Applying the Boston Syncope Criteria to Near Syncope

The Journal of Emergency Medicine, Vol. 43, No. 6, pp. 958–963, 2012 Copyright Ó 2012 Published by Elsevier Inc. Printed in the USA 0736-4679/$ - see front matter

doi:10.1016/j.jemermed.2012.01.043

Original Contributions

APPLYING THE BOSTON SYNCOPE CRITERIA TO NEAR SYNCOPE Shamai A. Grossman, MD, MS, Matthew Babineau, MD, Laura Burke, MD, Adarsh Kancharla, MD, Lawrence Mottley, MD, Andrea Nencioni, MD, and Nathan I. Shapiro, MD, MPH Department of Emergency Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts Reprint Address: Shamai A. Grossman, MD, MS, Department of Emergency Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215

, Abstract—Background: We recently demonstrated that near-syncope patients are as likely as syncope patients to experience adverse outcomes. The Boston Syncope Criteria (BSC) identify patients with syncope unlikely to have adverse outcomes and reduce hospitalizations. It is unclear whether these guidelines could reduce hospitalization in near syncope as well. Objective: To determine if BSC accurately predict which near-syncope patients require hospitalization. Methods: A prospective observational study enrolled from August 2007 to October 2008 consecutive emergency department (ED) patients (aged > 18 years) with near syncope. BSC were first employed assuming that any patient with risk factors for adverse outcomes should be admitted, and then utilized using a modified rule: if the etiology of near syncope is dehydration or vasovagal, and ED work-up is normal, patients may be discharged even with risk factors. Outcomes were identified by chart review and 30-day follow-up calls. Results: Of 244 patients with near syncope, 111 were admitted, with 49 adverse outcomes. No adverse outcomes occurred among discharged patients. If BSC had been followed strictly, another 41 patients with risk factors would have been admitted and 34 discharged, a 3% increase in admission rate. However, using the modified criteria, only 68 patients would have required admission, a 38% reduction in admission, with no missed adverse outcomes on follow-up. Conclusion: Although near-syncope patients may have risk factors for adverse outcomes similar to those with syncope,

if the etiology of near syncope is dehydration or vasovagal, and ED work-up is normal, these patients may be discharged even with risk factors. Ó 2012 Published by Elsevier Inc. , Keywords—near syncope; risk factors; hospitalization; adverse outcomes

INTRODUCTION Although the literature describing syncope is extensive, minimal data are available regarding the management of near syncope. Near syncope is often excluded from syncope studies or excluded due to difficulty in characterizing near syncope as well as a lack of uniform terminology (1–3). Other studies, in contrast, have not differentiated between syncope and near syncope (4–7). It has been postulated that near syncope is associated with fewer comorbidities and perhaps should be considered less ominous (1). However, we have recently demonstrated that if a uniform definition of near syncope is used, patients with near syncope are as likely as patients with syncope to experience adverse outcomes (1). Syncope accounts for approximately 1–3% of emergency department (ED) visits and up to 6% of all hospital admissions across the United States (8,9). Hospitalization for syncope has been estimated at $5300 per stay for a total cost of over $2 billion per year nationally (8–14). As near syncope is often excluded or bundled together with syncope data, the true incidence and cost per

This work was presented at the Society for Academic Emergency Medicine National Meeting, Phoenix, AZ, June 2010; and the Society for Academic Emergency Medicine New England Regional Meeting; Shrewsbury, MA, April 2010.

RECEIVED: 8 May 2011; FINAL SUBMISSION RECEIVED: 26 October 2011; ACCEPTED: 22 January 2012 958

Boston Syncope Criteria and Near Syncope

hospitalization of near syncope is difficult to know and can only be estimated based on the outcome of syncope patients. In an environment of soaring health care costs and dwindling resources, the need for evidence-based criteria for hospitalization decision-making has become increasingly important (11). The Boston Syncope Criteria and modified Boston Syncope Criteria were designed to identify patients with syncope unlikely to have adverse outcomes and reduce hospital admission (2,15). These criteria, as part of a clinical pathway, were able to effectively reduce hospital admissions without adverse events (2,15). It is unclear whether these guidelines could reduce hospital admission of patients with near syncope. Given that patients with near syncope are as likely as patients with syncope to experience adverse outcomes, the objective of this study was to determine whether predefined decision criteria to reduce admission could accurately predict which patients with near syncope require hospitalization. METHODS

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heart disease by history or physical examination; 5) Family history of sudden death; 6) Persistent abnormal vital signs in the ED; 7) Volume depletion such as persistent dehydration, gastrointestinal bleeding, or hematocrit < 30; and 8) Primary central nervous system event. The criteria suggest that patients with risk factors should be admitted, whereas patients without risk factors should be safe for discharge. The modified Boston Syncope Criteria state that if syncope is clearly dehydration or vasovagal in etiology and the ED work-up is otherwise normal, then these patients may be discharged even with risk factors. This was an observational study and the criteria were not used to modify treatment. Using a standardized definition for near syncope, we gathered outcome data in patients found to have this complaint and then applied the Boston Syncope Criteria hypothetically to this patient population. Although the study did not mandate testing, all patients had a complete history, physical examination, and electrocardiogram performed as part of routine care. Patients were admitted to the hospital solely at the discretion of the treating physician.

Study Design Key Outcome Measures We conducted a prospective, observational, cohort study of consecutive patients presenting with near syncope between November 2007 and August 2008. This design was similar to the design used when studying the syncope cohort (2). Institutional review board approval was received before initiation of the study, with waiver of informed consent. Study Setting and Population All patients presenting consecutively to the ED of a large urban teaching hospital with an annual ED census of 55,000 visits were eligible for enrollment. Inclusion criteria included age 18 years or older and documented near syncope. Near syncope was defined in keeping with Scharenbrock’s description of near syncope, as an episode in which the patient felt he might lose consciousness, but did not actually pass out when presenting to the ED (16). Exclusion criteria were persistent altered mental status, alcohol- or illicit drug-related near loss/ loss of consciousness, seizure, hypoglycemia, or near loss/loss of consciousness caused by head trauma. Interventions The Boston Syncope Criteria were developed and validated a priori using evidence-based criteria to identify patients at risk for an adverse outcome or critical intervention if they had any of eight symptom categories (Table 1). These criteria can be categorized as follows: 1) Signs and symptoms of an acute coronary syndrome; 2) Signs of conduction disease; 3) Worrisome cardiac history; 4) Valvular

The primary outcome was an adverse outcome or a critical intervention noted during the ED stay, hospitalization, or upon follow-up telephone call within 30 days after the initial visit. Adverse outcome was defined a priori as: death, cardiac arrest, pulmonary embolus, stroke, severe infection/sepsis, ventricular dysrhythmia, atrial dysrhythmia (including supraventricular tachycardia and atrial fibrillation with rapid ventricular response), intracranial bleed, hemorrhage, myocardial infarction, congestive heart failure, acute renal failure, or life-threatening sequelae of syncope (i.e., rhabdomyolysis, long bone or cervical spine fractures). Critical intervention was defined as implantable/ implantable cardioverter defibrillator placement, percutaneous coronary intervention or surgery, cardiopulmonary resuscitation (CPR), alterations in anti-dysrhythmic therapy, endoscopy with intervention, blood transfusion, or correction of carotid stenosis. All enrolled patients had at least one episode of near syncope meeting the above definition to be eligible for enrollment. All adverse outcomes or clinical interventions, such as CPR, stroke, or cardiac arrest, were noted after spontaneous recovery from the initial nearsyncope episode. Outcomes were determined by inpatient diagnosis, 30-day follow-up phone call, and subsequent medical record review. Study Protocol A trained research assistant prospectively screened patients presenting to the ED with a chief complaint of

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S. A. Grossman et al.

Table 1. The Boston Syncope Criteria: If a Patient Has a Risk Factor, He/She Should be Admitted; Otherwise, the Criteria Advise Discharge from the ED I. Signs and symptoms of acute coronary syndrome 1. Complaint of chest pain of possible cardiac origin 2. Ischemic ECG changes (ST elevation or deep [> 0.1 mV] ST depression) 3. Other ECG changes VT, VF, SVT, rapid atrial fibrillation or new (or not known to be old) STT wave change 4. Complaint of shortness of breath II. Signs of conduction disease 13. Multiple syncopal episodes within the last 6 months 14. Rapid heart beat by patient history 15. Syncope during exercise 16. QT interval > 500 ms 17. Second- or third-degree heart block or intraventricular block III. Worrisome cardiac history 5. History of CAD, including deep q waves, hypertrophic or dilatated cardiomyopathy 6. History of congestive heart failure or LV dysfunction 7. History of ventricular tachycardia, ventricular fibrillation 8. History of pacemaker 9. History of ICD 10. Prehospital use of anti-dysrhythmic medication excluding beta blockers or calcium channel blockers 11. Valvular heart disease noted in history or on ED examination IV. Family history of sudden death 11. Family history (first-degree relative) with sudden death, HOCM, Brugada syndrome, or long-QT syndrome V. Volume depletion 18. Gastrointestinal bleeding by hemoccult or history 19. Hematocrit < 30 20. Dehydration not corrected in the ED per treating physician discretion VI. Persistent (> 15 min) abnormal vital signs in the ED without the need of concurrent interventions such as oxygen, pressors, temporary pacemakers 21. Respiratory rate > 24 breaths/min 22. O2 saturation < 90 23. Sinus rate < 50 or sinus rate > 100 24. Blood pressure < 90 mm Hg VII. CNS 25. Primary CNS event (i.e., SAH, stroke) ED = emergency department; ECG = electrocardiogram; VT = ventricular tachycardia; VF = ventricular fibrillation; SVT = supraventricular tachycardia; CAD = coronary artery disease; ICD = implantable cardioverter defibrillator; HOCM = hypertrophic cardiomyopathy; CNS = central nervous system; SAH = subarachnoid hemorrhage.

near and pre-syncope, syncope, falls, dizziness, passing out, loss of consciousness, hypotension, palpitations, weakness, ataxia, lightheadedness, blackouts, lethargy, fatigue, palpitations, dehydration, feeling poorly, and feeling unwell. A similar screening process was conducted in the syncope cohort as previously reported (2). Patients were brought to the attention of the physician caring for that patient. The treating physician determined patient eligibility. Questionnaires about near-syncope characteristics were completed either on initial ED evaluation or shortly afterward. A research assistant also reviewed daily patient logs to ensure completion of documentation and capture potential missed patients. At the conclusion of the ED work-up, investigators assigned patients to either the vasovagal and dehydration group or other etiology group based on the data accumulated during their ED stay. The final outcome status was assigned by a reviewer who was blinded to the status of the subject’s classification according to the decision rule. Criteria were not used in patient care decisions. A study investigator or trained research assistant carried out follow-up telephone calls with a structured follow-up form and medical record review at 30 days

after initial presentation to the ED to determine whether the subject had a serious outcome or critical intervention either in the hospital or after discharge. Data Analysis The results are reported as point estimates along with the operating characteristics of the rules. Included are p values with 95% confidence intervals. Near-syncope outcomes and admission rates were compared with hypothetical admission rates achieved when utilizing the Boston Syncope Criteria and then the modified Boston Syncope Criteria, utilizing chi-squared. RESULTS From October 2007 until August 2008, 1870 patients were screened for a complaint of near syncope. Two hundred forty-four patients met the study definition of near syncope; 61% were female; the average age was 56 years, SD 6 21. There were a total of 111 admissions with 49 adverse outcomes or critical interventions. Nine of theses patients were admitted to the ED observation unit; none of these

Boston Syncope Criteria and Near Syncope Table 2. Demographics of Modified Criteria Positive and Modified Criteria Negative Patients

Age Gender CAD CHF or LV dysfunction VT/VF Pacemaker Defibrillator Dysrhythmic therapy Fm Hx sudden death Valvular heart disease

Modified Criteria Positive

Modified Criteria Negative

68.6 23% Female 31% 23% 0 0 0 0 0 0

56.3 74% Female 24% 9% 2% 0 4% 9% 2% 7%

CAD = coronary artery disease; CHF = congestive heart failure; LV = left ventricle; VT = ventricular tachycardia; VF = ventricular fibrillation; Fm Hx = family history.

patients had adverse outcomes. Furthermore, no adverse outcomes were found in patients discharged home directly from the ED. Two patients were lost to follow-up analysis. If the Boston Syncope Criteria had been followed strictly, another 41 patients with risk factors for adverse outcomes would have been admitted and 34 discharged, resulting in a 3% increase in admission rate (p = 0.3). However, using the modified Boston Syncope Criteria, only 68 patients would have required admission, resulting in a 28% admission rate or 38% reduction in admission, with no missed adverse outcomes on 30-day follow-up (p = 0.0001); see Table 2 for demographics. DISCUSSION Based on our data, near-syncope patients seem safe for discharge utilizing the Boston Syncope Criteria. However, in our study we also found that near-syncope patients were less likely to be admitted than syncope patients. Therefore if Boston Syncope Criteria were followed strictly, admission rates would have been the same or slightly higher. Previously, we found that ED patients with near syncope are as likely as patients with syncope to experience adverse outcomes and clinical interventions (1). We believe that emergency physicians should treat near syncope with the same vigilance they apply to syncope. Yet, we have found that clinicians seem to be more willing to send patients home with near syncope than patients with syncope (1). Nevertheless, these near-syncope patients who are sent home have not been found to have adverse outcomes on follow-up. This lower baseline admission rate for near-syncopal patients likely reflects a perception among practitioners that near syncope is less ominous than syncope, or that sick near-syncope patients are more easily identified in the ED than syncopal patients. It is possible that practitioners in our ED may have had a bias in their decision-making process, as the Boston Syncope Criteria are now utilized as the standard

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admitting guideline for syncope in our ED and they may have already applied these criteria to near-syncope patients in their practice despite a lack of previously published evidence supporting their equivalence in outcomes. Our data also suggest that the modified Boston Syncope Criteria may be very useful in near-syncope patients. Although near-syncope patients may have risk factors for adverse outcomes similar to those with syncope, if the etiology of near syncope is clearly dehydration or vasovagal, and the ED work-up is otherwise normal, then these patients, like syncope patients, may be able to be discharged even with risk factors for adverse outcome. Limitations Although the principal investigator reviewed each case identified by the research assistant to make sure each patient met study criteria, inter-rater reliability was not measured. In addition, this was a single-institution study and may suffer from a lack of generalizability. Therefore, we may be unable to apply these results without external validation. The modified Boston Syncope Criteria include 25 risk factors, which is a large number to remember. Nevertheless, they are already in use throughout EDs in the United States and abroad, and modifying them to focus on two of the most common presentations for nearsyncope and syncope patients should only enhance their usability. Lastly, the major limitation of the proposed rule is that prospective validation has not been implemented in the near-syncope population, and a prospective interventional trial is needed to confirm safety and efficacy. CONCLUSIONS Near-syncope patients may potentially be safely discharged utilizing the Boston Syncope criteria. Although near-syncope patients may have risk factors for adverse outcomes similar to those with syncope, if the etiology of near syncope is clearly dehydration or vasovagal, and the ED work-up is otherwise normal, then these patients, like syncope patients, might be discharged even with risk factors for adverse outcome. A prospective validation study applying the modified Boston Syncope Criteria to near syncope in real time is needed to confirm safety and efficacy. REFERENCES 1. Grossman SA, Babineau M, Burke L, et al. Do outcomes of near syncope parallel syncope? Am J Emerg Med 2012;30:203–6. 2. Grossman SA, Fischer C, Lipsitz LA, et al. Predicting adverse outcomes in syncope. J Emerg Med 2007;33:233–9. 3. Martin TP, Hanusa BH, Kapoor WN. Risk stratification of patients with syncope. Ann Emerg Med 1997;29:459–66. 4. Quinn JV, Stiell IG, McDermott DA, Sellers KL, Kohn MA, Wells GA. Derivation of the San Francisco Syncope Rule to predict patients with short-term serious outcomes. Ann Emerg Med 2004; 43:224–32.

962 5. von zur Muhlen F, Quan W, D’Agate DJ, et al. A study of carotid sinus massage and head-up tilt table testing in patients with syncope and near-syncope. J Invasive Cardiol 2002;14:477–82. 6. Natarajan B, Nikore V. Syncope and near syncope in competitive athletes. Curr Sports Med Rep 2006;5:300–6. 7. Militianu A, Salacata A, Seibert K, et al. Implantable cardioverter defibrillator utilization among device recipients presenting exclusively with syncope or near-syncope. J Cardiovasc Electrophysiol 1997;8:1087–97. 8. Kapoor WN. Evaluation and outcome of patients with syncope. Medicine 1990;69:160–74. 9. Sun BC, Emond JA, Camargo CA Jr. Direct medical costs of syncope-related hospitalizations in the United States. Am J Cardiol 2005;95:668–71. 10. Beth Israel Deaconess Medical Center Institutional Review. October 1, 2001–January 31, 2002. Boston, MA: Beth Israel Deaconess Medical Center.

S. A. Grossman et al. 11. Nyman JA, Krahn AD, Bland PC, Griffiths S, Manda. The costs of recurrent syncope of unknown origin in elderly patients. Pacing Clin Electrophysiol 1999;22:1386–94. 12. Kapoor WN. Evaluation and management of the Patient with syncope. JAMA 1992;268:2553–60. 13. Gallagher EJ. Hospitalization for fainting: high stakes, low yield. Ann Emerg Med 1997;29:540–2. 14. Day SC, Cook EF, Funkenstein H, Goldman L. Evaluation and outcome of emergency room patients with transient loss of consciousness. Am J Med 1982;73:15–23. 15. Grossman SA, Bar JL, Fischer C, et al. Reducing admissions utilizing the Boston Syncope Criteria. J Emerg Med 2011 Mar 19. [Epub ahead of print]. 16. Scharenbrock CG, Buggs AM, Furgerson JL, Manthey DE. A prospective evaluation of near syncope and syncope in the elderly. Acad Emerg Med 1999;5:532.

Boston Syncope Criteria and Near Syncope

ARTICLE SUMMARY 1. Why is this topic important? In an environment of soaring health care costs and dwindling resources, the need for evidence-based criteria for hospitalization decision-making has become increasingly important. The Boston Syncope Criteria and modified Boston Syncope Criteria, as part of a clinical pathway, were able to effectively reduce hospital admissions without adverse events, but it is unclear whether these guidelines could similarly reduce hospitalization of patients with near syncope, potentially saving substantial health care resources. 2. What does this study attempt to show? The purpose of this study was to determine whether predefined decision criteria to reduce admission (The Boston Syncope Criteria) could accurately predict which patients with near syncope require hospitalization. 3. What are the key findings? If the Boston Syncope Criteria had been followed strictly, these criteria would not have made a significant impact on rate of hospitalization in near-syncope patients (p = 0.3). However, using the modified Boston Syncope Criteria potentially would have resulted in a 38% reduction in admission for this patient population with no missed adverse outcomes on 30-day follow-up (p = 0.0001). 4. How is patient care impacted? Although near-syncope patients may have risk factors for adverse outcomes similar to those with syncope, if the etiology of near syncope is clearly dehydration or vasovagal, and the ED work-up is otherwise normal, then these patients, like syncope patients, might be discharged even with risk factors for adverse outcome.

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