Introduction

The ROSE (Risk Stratification of Syncope in the Emergency Department) Rule is a clinical decision tool designed to identify emergency department (ED) patients presenting with syncope who are at high risk of serious adverse outcomes within one month of their index visit. Developed by Reed and colleagues at the Royal Infirmary of Edinburgh and published in the Journal of the American College of Cardiology in 2010, the ROSE rule uses a simple, mnemonic-based set of criteria known as BRACES to stratify patients into low-risk and high-risk categories, with the primary goal of safely guiding disposition decisions.

Syncope accounts for approximately 1-3% of all emergency department visits and 1-6% of hospital admissions, representing a significant burden on emergency healthcare resources. The challenge for the emergency physician is that the differential diagnosis for syncope ranges from benign vasovagal episodes (which require no treatment) to life-threatening conditions such as cardiac arrhythmias, acute coronary syndromes, pulmonary embolism, and gastrointestinal hemorrhage. Historically, a large proportion of syncope patients have been admitted for observation and workup, yet many of these admissions yield no serious diagnosis, leading to unnecessary resource utilization, patient inconvenience, and healthcare costs.

The ROSE rule was developed to address this clinical dilemma by providing an evidence-based framework that identifies a low-risk population suitable for safe ED discharge while flagging high-risk patients who warrant admission and further investigation. Its binary design (any single positive BRACES criterion = high risk; no positive criteria = low risk) prioritizes sensitivity over specificity, reflecting the critical importance of not missing life-threatening diagnoses in the syncope population.

Development and Validation

Study Design and Derivation Cohort

The ROSE study was a prospective observational cohort study conducted at the Royal Infirmary of Edinburgh, a large teaching hospital in the United Kingdom. The derivation phase enrolled 550 consecutive adult patients (aged 16 years and older) who presented to the ED with syncope or near-syncope (presyncope) between 2006 and 2007. Syncope was defined as a transient loss of consciousness with spontaneous recovery, consistent with the European Society of Cardiology (ESC) definition.

The primary outcome was the occurrence of a serious adverse outcome within one month of the index ED visit, defined as:

• All-cause death
• Acute myocardial infarction
• Life-threatening arrhythmia (requiring pacemaker or ICD implantation, or producing hemodynamic instability)
• Pulmonary embolism
• Cerebrovascular accident (stroke or TIA)
• Subarachnoid hemorrhage
• Significant hemorrhage requiring transfusion
• Acute surgical condition requiring emergency procedure
• Any other condition leading to hospital readmission within 30 days related to the syncope episode

From the derivation cohort, multiple candidate predictor variables were evaluated using logistic regression analysis. The final model identified seven clinical variables that formed the BRACES mnemonic. These variables were selected based on their independent predictive value for serious outcomes, their availability within routine ED assessment (clinical evaluation, basic blood work, and a 12-lead ECG), and their suitability for a practical bedside tool.

Validation Cohort

The ROSE rule was prospectively validated in a separate cohort of 550 patients from the same institution. In the validation cohort, the rule achieved:

Performance Metric	Value
Sensitivity	87.2%
Specificity	65.5%
Negative Predictive Value (NPV)	98.5%
Positive Predictive Value (PPV)	21.0%

The high NPV of 98.5% is the clinically most important metric: when no BRACES criteria are present, there is a 98.5% probability that the patient will not experience a serious adverse outcome within one month. This high NPV makes the rule particularly useful as a "rule-out" tool, providing clinicians with evidence-based reassurance to support safe discharge of low-risk patients.

Key Design Principles

Several design principles distinguished the ROSE study from earlier syncope risk stratification efforts:

• Inclusion of BNP: The ROSE study was one of the first syncope risk stratification tools to incorporate B-type natriuretic peptide (BNP) as a biomarker predictor. BNP emerged as the single strongest independent predictor of serious outcomes in the derivation cohort, reflecting its ability to detect underlying cardiac dysfunction (heart failure, valvular disease, cardiomyopathy) that predisposes to arrhythmias and hemodynamic compromise.
• Inclusion of fecal occult blood: The incorporation of rectal examination with fecal occult blood testing was novel among syncope decision rules and reflects the clinical reality that occult gastrointestinal hemorrhage is an underrecognized cause of syncope, particularly in elderly patients.
• Binary decision threshold: Unlike scoring systems that require tallying points and consulting risk tables, the ROSE rule uses a simple binary threshold: any single positive criterion triggers a high-risk classification. This design maximizes ease of use at the bedside and minimizes the cognitive burden during a busy ED shift.
• One-month outcome window: The 30-day follow-up period captures both immediate complications (e.g., arrhythmias in the first 24-72 hours) and short-term outcomes (e.g., recurrent syncope leading to readmission, delayed presentation of pulmonary embolism), providing a clinically meaningful risk assessment horizon.

The BRACES Criteria

The BRACES mnemonic encodes seven clinical criteria across six letters (the letter B encompasses two criteria: BNP and Bradycardia). Each criterion is assessed as present or absent, and the presence of any single criterion classifies the patient as high risk.

B: BNP ≥ 300 pg/mL

B-type natriuretic peptide (BNP) is a cardiac neurohormone released primarily by ventricular cardiomyocytes in response to myocardial wall stress from volume overload or pressure overload. In the ROSE derivation cohort, BNP ≥ 300 pg/mL was the strongest independent predictor of serious adverse outcomes.

An elevated BNP in the context of syncope suggests underlying cardiac pathology that may not be immediately apparent on physical examination or ECG:

• Heart failure (systolic or diastolic): Reduced cardiac output predisposes to hypotension-mediated syncope, particularly during orthostatic stress or exercise. Concomitant atrial or ventricular arrhythmias are common in heart failure and represent a major cause of sudden cardiac death.
• Valvular heart disease: Aortic stenosis is the classic valvular cause of exertional syncope. Other valvular lesions (mitral regurgitation, mitral stenosis) can produce hemodynamic compromise. BNP is elevated proportionally to the severity of valvular dysfunction.
• Hypertrophic cardiomyopathy: Left ventricular outflow tract obstruction and diastolic dysfunction produce elevated BNP and predispose to exertional syncope and ventricular arrhythmias.
• Pulmonary embolism: Right ventricular strain from acute PE elevates BNP. Syncope is the presenting symptom in approximately 10% of pulmonary embolism cases and is associated with hemodynamically significant (massive or submassive) PE.
• Pulmonary hypertension: Chronic right heart overload from any cause of pulmonary hypertension elevates BNP and can produce exertional syncope.

The 300 pg/mL threshold was selected to optimize the discriminative ability of BNP within the syncope population. This is higher than the typical heart failure diagnostic threshold (100 pg/mL), reflecting the need for greater specificity in a population where mild BNP elevations are common due to age, renal dysfunction, and other comorbidities.

Practical Note: If NT-proBNP is used instead of BNP, an approximate equivalent threshold of 900-1000 pg/mL may be considered, though the ROSE rule was specifically derived and validated using BNP. Clinicians should be aware of assay-specific differences and institutional reference ranges.

B: Bradycardia ≤ 50 bpm (ED or Prehospital)

A heart rate of 50 beats per minute or less, documented either in the prehospital setting (by emergency medical services) or during the ED evaluation, is the second criterion under the B letter. Bradycardia in the context of syncope raises concern for several potentially serious conditions:

• Sinus node dysfunction (sick sinus syndrome): Failure of the sinoatrial node to generate impulses at an adequate rate, producing symptomatic bradycardia, sinus pauses, or the tachy-brady syndrome.
• Atrioventricular (AV) block: Second-degree (Mobitz type II) or third-degree (complete) AV block can produce syncope from inadequate ventricular rate and hemodynamic compromise. Intermittent high-grade AV block may produce syncope (Stokes-Adams attacks) with normal sinus rhythm between episodes.
• Medication-induced bradycardia: Beta-blockers, non-dihydropyridine calcium channel blockers (verapamil, diltiazem), digoxin, amiodarone, and other antiarrhythmics can produce symptomatic bradycardia, particularly in combination or in the setting of renal impairment.
• Hyperkalemia: Severe hyperkalemia can produce bradycardia and conduction abnormalities that may present as syncope.
• Hypothermia: Core temperature below 35 degrees Celsius produces bradycardia and may contribute to syncope in exposure settings.

The exclusion of well-conditioned athletes from this criterion reflects the physiologic bradycardia (high vagal tone) common in endurance-trained individuals, which is typically asymptomatic and benign. In an athletic patient with syncope and a resting heart rate below 50 bpm, clinical judgment should weigh the bradycardia in the context of the overall presentation rather than automatically triggering a high-risk classification.

R: Rectal Examination Positive for Fecal Occult Blood

A positive fecal occult blood test (FOBT) on rectal examination performed in the ED indicates the presence of blood in the stool, suggesting possible gastrointestinal hemorrhage. GI bleeding is a frequently underrecognized cause of syncope, particularly in older patients who may not report overt bleeding symptoms:

• Upper GI hemorrhage: Peptic ulcer disease, esophageal varices, Mallory-Weiss tears, erosive gastritis, and upper GI malignancies can produce significant blood loss. Syncope may be the presenting symptom before melena or hematemesis becomes clinically apparent.
• Lower GI hemorrhage: Diverticular bleeding, angiodysplasia, colorectal neoplasia, and inflammatory bowel disease can cause chronic or acute blood loss.
• Hypovolemia-mediated syncope: Acute blood loss reduces circulating volume and preload, producing orthostatic hypotension and, with sufficient volume depletion, frank syncope from global cerebral hypoperfusion.

The inclusion of FOBT as a ROSE criterion is distinctive among syncope decision rules and reflects the observation from the derivation cohort that occult GI blood loss was a significant contributor to serious outcomes that would have been missed by tools focusing exclusively on cardiac and neurologic etiologies.

Practical Note: The utility and appropriateness of routine digital rectal examination in ED syncope patients has been debated. Some clinicians may not routinely perform rectal examination in every syncope patient. When rectal examination is omitted, this criterion cannot be assessed, and the clinician should note this limitation in their risk assessment. Point-of-care guaiac or immunochemical fecal occult blood tests can be used.

A: Anemia (Hemoglobin ≤ 90 g/L)

Hemoglobin at or below 90 g/L (9.0 g/dL) indicates significant anemia that may contribute to syncope through impaired oxygen delivery to the brain. The threshold of 90 g/L was selected as the optimal discriminative cut-point in the derivation analysis, representing a level of anemia that is clinically significant across most patient populations.

Anemia may contribute to syncope through several mechanisms:

• Reduced oxygen-carrying capacity: Hemoglobin is the primary oxygen carrier in blood. At levels below 90 g/L, compensatory mechanisms (increased cardiac output, enhanced oxygen extraction) may be insufficient to maintain adequate cerebral oxygenation, particularly during orthostatic stress or exertion.
• High-output cardiac state: Chronic anemia produces a compensatory increase in heart rate and stroke volume, which can unmask or exacerbate underlying cardiac disease (precipitating angina, heart failure decompensation, or arrhythmias).
• Marker of active bleeding: In the acute setting, anemia may indicate ongoing hemorrhage (GI, retroperitoneal, musculoskeletal after trauma) that requires urgent intervention.
• Marker of chronic disease: Chronic anemia from malignancy, chronic kidney disease, or nutritional deficiency may indicate an underlying condition that contributes to syncope risk.

C: Chest Pain Associated with Syncope

The presence of chest pain in temporal association with the syncope episode is a red flag that raises concern for several high-acuity diagnoses:

• Acute coronary syndrome (ACS): Myocardial ischemia or infarction can produce syncope through vagally mediated reflex bradycardia and hypotension (Bezold-Jarisch reflex), ventricular tachycardia or fibrillation, or pump failure with cardiogenic shock. Syncope is the presenting symptom in approximately 3-5% of patients with acute MI.
• Pulmonary embolism (PE): Large or submassive PE can produce pleuritic chest pain, dyspnea, and syncope from acute right ventricular failure and reduced left ventricular preload. Syncope is one of the most ominous presentations of PE, associated with higher mortality.
• Aortic dissection: Acute aortic dissection (particularly Stanford type A involving the ascending aorta) can produce severe, tearing chest pain and syncope from cardiac tamponade, acute aortic regurgitation, coronary artery compromise, or hypovolemic shock from aortic rupture.
• Tension pneumothorax: Though less common, tension pneumothorax can produce chest pain, respiratory distress, and syncope from mediastinal shift and impaired venous return.
• Cardiac tamponade: Pericardial effusion with hemodynamic compromise produces Beck's triad (hypotension, muffled heart sounds, jugular venous distension) and can present with syncope.

Any patient presenting with syncope accompanied by chest pain requires a thorough evaluation for these life-threatening diagnoses, typically including serial ECGs, troponin, chest imaging, and consideration of CT angiography.

E: ECG Showing Q-Wave (Not in Lead III)

Pathological Q-waves on the 12-lead ECG indicate prior myocardial infarction and are a marker of structural heart disease. In the context of syncope, their significance includes:

• Myocardial scar and arrhythmia substrate: Prior myocardial infarction creates areas of scar tissue that serve as re-entrant circuits for ventricular tachycardia (VT). VT is a major cause of syncope and sudden cardiac death in patients with ischemic cardiomyopathy.
• Reduced ventricular function: Q-waves correlate with regional wall motion abnormalities and may indicate reduced left ventricular ejection fraction, predisposing to both tachyarrhythmias and hemodynamic instability.
• Risk for recurrent ischemic events: Patients with prior MI are at increased risk for recurrent ACS, which may present as syncope.

The ROSE rule specifies that Q-waves in lead III alone are excluded from this criterion because isolated Q-waves in lead III are a common normal variant (particularly in younger patients and during deep inspiration) and do not reliably indicate prior infarction. Q-waves in other leads (especially leads V1-V6 in anterior distributions, or leads II, aVF, and III together in inferior distributions) carry greater pathological significance.

S: Oxygen Saturation ≤ 94% on Room Air

Hypoxemia, defined as oxygen saturation at or below 94% on room air by pulse oximetry, is the final BRACES criterion. Low oxygen saturation in a syncope patient suggests an underlying cardiopulmonary process:

• Pulmonary embolism: Hypoxemia from ventilation-perfusion mismatch is a hallmark of PE. When combined with syncope, hypoxemia strongly suggests hemodynamically significant PE requiring urgent evaluation and treatment.
• Pneumonia: Respiratory infection with parenchymal involvement can produce hypoxemia and, through systemic inflammatory responses and dehydration, contribute to syncope.
• Acute heart failure/pulmonary edema: Cardiogenic pulmonary edema produces hypoxemia from impaired gas exchange and is associated with the cardiac conditions that predispose to arrhythmic syncope.
• Chronic obstructive pulmonary disease (COPD) exacerbation: Acute exacerbations can produce hypoxemia, hypercapnia, and hemodynamic changes that contribute to syncope.
• Aspiration: Syncope itself can lead to aspiration, producing secondary hypoxemia. This may complicate the clinical picture and require additional management.

The 94% threshold on room air was selected as the optimal cut-point in the derivation analysis. Patients on supplemental oxygen at baseline should have their oxygen assessment interpreted in context; a saturation of 94% on 4 liters of supplemental oxygen is more concerning than 94% on room air.

Score Interpretation and Risk Stratification

The ROSE rule uses a simple binary classification:

BRACES Criteria Positive	Risk Classification	Recommended Action
0 criteria	Low Risk	Safe for ED discharge with appropriate outpatient follow-up and clear return precautions
≥1 criterion	High Risk	Hospital admission recommended for further evaluation, cardiac monitoring, and targeted workup

This binary structure is intentionally conservative: a single positive criterion is sufficient to classify a patient as high risk. The rationale is that the consequences of missing a serious diagnosis (death, MI, arrhythmia) far outweigh the costs of a potentially unnecessary admission. The rule is designed to maximize sensitivity (minimizing false negatives) at the expense of specificity (accepting some false positives).

Low-Risk Patients

Patients with no positive BRACES criteria have a 98.5% probability of not experiencing a serious adverse outcome within one month. For these patients, the ROSE rule supports safe ED discharge, provided:

• Clinical judgment is concordant with the low-risk classification (the ROSE rule is a decision support tool, not a substitute for clinical assessment).
• The patient receives clear discharge instructions including return precautions (recurrent syncope, chest pain, palpitations, dyspnea, new neurological symptoms).
• Outpatient follow-up is arranged, ideally within 1-2 weeks, with the patient's primary care physician or a specialist (cardiology, neurology) as appropriate for the clinical presentation.
• The patient has an adequate social support system for safe observation at home.

High-Risk Patients

Patients with one or more positive BRACES criteria should be admitted for further evaluation. The specific workup should be guided by the positive criteria:

• Positive BNP: Echocardiography, continuous telemetry monitoring, cardiology consultation, evaluation for heart failure etiology.
• Bradycardia: Continuous telemetry, assessment for AV block and sinus node dysfunction, medication review, electrolyte panel, consideration of electrophysiology consultation.
• Positive fecal occult blood: Serial hemoglobin/hematocrit, type and screen, GI consultation, consideration of upper and/or lower endoscopy.
• Anemia: Investigation of anemia etiology (iron studies, reticulocyte count, GI evaluation if iron deficiency), transfusion as indicated, hemodynamic monitoring.
• Chest pain: Serial troponin, serial ECGs, chest imaging, consideration of CT angiography for PE or aortic dissection, cardiology consultation.
• ECG Q-waves: Echocardiography, continuous telemetry, troponin to rule out acute ischemia, cardiology consultation, consideration of electrophysiology study.
• Low oxygen saturation: Chest X-ray, consideration of CT pulmonary angiography, arterial blood gas, assessment for pneumonia and heart failure.

Comparison with Other Syncope Risk Stratification Tools

Several clinical decision rules have been developed for ED syncope risk stratification. Understanding how the ROSE rule compares with these tools helps contextualize its strengths and appropriate use:

San Francisco Syncope Rule (SFSR)

The SFSR uses the CHESS mnemonic: Congestive heart failure history, Hematocrit <30%, ECG abnormality, Shortness of breath, and Systolic blood pressure <90 mmHg. Published in 2004, it was one of the earliest syncope decision rules.

Feature	SFSR (CHESS)	ROSE (BRACES)
Biomarker	None (uses hematocrit only)	BNP ≥ 300 pg/mL
GI bleeding assessment	Hematocrit <30% (indirect)	Fecal occult blood (direct) + Hb ≤90 g/L
ECG criterion	Any ECG abnormality (broad)	Q-wave not in lead III (specific)
Cardiac criterion	CHF history	BNP (objective measurement)
Validation	Mixed results; some external validations failed to replicate sensitivity	Prospectively validated; requires further external validation
Sensitivity	96% (original); 74-90% (external validations)	87.2%
Specificity	62% (original)	65.5%

A key advantage of the ROSE rule over the SFSR is the inclusion of BNP, which provides an objective, quantitative assessment of cardiac dysfunction rather than relying on historical diagnosis of heart failure. The SFSR has been criticized for its broad ECG criterion ("any abnormality"), which reduces specificity.

OESIL Score

The OESIL (Osservatorio Epidemiologico sulla Sincope nel Lazio) score uses four variables: age >65, history of cardiovascular disease, syncope without prodrome, and abnormal ECG. Each variable scores one point, with higher scores indicating greater 12-month mortality risk. The OESIL score was derived in an Italian cohort and focuses on mortality prediction rather than 30-day serious outcomes.

Boston Syncope Rule

The Boston Syncope Rule incorporates a broad set of clinical, ECG, and historical variables to predict 30-day serious outcomes. While it achieved high sensitivity (97%) in its derivation study, its complexity (multiple criteria across several categories) limits practical bedside application compared to the simpler BRACES mnemonic.

Canadian Syncope Risk Score (CSRS)

The CSRS, published in 2016, is a weighted scoring system that stratifies 30-day serious outcome risk across multiple levels (very low to very high). It incorporates clinical features (predisposition, prodrome), hemodynamic parameters, ECG findings, troponin, and ED diagnosis. The CSRS offers more granular risk stratification than the binary ROSE rule but requires more variables and calculation. It has been validated in large multicenter cohorts and is increasingly adopted in Canadian and European practice.

European Society of Cardiology (ESC) 2018 Guidelines

The ESC syncope guidelines recommend a structured approach to syncope evaluation that incorporates initial assessment (history, physical examination, ECG), risk stratification, and targeted investigation. While not a specific scoring tool, the ESC framework identifies high-risk features that overlap substantially with the BRACES criteria (ECG abnormalities, structural heart disease markers, hemodynamic instability). The ROSE rule aligns with the ESC approach and can serve as a practical bedside implementation of the risk stratification principles articulated in the guidelines.

Pathophysiology of Syncope: Framework for Understanding BRACES Criteria

Understanding why each BRACES criterion predicts adverse outcomes requires familiarity with the pathophysiology of syncope. Syncope results from transient global cerebral hypoperfusion, which can arise through three principal mechanisms:

Reflex (Neurally Mediated) Syncope

The most common cause of syncope, accounting for approximately 60% of cases. Reflex syncope involves inappropriate activation of cardiovascular reflexes, producing vasodilation (vasodepressor response), bradycardia (cardioinhibitory response), or both (mixed response). Subtypes include vasovagal syncope, situational syncope (cough, micturition, defecation), and carotid sinus hypersensitivity. Reflex syncope is generally benign, and patients with isolated reflex syncope typically have no positive BRACES criteria, correctly classifying them as low risk.

Cardiac Syncope

Cardiac causes account for approximately 10-20% of syncope and carry the highest mortality risk. Cardiac syncope includes:

• Arrhythmic syncope: Bradyarrhythmias (sinus node dysfunction, AV block) and tachyarrhythmias (ventricular tachycardia, supraventricular tachycardia with rapid ventricular response) reduce cardiac output below the threshold for cerebral perfusion. BRACES criteria B (bradycardia) and E (Q-waves indicating arrhythmia substrate) target this mechanism.
• Structural cardiac disease: Aortic stenosis, hypertrophic cardiomyopathy, cardiac tumors (atrial myxoma), and prosthetic valve dysfunction produce hemodynamic compromise, particularly during exertion. BRACES criterion B (BNP) targets this mechanism.
• Cardiopulmonary vascular disease: Pulmonary embolism, pulmonary hypertension, and aortic dissection produce acute right or left heart failure. BRACES criteria B (BNP), C (chest pain), and S (oxygen saturation) target these conditions.

Orthostatic Syncope

Orthostatic hypotension (a sustained drop in systolic BP ≥20 mmHg or diastolic BP ≥10 mmHg within 3 minutes of standing) produces syncope through inadequate postural compensation. Causes include hypovolemia (dehydration, hemorrhage), autonomic dysfunction (diabetic neuropathy, Parkinson's disease, pure autonomic failure), and medication effects (antihypertensives, diuretics, alpha-blockers). BRACES criteria R (fecal occult blood) and A (anemia) target hypovolemia from GI hemorrhage as a cause of orthostatic syncope.

Strengths and Limitations

Strengths

• Simplicity: The BRACES mnemonic is easy to remember and apply at the bedside without calculation or software. The binary outcome (positive/negative) is straightforward and does not require interpretation of a numeric score.
• High negative predictive value: At 98.5%, the NPV provides strong reassurance that low-risk patients (no BRACES criteria) can be safely discharged.
• Incorporation of BNP: The inclusion of a cardiac biomarker provides objective, quantitative data that supplements clinical and ECG assessment, detecting subclinical cardiac dysfunction that may not be apparent on history or physical examination.
• Comprehensive etiology coverage: The BRACES criteria span cardiac (BNP, bradycardia, Q-waves), hemorrhagic (fecal occult blood, anemia), ischemic (chest pain, Q-waves), and pulmonary (oxygen saturation) etiologies, providing broad coverage of the serious conditions underlying syncope.
• Prospective validation: The rule was prospectively derived and validated in a separate cohort, providing a stronger evidence base than retrospectively derived tools.

Limitations

• Single-center derivation and validation: Both the derivation and validation cohorts were drawn from a single UK hospital, raising questions about generalizability to other populations, healthcare systems, and practice settings. External validation in multicenter, multinational cohorts is needed.
• Moderate sensitivity (87.2%): While the NPV is high, the sensitivity of 87.2% means that approximately 13% of patients with serious outcomes may be missed (false negatives). No syncope decision rule achieves 100% sensitivity, and clinical judgment must always supplement any decision tool.
• Moderate specificity (65.5%): About one-third of patients are classified as high risk who will not have a serious adverse outcome (false positives), potentially leading to unnecessary admissions. This is an inherent trade-off of a rule designed to prioritize sensitivity.
• BNP availability: Not all emergency departments have point-of-care BNP testing available 24/7 with rapid turnaround. If BNP cannot be obtained in a timely manner, this criterion cannot be assessed, reducing the utility of the rule.
• Rectal examination requirement: The fecal occult blood criterion requires digital rectal examination, which may not be routinely performed in all syncope patients. The omission of this test leaves a gap in the BRACES assessment.
• Does not account for age, comorbidities, or historical features: Unlike some competing tools (CSRS, ESC risk features), the ROSE rule does not incorporate patient age, prior syncope history, family history of sudden death, medication use, or syncope circumstances (exertional, supine) into the risk assessment. These features may provide important prognostic information that the BRACES criteria alone do not capture.
• Does not address intermediate risk: The binary low/high classification does not identify an intermediate-risk group that might benefit from observation unit management (e.g., 6-24 hour telemetry monitoring) rather than full hospital admission. Some patients with a single borderline criterion may be overtriaged to inpatient admission.

Special Populations and Clinical Considerations

Elderly Patients

Syncope in older adults (≥65 years) carries a higher baseline risk of serious adverse outcomes and mortality compared to younger patients. The elderly are more likely to have underlying cardiac disease, polypharmacy-related syncope, orthostatic hypotension from autonomic dysfunction, and occult GI bleeding. Multiple BRACES criteria may be positive simultaneously, and the index of suspicion for serious pathology should be correspondingly higher. Additionally, falls associated with syncope in the elderly carry significant morbidity from fractures (hip, vertebral, skull) and traumatic brain injury, adding a layer of risk not directly captured by the BRACES criteria.

Young Adults and Athletes

In young, otherwise healthy adults, vasovagal syncope is by far the most common cause, and the pretest probability of serious cardiac or hemorrhagic pathology is low. The ROSE rule may be particularly useful in this population for its "rule-out" capability: a young patient with a typical vasovagal presentation and no BRACES criteria can be discharged with high confidence. However, clinicians should remain vigilant for rare but serious causes of syncope in the young, including hypertrophic cardiomyopathy, long QT syndrome, Brugada syndrome, Wolff-Parkinson-White syndrome, and arrhythmogenic right ventricular cardiomyopathy (ARVC), some of which may not be captured by the BRACES criteria (e.g., a structurally normal heart with a channelopathy will have a normal BNP and no Q-waves). A careful ECG review for these conditions should supplement BRACES assessment.

Patients on Anticoagulation

Patients on anticoagulant therapy (warfarin, direct oral anticoagulants) who present with syncope warrant heightened concern for hemorrhagic complications. Occult GI bleeding may be more common and more significant in anticoagulated patients, and traumatic intracranial hemorrhage following a syncopal fall is a critical consideration. The BRACES criteria (fecal occult blood, anemia) may detect GI bleeding, but intracranial hemorrhage requires separate assessment (typically CT head). A low threshold for head imaging is appropriate in anticoagulated syncope patients, particularly those with evidence of head trauma or loss of consciousness duration longer than typical for simple syncope.

Recurrent Syncope

Patients with recurrent syncope episodes present a complex management challenge. While recurrent vasovagal syncope is common and generally benign, recurrent syncope may also indicate intermittent cardiac arrhythmias (paroxysmal AV block, paroxysmal VT), which may not be detectable at the time of ED evaluation. The ROSE rule assesses the patient's risk profile at the time of the current presentation and does not directly account for the recurrence pattern. Patients with recurrent syncope of unclear etiology, even if low-risk by BRACES, may benefit from outpatient cardiac monitoring (Holter monitor, event recorder, or implantable loop recorder) to capture the rhythm during a spontaneous event.

Presyncope (Near-Syncope)

The original ROSE study included patients with both syncope and presyncope (near-syncope). Presyncope, defined as the sensation of impending loss of consciousness without actual loss of consciousness, shares the same differential diagnosis as syncope and carries a similar risk of adverse outcomes. The BRACES criteria should be applied equally to presyncope patients. Clinicians should not dismiss presyncope as a benign condition simply because the patient did not fully lose consciousness.

Practical Implementation in the Emergency Department

Integrating the ROSE rule into ED workflow involves the following practical steps:

Standardized Assessment Protocol

1. Initial assessment: History (circumstances of syncope, prodromal symptoms, associated symptoms including chest pain), physical examination (vital signs including orthostatic measurements, cardiac examination, neurological examination), and 12-lead ECG.
2. Laboratory testing: BNP (or NT-proBNP), complete blood count (hemoglobin), and fecal occult blood test (if rectal examination performed). These tests are often part of a standard syncope workup and do not represent additional resource utilization beyond routine care.
3. BRACES assessment: Once clinical data, labs, and ECG are available, systematically evaluate each of the seven BRACES criteria.
4. Risk classification: If all criteria are negative, classify as low risk. If any criterion is positive, classify as high risk.
5. Disposition decision: Integrate the BRACES classification with overall clinical judgment to guide disposition (discharge vs. admission vs. observation unit).

Documentation

When using the ROSE rule to support clinical decision-making, documentation should include:

• The specific BRACES criteria evaluated and their results (positive or negative).
• The overall risk classification (low or high).
• The clinical reasoning linking the risk classification to the disposition decision.
• Any factors that override or modify the rule-based recommendation (e.g., clinical suspicion for a serious diagnosis despite negative BRACES, or a clear benign etiology despite a single positive criterion).

Shared Decision-Making

For low-risk patients, the ROSE rule can be a useful tool for shared decision-making, helping clinicians explain to patients why discharge is appropriate and what the risk level is. Communicating the 98.5% NPV in patient-friendly terms ("based on this assessment, there is less than a 2% chance of a serious problem developing in the next month") can provide reassurance and facilitate adherence to outpatient follow-up plans.

Integration with Other Tools

The ROSE rule need not be used in isolation. In practice, clinicians may combine BRACES assessment with other risk stratification approaches (ESC high-risk features, CSRS, or institutional protocols) to achieve a comprehensive risk assessment. The ROSE rule is best viewed as one component of a structured syncope evaluation rather than a standalone disposition tool.

Prognosis and Outcomes

The prognostic implications of the ROSE rule classification extend beyond the 30-day outcome window. Patients classified as high risk by BRACES criteria have elevated rates of cardiovascular events, recurrent syncope, and all-cause mortality over longer follow-up periods, reflecting the chronic nature of the underlying conditions detected by the criteria (heart failure, structural heart disease, chronic anemia, GI malignancy).

Among low-risk patients (no BRACES criteria), the 30-day serious adverse outcome rate in the validation cohort was 1.5%, and the vast majority of these outcomes were self-limited or manageable in the outpatient setting. Long-term prognosis for low-risk syncope patients is generally favorable, with outcomes approaching those of the general population when no underlying cardiac or hemorrhagic pathology is identified.

For high-risk patients, prognosis depends heavily on the underlying diagnosis identified during the subsequent workup. Arrhythmic syncope managed with pacemaker or ICD implantation carries a good prognosis when appropriately treated. Syncope from acute coronary syndrome or pulmonary embolism carries the prognosis of the underlying condition. Syncope from GI hemorrhage depends on the source and severity of bleeding and the patient's overall comorbidity burden. The ROSE rule's value lies in identifying these patients at the time of their ED presentation, before the specific diagnosis is established, enabling timely investigation and treatment initiation.