near syncope parallel syn”>American Journal of Emergency Medicine (2012) 30, 203-206

Brief Report

Do outcomes of near syncope parallel syncope?^?

Shamai A. Grossman MD, MS?, Mathew Babineau MD, Laura Burke MD, Adarsh Kancharla MD, Lawrence Mottley MD,

Andrea Nencioni MD, Nathan I. Shapiro MD, MPH

Division of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA

Received 23 June 2010; revised 1 November 2010; accepted 2 November 2010

Abstract

Background: Limited information on the evaluation of emergency department (ED) patients complaining of “near syncope” exists. Multiple studies of syncope exclude near syncope claiming near syncope is poorly defined and its definition is nonuniform.

Objective: The aim of this study was to determine the incidence of critical interventions or adverse outcomes associated with near syncope and compare these outcomes with syncope.

Methods: Prospective, observational study enrolling (August 2007-October 2008) consecutive ED patients (age, >=18 years) presenting with near syncope was conducted. Near syncope was defined as an episode in which the patient felt they might lose consciousness but did not. Critical intervention/adverse outcome was defined as hemorrhage, cardiac ischemia/intervention, alteration in antidysrhythmics, pacemaker/defibrillator placement, sepsis, stroke, death, dysrhythmia, sepsis, pulmonary embolus, or carotid stenosis. Primary outcome was an adverse outcome or critical intervention in hospital or less than 30 days. Near syncope and syncope outcomes and admission rates were compared using the ?² test.

Results: After 1870 patients were screened, 244 met the study definition. Of the 244 patients, follow-up was achieved in 242 (99%). Emergency department hospitalization or 30-day adverse outcomes occurred in 49 (20%) of 244 compared with 68 (23%) of 293 of Patients with syncope (P = .40). The most common adverse outcomes/critical interventions were hemorrhage (n = 6), bradydysrhythmia (n = 6), alteration in antidysrhythmics (n = 6), and sepsis (n = 10). Of patients with near syncope, 49% were admitted compared with 69% with syncope (P = .001).

Conclusion: Patients with near syncope are as likely those with syncope to experience critical interventions or adverse outcomes; however, near-syncope patients are less likely to be admitted. Given similar risk of adverse outcomes for near syncope and syncope, future studies are warranted to improve the treatment of ED patients with near syncope.

(C) 2012

Introduction

^? Prior presentations: Society for Academic Emergency Medicine National Meeting, New Orleans, LA, May 2009, and Society for Academic Emergency Medicine New England Regional Meeting, Shrewsbury, MA, April 2009.

* Corresponding author. Tel.: +1 617 754 2331; fax: +1 617 754 2350.

E-mail address: [email protected] (S.A. Grossman).

Limited information on the evaluation of near syncope is available. Although syncope accounts for approximately 1% to 3% of all emergency department (ED) visits and up to 6% of all hospital admissions nationwide [1,2], one would think that it would be more likely to almost pass out than to actually pass out. However, the true incidence of near

0735-6757/$ - see front matter (C) 2012 doi:10.1016/j.ajem.2010.11.001

204 S.A. Grossman et al.

syncope is undefined. The cost of care per hospital admission for syncope has been estimated at roughly $5300 per stay for a Total cost of more than $2 billion per year nationally [1-7]. One could also hypothesize that near syncope should be less costly, because patients who do not actually lose conscious- ness would be less likely to be admitted and would be associated with fewer comorbidities.

This lack of data is likely related to the difficulty in characterizing near syncope as well as a lack of uniform terminology. Near syncope may be confused with presyncope, or less descriptive complaints such as lightheadedness dizziness, weakness, lethargy, fatigue, and feeling poorly or unwell. Multiple recent studies of syncope exclude near syncope claiming near syncope is poorly defined and its definition is nonuniform [1,8-10]. Other studies, instead, have not differentiated between syncope and near syncope [11-14]. The mechanisms of syncope and near syncope, theoret- ically, should be similar, namely, as Kapoor notes, “a sudden decrease or brief cessation of cerebral blood flow” [15]. The ultimate difference in outcome, that is, whether there, in fact, was loss of coconsciousness or not, would likely depend on the amount of time involved in loss of cerebral blood flow

and the patient’s underlying medical conditions.

The scarce data available suggest that the incidence of serious etiologies may be significantly higher in patients with near syncope than in patients with syncope [16]. The objectives of this study are to determine, with a well-defined, uniform definition of near syncope, the incidence of critical interventions or adverse outcomes associated with near syncope and to compare these outcomes with the outcomes of patients with true syncope.

Methods

Study design

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 [8]. Institutional review board approval was received before initiation of the study, with waiver of informed consent

Study setting and population

As in the syncope cohort, 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 or older and documented near syncope. Near syncope was defined in accordance with the description of near syncope by Scharenbrock et al [16], as an episode in which the patient felt he might lose consciousness but did not actually pass out when presenting to the ED. Syncope, in

turn, was defined as a sudden and transient (less than 5 minutes) episode of loss of consciousness resulting in spontaneous recovery without resuscitation measures. Exclusion criteria in both cohorts 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

This was an observational study, so there was no intervention. We used a standardized definition for near syncope and then gathered outcome data in patients found to have this complaint when seeking medical attention in an ED. Although the study did not mandate testing, all patients had a complete history, physical examination, and electrocardiogram performed as part of routine care.

Key outcome measures

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 following the initial visit. Adverse outcome was defined a priori as follows: death, cardiac arrest, pulmonary embolus, stroke, severe infection/sepsis, ventricular arrhythmia, atrial arrhythmia (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 (ie, rhabdomyolysis and long bone or cervical spine fractures). Critical intervention was defined as pacemaker/ Implantable cardioverter-defibrillator placement, percutane- ous coronary intervention or surgery, cardiopulmonary resuscitation, alterations in antidysrhythmic therapy, endos- copy with intervention, blood transfusion, or correction of carotid stenosis.

All enrolled patients had at least 1 episode of near syncope meeting the above definition to be eligible for enrollment. All adverse outcomes or clinical interventions, such as cardiopulmonary resuscitation, stroke, or cardiac arrest, were noted following spontaneous recovery from the initial near-syncope episode. Outcomes were determined by inpatient diagnosis, 30-day follow-up telephone call, and subsequent medical record review.

Study protocol

A trained research assistant prospectively screened patients with complaints of near syncope presenting to the ED with a chief complaint of near and presyncope, syncope, falls, dizziness, passing out, loss of consciousness, hypoten- sion, palpitations, weakness, ataxia, lightheadedness, black- outs, lethargy, fatigue, palpitations, dehydration, feeling poorly, and feeling unwell. A similar screening process was conducted in the syncope cohort as previously reported [8].

Near syncope outcomes 205

Table 1 Demographics and comorbidities in near-syncope and syncope patients

Comorbidity	Near syncope (n = 244), n (%, 95% confidence interval)	Syncope (n = 293), n (%, 95% confidence interval)
Admitted to hospital	120 (49, 43%-55%)	202 (69, 63%-74%)
Age, mean +- SD (y)	56.2 +- 21	57.8 +- 24.2
Sex (% female)	73 (61, 55%-67%)	199 (58, 52%-64%)
Chest pain	22 (9, 6%-13%)	3 (8, 5%-21%)
Ischemic electrocardiogram (ECG)	5 (2, 1%-5%)	6 (2, 1%-5%)
Abnormal heart rhythm or new ECG changes	9 (16, 12%-21%)	44 (15, 11%-20%)
Shortness of breath	22 (9, 6%-13%)	18 (6, 4%-10%)
history of coronary artery disease	32 (3, 9%-18%)	59 (20, 16%-25%)
history of heart failure or left ventricular dysfunction	12 (5, 3%-8%)	15 (5, 3%-8%)
Ventricular tachycardia	2 (1, 0.2%-3%)	1 (0.3, 0.1%-2%)
History of pacemaker	2 (1, 0.2-3%	9 (3% 2%-6%)
Implantable cardioverter-defibrillator	5 (2% 1%-5%)	6 (2% 1%-5%)
Antidysrhythmic medication	15 (6, 4%-10%)	39 (13, 10%-17%)
Family history of sudden death	2 (1, 0.2%-3%)	6 (2, 1%-5%)
Significant heart murmur	5 (2, 1%-5%)	9 (3, 2%-6%)
Recurrent near syncope/syncope	5 (2, 1%-5%)	35 (12, 9%-16%0
Palpitations		6 (2, 1%-5%)
Syncope during exercise		1 (0.3, 0.1%-2%)
QT interval, N500 ms
heart block		6 (2, 1%-5%)
Gastrointestinal bleeding in the ED	2 (1, 0.2%-3%)	6 (2, 1%-5%)
Profound dehydration	10 (4, 2%-7%)	3 (1, 0.4%-3%)
Intracranial hemorrhage or stroke		2 (0.7, 0.2%-2%)

Patients were brought to the attention of the physician caring for that patient. The treating physician determined patient eligibility. Both attending and resident physicians were instructed before study initiation as to the details of enrollment criteria. Questionnaires about near-syncope or syncope characteristics were completed either on initial

Table 2 Primary adverse outcomes and interventions following ED presentation with near syncope

ED evaluation or shortly afterward. A research assistant also reviewed daily patient logs to ensure completion of documentation and document missed patients.

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 following initial presentation

Adverse outcome/critical intervention	In ED or hospital (n = 47)	Within 30 days of ED visit (n = 2)	Total number (n = 49)
Sepsis	10 (21, 12%-35%)		10	(20, 12%-34%)
Bradydysrhythmia Treatment	6 (13, 6%-25%)		6	(12, 6%-24%)
Alteration in dysrhythmics	5 (11, 5%-23%)	1 (50, 9%-90%)	6	(12, 6%-24%)
Gastrointestinal bleeding	5 (11, 5%-23%)	1 (50, 9%-90%)	6	(12, 6%-24%)
Acute renal failure	5 (11, 5%-23%)		5	(10, 5%-22%)
Ventricular-dysrhythmia treatment	3 (6, 2%-17%)		3	(6, 2%-17%)
Atrial-dysrhythmia treatment	3 (6, 2%-17%)		3	(6, 2%-17%)
Pacemaker placement or adjustment	3 (6, 2%-17%)		3	(6, 2%-17%)
Carotid stenosis and endarterectomy	1 (2, 0.5%-11%)		1	(2, 0.4%-10%)
Congestive heart failure	1 (2, 0.5%-11%)		1	(2, 0.4%-10%)
Myocardial infarction	1 (2, 0.5%-11%)		1	(2, 0.4%-10%)
Valvular disease management	1 (2, 0.5%-11%)		1	(2, 0.4%-10%)
Deep venous thrombosis/pulmonary embolus	1 (2, 0.5%-11%)		1	(2, 0.4%-10%)
Small bowel obstruction requiring resection	1 (2, 0.5%-11%)		1	(2, 0.4%-10%)
Stroke	1 (2, 0.5%-11%)		1	(2, 0.4%-10%)
If patients had more than 1 event, only the adverse event noted on discharge as the primary diagnosis was listed in the table so that if a patient was septic and subsequently had a small myocardial infarction, the adverse event listed would be sepsis.

206 S.A. Grossman et al.

to the ED to determine whether the subject had a serious outcome or critical intervention either in 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 previously collected and published syncope outcomes using the ?2 test [8].

Results

There were 1870 patients screened for a complaint of near syncope, whereas 244 patients ultimately met the study definition of near syncope. Sixty-one percent were female. The average (SD) age was 56 (21) years (Table 1). The 4 most common adverse outcomes and critical interventions were treatment of gastrointestinal bleeding, bradydysrhyth- mias, sepsis, and alteration in antidysrhythmics (Table 2).

Adverse outcomes and critical interventions occurred in 49 (20%) of 244 patients with near syncope compared with 68 (23%) of 293 of patients with true syncope (P = .40). No patient discharged home from the ED was subsequently found to have adverse outcomes on 30-day follow-up. Two patients were lost to follow-up analysis.

Forty-nine percent (120/244) of patients with near syncope were admitted compared with 69% (202/293) of patients with syncope (P = .001) (Table 1).

Discussion

Limitations of the study include the difficulty in establishing a universally accepted definition of near syncope. This is particularly challenging given the existing large array of terms for near syncope currently in use such as presyncope, or almost fainting. Although the principal investigator reviewed each case identified by the research assistant to make sure each patient met the study criteria, interrater reliability was not measured. Also, the lack of a uniform assessment at the time of visit is a limitation. 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.

Conclusions

In our study, patients with near syncope were as likely as patients with syncope to experience adverse outcomes. However, near-syncope patients were less likely to be admitted. Given a similar risk of adverse outcome for near syncope and syncope, future studies of near syncope should be conducted to improve the treatment of patients presenting to the ED with near syncope.

References

1. Kapoor WN. Evaluation and outcome of patients with syncope. Medicine 1990;69:160-74.
2. Sun BC, Emond JA, Camargo Jr CA. Direct Medical costs of syncope- related hospitalizations in the United States. Am J Cardiol 2005;95: 668-71.
3. Beth Israel Deaconess Medical Center Institutional Review. 10/01/01- 1/31/02.
4. Nyman JA, Krahn AD, Bland PC, Griffiths S, Manda S. The costs of recurrent syncope of unknown origin in elderly patients. Pacing Clin Electrophysiol 1999;138694:22.
5. Kapoor WN. Evaluation and management of the patient with syncope.

JAMA 1992;268:2553-60.

1. Gallagher EJ. Hospitalization for fainting: high stakes, low yield. Ann Emerg Med 1997;29:540-2.
2. 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.
3. Grossman SA, Fischer C, Lipsitz LA, Mottley L, Sands K, Thompson S, et al. Predicting adverse outcomes in syncope. J Emerg Med 2007;33:233.
4. Elesber H. Evaluation of the safety and cost-effectiveness of the ACEP clinical policy in regards to admission of the syncopal patient. Acad Emerg Med 2002.
5. Martin TP, Hanusa BH, Kapoor WN. Risk stratification of patients with syncope. Ann Emerg Med 1997;29:459-66.
6. 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.
7. 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.
8. Natarajan B, Nikore V. Syncope and near syncope in competitive athletes. Curr Sports Med Rep 2006;5:300-6.
9. 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.
10. Kapoor WN. Syncope. N Engl J Med 2000;343:1856-62.
11. 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.