Download The Canadian Syncope Risk Score to Identify Patients at Risk for

The Canadian Syncope Risk Score to Identify Patients at Risk for SAE after ED Disposition
CAEP Edmonton May 2015
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
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
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
Objective
Derive a clinical decision tool for identification of patients at‐risk for serious adverse events within 30‐days after ED disposition
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
Methods – Study Protocol
Training sessions Consecutive patients screened and enrolled
Data collection: 37 variables (18 categorical and 19 continuous)
Categorical Variables: Sex
6 event 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 >99th percentile
4 ECG: Blocks, axis deviation, ventricular hypertrophy, old ischemia
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
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 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
Patient Flow Visits Screened
N=11,998
Potentially Eligible Syncope Visits
N=6,158
Patients Included
N=4,326
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
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%)
Patient Characteristics (N=4,034)
Mean Age in Years
Range Female (%)
Arrival by Ambulance (%)
53.6 (23.0)
16 to 102
55.6
64.3
ED Investigations Performed (%)
ECG
95.1
Blood Tests
85.5
Disposition (%)
ED Referral for Consultations
Hospitalizations
17.5
9.5
30‐Day SAE (N=4,034)
Serious Outcomes
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*
Total
N=147
Inpatient
N=86
21
14
98
9
18
9
11
15
24
12
10
8
17
8
3
65
1
10
6
6
11
21
10
6
6
6
Outside
Hospital
N=61
13
11
33
8
8
3
5
4
3
2
4
2
11
Variables for Logistic Regression
Low Events:
Not significant: FHx congenital HD and sudden death
4 event variables: witnessed, palpitations prior, activity or orthostatic symptoms
All blocks except LBBB
Old ischemia
Axis deviations (RAD, LAD)
Triage DBP, triage HR, lowest HR
Low prevalence at abnormal values: Triage O2 saturation
Hemoglobin
22 predictor variables were selected for logistic regression
Predictors for Logistic Regression
Variable
Age > 75 Years
Female
Vascular Disease
Heart Disease
Valvular Heart Disease
Cardiomyopathy
Congestive Heart Failure
Coronary Artery Disease
Non‐Sinus Rhythm
Vasovagal Predisposition
SAE
No SAE P‐Value
N=147 N=3,887
49.0
22.4 <0.0001
42.9
56.0
0.0016
10.9
6.3
0.02
56.5
19.3 <0.0001
15.7
2.9 <0.0001
8.8
0.9 <0.0001
15.0
3.3 <0.0001
31.3
11.1 <0.0001
30.7
9.2 <0.0001
12.9
42.9 <0.0001
Predictors for Logistic Regression
Variable
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 >99th Percentile
Hematocrit <0.3
Urea >12mmol/L
Creatinine >150µmol/L
SAE No SAE P‐Value
N=147 N=3,887
56.9
31.3
20.6
8.2
12.2
10.1
25.2
9.0
15.7
11.7
76.1
11.6
9.1
2.4
6.4
3.5
3.4
3.5
5.6
5.4
<0.0001
<0.0001
<0.0001
<0.0001
0.0047
0.0002
<0.0001
0.0007
<0.0001
0.0012
Predictors for Logistic Regression Variable
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
SAE
No SAE P‐Value
N=147 N=3,887
11.4
2.3 <0.0001
9.9
5.5
0.03
31.6
5.1 <0.0001
32.3
8.3 <0.0001
38.4
6.4 <0.0001
13.2
35.4
55.7 <0.0001
5.0 <0.0001
Independent Predictors of SAEs from Logistic Regression (N=4,034)
Variable
Vasovagal Predisposition
Heart Disease
ED SBP <90 or >180 mmHg ED Diagnosis Vasovagal Syncope
ED Diagnosis Cardiac Syncope
Troponin >99th Percentile
Abnormal QRS Axis (<‐30; >110)
QRS Duration > 130 msec
cQT Interval >480 msec
OR (95% CI)
0.5 (0.3‐0.9)
1.7 (1.2‐2.5)
2.3 (1.5‐3.4)
0.4 (0.2‐0.7)
3.6 (2.3‐5.5)
3.5 (2.1‐5.6)
1.7 (1.1‐2.8)
1.9 (1.1‐3.2)
2.9 (1.8‐4.5)
Beta
‐0.6
0.5
0.8
‐1.0
1.3
1.2
0.6
0.6
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)
Internal Validation ‐ Boot Strapping 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%
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
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
Conclusion
Once prospectively validated the Canadian Syncope Risk Scale has the potential to improve acute management of syncope patients
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
Groups With and Without Troponin Variables Excluded
Variable
SAE
N=147
No SAE
N=3,887
P‐Value
Event Witnessed
68.3
71.1
0.46
Palpitations Prior
3.5
5.6
0.29
Activity High‐Risk
43.8
39.4
0.29
Orthostatic Symptoms
18.9
21.2
0.51
Old Ischemia
6.8
4.6
0.23
Variables Excluded
Variable
SAE
N=147
No SAE
N=3,887
P‐Value
Triage DBP (mmHg)
74.2 73.7
0.71
Triage Heart Rate 79.1
77.4
0.38
Lowest Heart Rate
67.9
69.9
0.17
Variable
SAE
N=147
No SAE
N=3,887
P‐Value
Triage O2 Saturation (%)
94.4
96.6
<0.0001
Hemoglobin (g/L)
127.9
134.8
0.0002
22 predictor variables were selected for logistic regression
Predictors for Logistic Regression
Variable
Age in Years
Age > 75 Years
Females
Vascular Disease
Heart Disease
Valvular Heart Disease
Cardiomyopathy
Congestive Heart Failure
Coronary Artery Disease
Non‐Sinus Rhythm
SAE
No SAE P‐Value
N=147 N=3,887
71.6
52.9 <0.0001
49.0
22.4 <0.0001
42.9
56.0
0.0016
10.9
6.3
0.02
56.5
19.3 <0.0001
15.7
2.9 <0.0001
8.8
0.9 <0.0001
15.0
3.3 <0.0001
31.3
11.1 <0.0001
30.7
9.2 <0.0001
Predictors for Logistic Regression
Variable
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
SAE
No SAE P‐Value
N=147 N=3,887
12.9
56.9
133.3
149.1
31.3
61.6
20.6
83.6
8.2
42.9
76.1
125.3
137.1
11.6
65.3
9.1
80.4
2.4
<0.0001
<0.0001
0.005
<0.0001
<0.0001
0.01
<0.0001
0.03
<0.0001
Predictors for Logistic Regression
Variable
SAE No SAE P‐Value
N=147 N=3,887
Highest ED Heart Rate
87.2
84.0
0.05
Highest ED Heart Rate>110/min
12.2
6.4 0.0047
Triage Respiratory Rate
18.0
17.2
0.04
Triage Respiratory Rate >20/min 10.1
3.5 0.0002
Troponin >99th Percentile
25.2
3.4 <0.0001
Hematocrit
0.38
0.40 0.0003
Hematocrit <0.3
9.0
3.5 0.0007
Urea
8.8
6.4 <0.0001
Urea >12mmol/L
15.7
5.6 <0.0001
Creatinine
109.5
88.4 0.0002
Creatinine >150µmol/L
11.7
5.4 0.0012
Predictors for Logistic Regression
Variable
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
SAE No SAE P‐Value
N=147 N=3,887
11.4
2.3 <0.0001
9.9
5.5
0.03
111.1
93.0 <0.0001
31.6
5.1 <0.0001
16.0
35.6 0.0003
32.3
8.3 <0.0001
463.6
431.7 <0.0001
38.4
6.4 <0.0001
13.2
35.4
55.7 <0.0001
5.0 <0.0001