity or orthostatic symptoms Old ischemia Triage DBP, triage HR, lowest HR Low prevalence at abnormal values: Triage O2 saturation Hemoglobin 22 predictor variables were selected for logistic regression

15 Predictors for Logistic Regression Variable SAE N=147 No SAE N=3,887 P Value Age > 75 Years < Female Vascular Disease Heart Disease < Valvular Heart Disease < Cardiomyopathy < Congestive Heart Failure < Coronary Artery Disease < Non Sinus Rhythm < Vasovagal Predisposition <0.0001

16 Predictors for Logistic Regression Variable SAE N=147 No SAE N=3,887 P Value Prodrome < Any SBP <90 or >180mmHg < Lowest ED DBP <50mmHg < Highest ED DBP >110mmHg < Highest ED Heart Rate>110/min Triage Respiratory Rate >20/min Troponin >99 th Percentile < Hematocrit < Urea >12mmol/L < Creatinine >150µmol/L

17 Predictors for Logistic Regression Variable SAE N=147 No SAE N=3,887 P Value Left Bundle Branch Block < Left Ventricular Hypertrophy QRS Duration >130 msec < Abnormal Axis (< 30 or >110) < cqt Interval >480 msec < ED Diagnosis Vasovagal Syncope < Cardiac Syncope <0.0001

18 Independent Predictors of SAEs from Logistic Regression (N=4,034) Variable OR (95% CI) Beta Vasovagal Predisposition 0.5 ( ) 0.6 Heart Disease 1.7 ( ) 0.5 ED SBP <90 or >180 mmhg 2.3 ( ) 0.8 ED Diagnosis Vasovagal Syncope 0.4 ( ) 1.0 ED Diagnosis Cardiac Syncope 3.6 ( ) 1.3 Troponin >99 th Percentile 3.5 ( ) 1.2 Abnormal QRS Axis (< 30; >110) 1.7 ( ) 0.6 QRS Duration > 130 msec 1.9 ( ) 0.6 cqt Interval >480 msec 2.9 ( ) 1.1 Hosmer Lemeshow Goodness of fit p value = 0.12 Area under ROC curve (optimism corrected)= 0.86 (95% CI 0.83, 0.89)

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21 Internal Validation Boot Strapping

22 Classification Performance of the CSRS Score Sensitivity Specificity Quick Disposition 2 99% 26% 44.3% 1 98% 46% 54.7% Potential Admissions 3 65% 91% 10.9% 4 51% 95% 6.4%

23 Summary The Canadian Syncope Risk Score has the potential to: Standardize ED management of syncope patients Accurately risk stratification for evidence based disposition decision making Reduce the proportion of patients suffering SAE outside the hospital Reduce admissions in some centers Identify patients for observation units and hospitalization

24 Limitations One fifth of eligible patients were not enrolled Half of the patients did not have troponin levels measured A small proportion of patients lost to follow up ED diagnosis part of the model Needs to be prospectively validated before application into clinical practice

25 Conclusion Once prospectively validated the Canadian Syncope Risk Scale has the potential to improve acute management of syncope patients

26 Acknowledgements Physicians for completion of the data forms Clerks and Nurses who ensure compliance Research teams at the study sites Drs. Hina Chaudry and Roos Ramaekers RNs: Pam Ladouceur, Sarah Gaudet and Karen Pratt Laura Baker, Natacha Leduc, Marco Guarino, Cynthia Campbell, Alex Viau, Brittany Mutsaers and Tauralee Tenn Angela Marcantonio and Cathy Clement Soo Min Kim

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28 Groups With and Without Troponin

29 Variable Variables Excluded SAE N=147 No SAE N=3,887 P Value Event Witnessed Palpitations Prior Activity High Risk Orthostatic Symptoms Old Ischemia

30 Variable SAE N=147 No SAE N=3,887 P Value Triage DBP (mmhg) Triage Heart Rate Lowest Heart Rate Variable Variables Excluded SAE N=147 No SAE N=3,887 P Value Triage O2 Saturation (%) < Hemoglobin (g/l) predictor variables were selected for logistic regression

31 Predictors for Logistic Regression Variable SAE N=147 No SAE N=3,887 P Value Age in Years < Age > 75 Years < Females Vascular Disease Heart Disease < Valvular Heart Disease < Cardiomyopathy < Congestive Heart Failure < Coronary Artery Disease < Non Sinus Rhythm <0.0001

32 Predictors for Logistic Regression Variable SAE N=147 No SAE N=3,887 P Value Vasovagal Predisposition < Prodrome < Triage SBP (mmhg) Highest SBP in ED < Any SBP <90 or >180mmHg < Lowest ED DBP Lowest ED DBP <50mmHg < Highest ED DBP Highest ED DBP >110mmHg <0.0001

33 Predictors for Logistic Regression Variable SAE No SAE P Value N=147 N=3,887 Highest ED Heart Rate Highest ED Heart Rate>110/min Triage RespiratoryRate Triage Respiratory Rate >20/min Troponin >99 th Percentile < Hematocrit Hematocrit < Urea < Urea >12mmol/L < Creatinine Creatinine >150µmol/L

34 Predictors for Logistic Regression Variable SAE N=147 No SAE N=3,887 P Value Left Bundle Branch Block < Left Ventricular Hypertrophy Mean QRS Duration < QRS Duration >130 msec < Mean QRS Axis Abnormal Axis (< 30 or >110) < Mean cqt Interval < cqt Interval >480 msec < ED Diagnosis Vasovagal Syncope < Cardiac Syncope <0.0001

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