Diagnostic and prognostic value of high-sensitivity cardiac troponin T in patients with syncope

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.

Diagnostic accuracy of high sensitivity troponin and association of electrocardiogram findings for mortality in syncope patients: A retrospective cohort study

High-sensitivity cardiac troponin-T (hs-cTnT) and electrocardiogram (ECG) are commonly ordered in daily practice in emergency medicine but their value on long term mortality in syncope patients is unclear. Our aim is to determine the diagnostic accuracy of hs-cTnT and association of ECG findings for 1-year mortality in patients presenting with syncope. In this retrospective cohort study, we included patients presenting with syncope to the emergency department (ED) between May 2020 and May 2021. Patient demographics, vital parameters on admission, ECG findings, hs-cTnT level at admission and 1-year mortality status were recorded. The study included 417 patients (62.4% women) with a mean age of 41.51 (standard deviation [SD] 17.1), 21 of whom were deceased within 1 year after syncope attack (5%). Patients with an abnormal QTc, T-Axis or frontal QRS-T angle had significantly higher 1-year mortality (OR: 9.26, 95% CI: 1.64-52.31; OR: 5.82, 95% CI: 1.69-20.1; 4.94, 95% CI: 1.45-16.84, respectively). The hs-cTnT level was 21.92 pg/mL (95% CI: 3.35-40.51 pg/mL) higher in the mortality group (P = .023). An abnormal QTc, T-Axis and frontal QRS-T angle are associated with a higher 1-year mortality rate and hs-cTnT has good diagnostic accuracy in detecting 1-year mortality for patients presenting with syncope.

Developing and Demonstrating the Viability and Availability of the Multilevel Implementation Strategy for Syncope Optimal Care Through Engagement (MISSION) Syncope App: Evidence-Based Clinical Decision Support Tool

BACKGROUND

Syncope evaluation and management is associated with testing overuse and unnecessary hospitalizations. The 2017 American College of Cardiology/American Heart Association (ACC/AHA) Syncope Guideline aims to standardize clinical practice and reduce unnecessary services. The use of clinical decision support (CDS) tools offers the potential to successfully implement evidence-based clinical guidelines. However, CDS tools that provide an evidence-based differential diagnosis (DDx) of syncope at the point of care are currently lacking.

OBJECTIVE

With input from diverse health systems, we developed and demonstrated the viability of a mobile app, the Multilevel Implementation Strategy for Syncope optImal care thrOugh eNgagement (MISSION) Syncope, as a CDS tool for syncope diagnosis and prognosis.

METHODS

Development of the app had three main goals: (1) reliable generation of an accurate DDx, (2) incorporation of an evidence-based clinical risk tool for prognosis, and (3) user-based design and technical development. To generate a DDx that incorporated assessment recommendations, we reviewed guidelines and the literature to determine clinical assessment questions (variables) and likelihood ratios (LHRs) for each variable in predicting etiology. The creation and validation of the app diagnosis occurred through an iterative clinician review and application to actual clinical cases. The review of available risk score calculators focused on identifying an easily applied and valid evidence-based clinical risk stratification tool. The review and decision-making factors included characteristics of the original study, clinical variables, and validation studies. App design and development relied on user-centered design principles. We used observations of the emergency department workflow, storyboard demonstration, multiple mock review sessions, and beta-testing to optimize functionality and usability.

RESULTS

The MISSION Syncope app is consistent with guideline recommendations on evidence-based practice (EBP), and its user interface (UI) reflects steps in a real-world patient evaluation: assessment, DDx, risk stratification, and recommendations. The app provides flexible clinical decision making, while emphasizing a care continuum; it generates recommendations for diagnosis and prognosis based on user input. The DDx in the app is deemed a pragmatic model that more closely aligns with real-world clinical practice and was validated using actual clinical cases. The beta-testing of the app demonstrated well-accepted functionality and usability of this syncope CDS tool.

CONCLUSIONS

The MISSION Syncope app development integrated the current literature and clinical expertise to provide an evidence-based DDx, a prognosis using a validated scoring system, and recommendations based on clinical guidelines. This app demonstrates the importance of using research literature in the development of a CDS tool and applying clinical experience to fill the gaps in available research. It is essential for a successful app to be deliberate in pursuing a practical clinical model instead of striving for a perfect mathematical model, given available published evidence. This hybrid methodology can be applied to similar CDS tool development.

Diagnostic value of cardiac troponin I and N-terminal pro-B-Type Natriuretic Peptide in cardiac syncope

Objective

The study aims to evaluate the diagnostic accuracy of Cardiac Troponin I(cTnI) and N-terminal pro-B-Type Natriuretic Peptide (NT-proBNP) for identifying patients with cardiac syncope.

Methods

This is a prospective, single-center cohort study of patients presenting with syncope hospitalized from June 21,2018 to May 30, 2019. The Evaluation of Guidelines in Syncope Study (EGSYS), a syncope-specific diagnostic score, was used for diagnostic comparator.

Results

A total of 118 patients were enrolled (mean age: 69.1 ​± ​12.3 years, 40% female). Compared to patients with reflex, orthostatic, or unexplained syncope, patients adjudicated to have cardiac syncope showed significantly higher cTnI and NT-proBNP plasma concentrations (p ​< ​0.001 for each comparison). The area under the curve (AUC) of cTnI and NT-proBNP were moderate-to-good [0.77–0.78; 95% confidence interval (CI) 0.66–0.86], and was similar to that of EGSYS (0.71, 95%CI 0.60–0.80). Incorporation of cTnI and/or NT-proBNP into the existing EGSYS score significantly improved the diagnostic accuracy (EGSYS ​+ ​cTnI: AUC 0.83; 95%CI 0.74–0.90; EGSYS ​+ ​NT-proBNP: AUC 0.81; 95%CI 0.71–0.89; EGSYS ​+ ​cTnI ​+ ​NT-proBNP: AUC 0.83; 95%CI 0.73–0.90).

Conclusions

The cTnI and NT-proBNP levels were significantly higher in patients adjudicated to have cardiac syncope and the addition of both biomarkers to the EGSYS score significantly improved the diagnostic value for cardiac syncope.

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CTnI and NT-proBNP levels were significantly higher in patients adjudicated to have cardiac syncope.

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Firstly incorporation of cTnI and NT-proBNP to the EGSYS score, which significantly improved the diagnosis value.

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Incorporation of both biomarkers to the EGSYS score significantly improved its predictive performance.

[Diagnostic value of high-sensitivity troponin I to predict cardiac causes after syncope/near syncope in emergency department]

AIMS

The objective of this study is to evaluate the diagnostic accuracy of high-sensitivity (hs) troponin I to predict cardiac origin after syncope. The secondary objective is to determine the causes of elevated troponin.

PROCEDURE

Were included hospitalized patients with syncope/near syncope diagnosed in ED. The diagnostic accuracy to predict cardiac origin was evaluated and compared to the "high risk" group, defined by the 2018 European Society of Cardiology guidelines.

RESULTS

A total of 163 patients were enrolled, 26% had a cardiac origin. Positive troponin I hs predict a cardiac origin with a sensitivity of 31%, a specificity of 80%, positive predictive value of 35% and negative value of 77%. These diagnostic performances are not discriminating and lower than the ESC classification. A positive troponine I hs level is associated with 5 times more cardiac failure during the hospitalization.

CONCLUSION

A positive troponin I hs level after syncope/near syncope is not predictive of cardiac origin. It appears to be an early marker of ventricular remodeling in heart failure.

Did This Patient Have Cardiac Syncope?: The Rational Clinical Examination Systematic Review

IMPORTANCE

Syncope can result from a reduction in cardiac output from serious cardiac conditions, such as arrhythmias or structural heart disease (cardiac syncope), or other causes, such as vasovagal syncope or orthostatic hypotension.

OBJECTIVE

To perform a systematic review of studies of the accuracy of the clinical examination for identifying patients with cardiac syncope.

STUDY SELECTION

Studies of adults presenting to primary care, emergency departments, or referred to specialty clinics.

DATA EXTRACTION AND SYNTHESIS

Relevant data were abstracted from articles in databases through April 9, 2019, and methodologic quality was assessed. Included studies had an independent comparison to a reference standard.

MAIN OUTCOMES AND MEASURES

Sensitivity, specificity, and likelihood ratios (LRs).

RESULTS

Eleven studies of cardiac syncope (N = 4317) were included. Age at first syncope of at least 35 years was associated with greater likelihood of cardiac syncope (n = 323; sensitivity, 91% [95% CI, 85%-97%]; specificity, 72% [95% CI, 66%-78%]; LR, 3.3 [95% CI, 2.6-4.1]), while age younger than 35 years was associated with a lower likelihood (LR, 0.13 [95% CI, 0.06-0.25]). A history of atrial fibrillation or flutter (n = 323; sensitivity, 13% [95% CI, 6%-20%]; specificity, 98% [95% CI, 96%-100%]; LR, 7.3 [95% CI, 2.4-22]), or known severe structural heart disease (n = 222; range of sensitivity, 35%-51%, range of specificity, 84%-93%; range of LR, 3.3-4.8; 2 studies) were associated with greater likelihood of cardiac syncope. Symptoms prior to syncope that were associated with lower likelihood of cardiac syncope were mood change or prodromal preoccupation with details (n = 323; sensitivity, 2% [95% CI, 0%-5%]; specificity, 76% [95% CI, 71%-81%]; LR, 0.09 [95% CI, 0.02-0.38]), feeling cold (n = 412; sensitivity, 2% [95% CI, 0%-5%]; specificity, 89% [95% CI, 85%-93%]; LR, 0.16 [95% CI, 0.06-0.64]), or headache (n = 323; sensitivity, 3% [95% CI, 0%-7%]; specificity, 80% [95% CI, 75%-85%]; LR, 0.17 [95% CI, 0.06-0.55]). Cyanosis witnessed during the episode was associated with higher likelihood of cardiac syncope (n = 323; sensitivity, 8% [95% CI, 2%-14%]; specificity, 99% [95% CI, 98%-100%]; LR, 6.2 [95% CI, 1.6-24]). Mood changes after syncope (n = 323; sensitivity, 3% [95% CI, 0%-7%]; specificity, 83% [95% CI, 78%-88%]; LR, 0.21 [95% CI, 0.06-0.65]) and inability to remember behavior prior to syncope (n = 323; sensitivity, 5% [95% CI, 0%-9%]; specificity, 82% [95% CI, 77%-87%]; LR, 0.25, [95% CI, 0.09-0.69]) were associated with lower likelihood of cardiac syncope. Two studies prospectively validated the accuracy of the multivariable Evaluation of Guidelines in Syncope Study (EGSYS) score, which is based on 6 clinical variables. An EGSYS score of less than 3 was associated with lower likelihood of cardiac syncope (n = 456; range of sensitivity, 89%-91%, range of specificity, 69%-73%; range of LR, 0.12-0.17; 2 studies). Cardiac biomarkers show promising diagnostic accuracy for cardiac syncope, but diagnostic thresholds require validation.

CONCLUSIONS AND RELEVANCE

The clinical examination, including the electrocardiogram as part of multivariable scores, can accurately identify patients with and without cardiac syncope.

B-Type Natriuretic Peptides and Cardiac Troponins for Diagnosis and Risk-Stratification of Syncope

BACKGROUND

The utility of BNP (B-type natriuretic peptide), NT-proBNP (N-terminal proBNP), and hs-cTn (high-sensitivity cardiac troponin) concentrations for diagnosis and risk-stratification of syncope is incompletely understood.

METHODS

We evaluated the diagnostic and prognostic accuracy of BNP, NT-proBNP, hs-cTnT, and hs-cTnI concentrations, alone and against those of clinical assessments, in patients >45-years old presenting with syncope to the emergency department in a prospective diagnostic multicenter study. BNP, NT-proBNP, hs-cTnT and hs-cTnI concentrations were measured in a blinded fashion. Cardiac syncope, as adjudicated by 2 physicians based on all information available including cardiac work-up and 1-year follow-up, was the diagnostic end point. EGSYS (Evaluation of Guidelines in Syncope Study), a syncope-specific diagnostic score, served as the diagnostic comparator. Death and major adverse cardiac events at 30 and 720 days were the prognostic end points. Major adverse cardiac events were defined as death, cardiopulmonary resuscitation, life-threatening arrhythmia, implantation of pacemaker/implantable cardioverter defibrillator, acute myocardial infarction, pulmonary embolism, stroke/transient ischemic attack, intracranial bleeding, or valvular surgery. ROSE (Risk Stratification of Syncope in the Emergency Department), OESIL (Osservatorio Epidemiologico della Sincope nel Lazio), SFSR (San Fransisco Syncope Rule), and CSRS (Canadian Syncope Risk Score) served as the prognostic comparators.

RESULTS

Among 1538 patients eligible for diagnostic assessment, cardiac syncope was the adjudicated diagnosis in 234 patients (15.2%). BNP, NT-proBNP, hs-cTnT, and hs-cTnI were significantly higher in cardiac syncope versus other causes (P<0.01). The diagnostic accuracy for cardiac syncope, as quantified by the area under the curve, was 0.77 to 0.78 (95% CI, 0.74-0.81) for all 4 biomarkers, and superior to EGSYS (area under the curve, 0.68 [95%-CI 0.65-0.71], P<0.001). Combining BNP/NT-proBNP with hs-cTnT/hs-cTnI further improved diagnostic accuracy to an area under the curve of 0.81 (P<0.01). BNP, NT-proBNP, hs-cTnT, and hs-cTnI cut-offs, achieving predefined thresholds for sensitivity and specificity (95%), allowed for rule-in or rule-out of ≈30% of all patients. A total of 450 major adverse cardiac events occurred during follow-up. The prognostic accuracy of BNP, NT-proBNP, hs-cTnI, and hs-cTnT for major adverse cardiac events was moderate-to-good (area under the curve, 0.75-0.79), superior to ROSE, OESIL, and SFSR, and inferior to CSRS.

CONCLUSIONS

BNP, NT-proBNP, hs-cTnT, and hs-cTnI concentrations provide useful diagnostic and prognostic information in emergency department patients with syncope.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT01548352.

Review article: Utility of troponin after syncope: A systematic review and meta-analysis

The role of serum troponin testing in patients presenting to the ED after syncope is unclear. The aim of this systematic review was to examine the practice and utility of troponin testing among patients presenting to the ED after syncope. We conducted a search of MEDLINE, Embase, Cochrane Library, Web of Science and Scopus databases from 1990 to February 2017 using keyword and subject headings for syncope and troponin testing. Design and results of the included studies are extracted. Studies were assessed for heterogeneity and the pooled proportion of measured troponin and positive troponin result described. There were nine studies included for analysis. Significant statistical heterogeneity among studies was observed (P < 0.001). Using the random effects model, the pooled proportion of patients presenting to the ED after syncope who had troponin measured was 0.64 (95% CI 0.46-0.82). Among patients who had been troponin tested, the pooled proportion who had a positive result was 0.19 (95% CI 0.13-0.26). Variability among reported outcomes prevented further meta-analysis. Troponin testing was commonly performed for the assessment of patients with syncope with a substantial proportion returning positive results. The correlation between raised troponin and patient outcomes was not adequately reported. It is possible that an elevated troponin may indicate serious illness, rather than myocardial damage alone.

Predicting Short-term Risk of Arrhythmia among Patients With Syncope: The Canadian Syncope Arrhythmia Risk Score

BACKGROUND

Syncope can be caused by serious occult arrhythmias not evident during initial emergency department (ED) evaluation. We sought to develop a risk tool for predicting 30-day arrhythmia or death after ED disposition.

METHODS

We conducted a multicenter prospective cohort study at six tertiary care EDs and included adults (≥16 years) with syncope. We collected standardized variables from clinical evaluation and investigations including electrocardiogram and troponin at index presentation. Adjudicated outcomes included death or arrhythmias including procedural interventions for arrhythmia within 30 days. We used multivariable logistic regression to derive the prediction model and bootstrapping for interval validation to estimate shrinkage and optimism.

RESULTS

A total of 5,010 patients (mean ± SD age = 53.4 ± 23.0 years, 54.8% females, and 9.5% hospitalized) were enrolled with 106 (2.1%) patients suffering 30-day arrhythmia/death after ED disposition. We examined 39 variables and eight were included in the final model: lack of vasovagal predisposition, heart disease, any ED systolic blood pressure < 90 or > 180 mm Hg, troponin (>99th percentile), QRS duration > 130 msec, QTc interval > 480 msec, and ED diagnosis of cardiac/vasovagal syncope (optimism corrected C-statistic 0.90 [95% CI = 0.87-0.93]; Hosmer-Lemeshow p = 0.08). The Canadian Syncope Arrhythmia Risk Score had a risk ranging from 0.2% to 74.5% for scores of -2 to 8. At a threshold score of ≥0, the sensitivity was 97.1% (95% CI = 91.6%-99.4%) and specificity was 53.4% (95% CI = 52.0%-54.9%).

CONCLUSIONS

The Canadian Syncope Arrhythmia Risk Score can improve patient safety by identification of those at risk for arrhythmias and aid in acute management decisions. Once validated, the score can identify low-risk patients who will require no further investigations.

[Troponin elevation in the absence of acute coronary syndrome]

Cardiac troponins are the most sensitive and specific markers of myocardial injury. Cardiac troponin elevation are common in many diseases and do not necessarily indicate the presence of a thrombotic acute coronary syndrome. In clinical practice, interpretation of dynamic changes of troponin may be challenging. Troponin evaluation should be performed only if clinically indicated and must be interpreted in the context of clinical presentation, ECG changes, troponin level and kinetic. In the absence of thrombotic acute coronary syndrom, troponin retains a prognostic value. Its practical interest as a risk criteria is limited to a few situations like pulmonary embolism, pericarditis an myocarditis.

Prognostic value of cardiac biomarkers in the risk stratification of syncope: a systematic review

The role of cardiac biomarkers in risk stratification of syncope is unclear. We undertook a systematic review to assess their predictive value for short-term major adverse cardiovascular events (MACE). We conducted a systematic review using MEDLINE, EMBASE, DARE and Cochrane databases from inception to July 2014. We included studies involving adult syncope patients that evaluated cardiac biomarker levels for risk stratification during acute management and excluded case reports, reviews and studies involving children. Primary outcome (MACE) included death, cardiopulmonary resuscitation, myocardial infarction (MI), structural heart disease, pulmonary embolism, significant hemorrhage or cardiac procedural interventions. Secondary outcome analysis assessed for prediction of MI, cardiac syncope and death. Two reviewers extracted patient-level data based on the cut-off reported. Pooled sensitivities and specificities were calculated using patient-level data. A total of 1862 articles were identified, and 11 studies with 4246 patients were included. Studies evaluated 3 biomarkers: contemporary troponin (2693 patients), natriuretic peptides (1353 patients) and high-sensitive troponin (819 patients). The pooled sensitivities and specificities for MACE were: contemporary troponin 0.29 (95 % CI 0.24, 0.34) and 0.88 (95 % CI 0.86, 0.89); natriuretic peptides 0.77 (95 % CI 0.69, 0.85) and 0.73 (95 % CI 0.70, 0.76); high-sensitive troponin 0.74 (95 % CI 0.65, 0.83) and 0.65 (95 % CI 0.62, 0.69), respectively. Natriuretic peptides and high-sensitive troponin showed good diagnostic characteristics for both primary and secondary outcomes. Natriuretic peptides and high-sensitive troponin might be useful in risk stratification.

Syncope: the emergency department and beyond

Syncope is a common problem encountered by both emergency and internal medicine physicians. This review focuses on not only the assessment, risk stratification and management of the syncope patient, but also the latest thinking on diagnostic testing including more novel tools such as biomarkers and ambulatory patch monitor recording.