Incidence, etiology and predictors of adverse outcomes in 43,315 patients presenting to the Emergency Department with syncope: An international meta-analysis

Published:December 22, 2011DOI:



      Syncope remains challenging for Emergency Department (ED) physicians due to difficulties in assessing the risk of future adverse outcomes. The aim of this meta-analysis is to establish the incidence and etiology of adverse outcomes as well as the predictors, in patients presenting with syncope to the ED.


      A systematic electronic literature review was performed looking for eligible studies published between 1990 and 2010. Studies reporting multivariate predictors of adverse outcomes in patients presenting with syncope to the ED were included and pooled, when appropriate, using a random-effect method. Adverse events were defined as ‘incidence of death, or of hospitalization and interventional procedures because of arrhythmias, ischemic heart disease or valvular heart disease’.


      11 studies were included. Pooled analysis showed 42% (CI 95%; 32–52) of patients were admitted to hospital. Risk of death was 4.4% (CI 95%; 3.1–5.1) and 1.1% (CI 95%; 0.7–1.5) had a cardiovascular etiology. One third of patients were discharged without a diagnosis, while the most frequent diagnosis was ‘situational, orthostatic or vasavagal syncope’ in 29% (CI 95%; 12–47). 10.4% (CI 95%; 7.8–16) was diagnosed with heart disease, the most frequent type being bradyarrhythmia, 4.8% (CI 95%; 2.2–6.4) and tachyarrhythmia 2.6% (CI 95%; 1.1–3.1). Palpitations preceding syncope, exertional syncope, a history consistent of heart failure or ischemic heart disease, and evidence of bleeding were the most powerful predictors of an adverse outcome.


      Syncope carries a high risk of death, mainly related to cardiovascular disease. This large study which has established the most powerful predictors of adverse outcomes, may enable care and resources to be better focused at high risk patients.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to International Journal of Cardiology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Soteriades E.S.
        • Evans J.C.
        • Larson M.G.
        • et al.
        Incidence and prognosis of syncope.
        N Engl J Med. 2002; 347: 878-885
        • Ungar A.
        • Del Rosso A.
        • Giada F.
        • et al.
        Evaluation of Guidelines in Syncope Study 2 Group. Early and late outcome of treated patients referred for syncope to emergency department: the EGSYS 2 follow-up study.
        Eur Heart J. 2010; 31: 2021-2026
        • Kessler C.
        • Tristano J.M.
        • De Lorenzo R.
        The emergency department approach to syncope: evidence-based guidelines and prediction rules.
        Emerg Med Clin North Am. 2010; 28: 487-500
        • Kapoor W.N.
        N Engl J Med. 2000; 343: 1856-1862
        • Obama B.
        Modern health care for all Americans.
        N Engl J Med. 2008; 359: 1537-1541
        • Sun B.C.
        • Emond J.A.
        • Camargo Jr., C.A.
        Direct medical costs of syncope-related hospitalizations in the United States.
        Am J Cardiol. 2005; 95: 668
        • Serrano L.A.
        • Hess E.P.
        • Bellolio M.F.
        • et al.
        Accuracy and quality of clinical decision rules for syncope in the emergency department: a systematic review and meta-analysis.
        Ann Emerg Med. 2010; 56 (e1): 362-373
        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • et al.
        PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
        BMJ. 2009; 339: b2535
        • Moher D.
        • Cook D.J.
        • Eastwood S.
        • et al.
        Improving the quality of reports of meta-analyses of randomised controlled trials: the QUOROM statement. Quality of reporting of meta-analyses.
        Lancet. 1999; 354: 1896-1900
        • Stroup D.F.
        • Berlin J.A.
        • Morton S.C.
        • et al.
        Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis Of Observational Studies in Epidemiology (MOOSE) group.
        JAMA. 2000; 283: 2008-2012
      1. Higgins J.P.T. Green S. Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.2 [updated September 2009]. The Cochrane Collaboration, 2009 (Available from)
        • Wilczynski N.L.
        • Haynes R.B.
        • for the Hedges Team
        Developing optimal search strategies for detecting clinically sound prognostic studies in MEDLINE: an analytic survey.
        BMC Med. 2004; 2: 23
        • McManus R.J.
        • Wilson S.
        • Delaney B.C.
        • et al.
        Review of the usefulness of contacting other experts when conducting a literature search for systematic reviews.
        BMJ. 1998; 317: 1562-1563
        • Chen L.Y.
        • Jahangir A.
        • Decker W.W.
        • et al.
        Score indices for predicting electrophysiologic outcomes in patients with unexplained syncope.
        J Interv Card Electrophysiol. 2005; 14: 99-105
        • Da Costa A.
        • Gulian J.L.
        • Romeyer-Bouchard C.
        • et al.
        Clinical predictors of cardiac events in patients with isolated syncope and negative electrophysiologic study.
        Int J Cardiol. 2006; 109: 28-33
        • Fedorowski A.
        • Burri P.
        • Juul-Möller S.
        • Melander O.
        A dedicated investigation unit improves management of syncopal attacks (Syncope Study of Unselected Population in Malmo–SYSTEMA I).
        Europace. 2010; 12: 1322-1328
        • Pfister R.
        • Hagemeister J.
        • Esser S.
        • Hellmich M.
        • Erdmann E.
        • Schneider C.A.
        NT-pro-BNP for diagnostic and prognostic evaluation in patients hospitalized for syncope.
        Int J Cardiol. 2012 Mar 8; 155: 268-272
        • Haghjoo M.
        • Faghfurian B.
        • Taherpour M.
        • et al.
        Predictors of syncope in patients with hypertrophic cardiomyopathy.
        Pacing Clin Electrophysiol. 2009; 32: 642-647
        • Martin T.P.
        • Hanusa B.H.
        • Kapoor W.N.
        Risk stratification of patients with syncope.
        Ann Emerg Med. 1997; 29: 459-466
        • Colivicchi F.
        • Ammirati F.
        • Melina D.
        • Guido V.
        • Imperoli G.
        • Santini M.
        OESIL (Osservatorio Epidemiologico sulla Sincope nel Lazio) Study Investigators. Development and prospective validation of a risk stratification system for patients with syncope in the emergency department: the OESIL risk score.
        Eur Heart J. 2003; 24: 811-819
        • Costantino G.
        • Perego F.
        • Dipaola F.
        • et al.
        STePS Investigators. Short- and long-term prognosis of syncope, risk factors, and role of hospital admission: results from the STePS (Short-Term Prognosis of Syncope) study.
        J Am Coll Cardiol. 2008; 51: 276-283
        • Del Rosso A.
        • Ungar A.
        • Maggi R.
        • et al.
        Clinical predictors of cardiac syncope at initial evaluation in patients referred urgently to a general hospital: the EGSYS score.
        Heart. 2008; 94: 1620-1626
        • Gabayan G.Z.
        • Derose S.F.
        • Asch S.M.
        • et al.
        Predictors of short-term (seven-day) cardiac outcomes after emergency department visit for syncope.
        Am J Cardiol. 2010; 105: 82-86
        • Oh J.H.
        • Hanusa B.H.
        • Kapoor W.N.
        Do symptoms predict cardiac arrhythmias and mortality in patients with syncope?.
        Arch Intern Med. 1999; 159: 375-380
        • Quinn J.V.
        • Stiell I.G.
        • McDermott D.A.
        • Sellers K.L.
        • Kohn M.A.
        • Wells G.A.
        Derivation of the San Francisco Syncope Rule to predict patients with short-term serious outcomes.
        Ann Emerg Med. 2004; 43: 224-232
        • Reed M.J.
        • Newby D.E.
        • Coull A.J.
        • Prescott R.J.
        • Jacques K.G.
        • Gray A.J.
        The ROSE (risk stratification of syncope in the emergency department) study.
        J Am Coll Cardiol. 2010; 55: 713-721
        • Sarasin F.P.
        • Hanusa B.H.
        • Perneger T.
        • Louis-Simonet M.
        • Rajeswaran A.
        • Kapoor W.N.
        A risk score to predict arrhythmias in patients with unexplained syncope.
        Acad Emerg Med. 2003; 10: 1312-1317
        • Sun B.C.
        • Derose S.F.
        • Liang L.J.
        • et al.
        Predictors of 30-day serious events in older patients with syncope.
        Ann Emerg Med. 2009; 54 (e1-5): 769-778
        • Sun B.C.
        • Hoffman J.R.
        • Mangione C.M.
        • Mower W.R.
        Older age predicts short-term, serious events after syncope.
        J Am Geriatr Soc. 2007; 55: 907-912
        • Suzuki M.
        • Hori S.
        • Nakamura I.
        • Soejima K.
        • Aikawa N.
        Long-term survival of Japanese patients transported to an emergency department because of syncope.
        Ann Emerg Med. 2004; 44: 215-221
        • Brignole M.
        • Ungar A.
        • Casagranda I.
        • et al.
        Syncope Unit Project (SUP) investigators. Prospective multicentre systematic guideline-based management of patients referred to the Syncope Units of general hospitals.
        Europace. 2010; 12: 109-118
        • Moya A.
        • Sutton R.
        • Ammirati F.
        • Task Force for the Diagnosis and Management of Syncope; European Society of Cardiology (ESC); European Heart Rhythm Association (EHRA); Heart Failure Association (HFA); Heart Rhythm Society (HRS)
        Guidelines for the diagnosis and management of syncope (version 2009).
        Eur Heart J. 2009; 30: 2631-2671
        • American College of Emergency Physicians
        Clinical policy: critical issues in the evaluation and management of patients presenting with syncope.
        Ann Emerg Med. 2001; 37: 771-776
        • Agostoni P.
        • Kedhi E.
        • Verheye
        • et al.
        Dissimilar relevance given to diseases by medical literature, and the potential to create biases in the clinical decision-making process: the case of late stent thrombosis.
        Int J Cardiol. 2007 Jan 8; 114: E38-E39
        • Ross J.S.
        • Mulvey G.K.
        • Stauffer B.
        • et al.
        Statistical models and patient predictors of readmission for heart failure: a systematic review.
        Arch Intern Med. 2008; 168: 1371-1386
        • Delise P.
        • Allocca G.
        • Marras E.
        • et al.
        Risk stratification in individuals with the Brugada type 1 ECG pattern without previous cardiac arrest: usefulness of a combined clinical and electrophysiologic approach.
        Eur Heart J. 2011; 32: 169-176
        • Gaita F.
        • Giustetto C.
        • Bianchi F.
        • et al.
        Short QT Syndrome: a familial cause of sudden death.
        Circulation. 2003; 108: 965-970