SYNCOPE
The ACCF/AHA Scientific Statement on Syncope: a document in need of thoughtful revision
Cardiovascular Division, Cardiac Arrhythmia Center, University of Minnesota Medical School, Mail Code 508, 420 Delaware St SE, Minneapolis, MN 55455, USA
Manuscript submitted 26 July 2006. Accepted after revision 22 August 2006.
Corresponding author. Tel: +1 612 625 4401; fax: +1 612 624 4937. E-mail address: bendi001{at}umn.edu
Abstract
The American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) have recently published, in both the Journal of the American College of Cardiology (JACC) and Circulation, a Scientific Statement on the Evaluation of Syncope (‘Statement’). This Scientific Statement was commissioned to provide guidance for clinicians regarding the evaluation of patients who present with ‘syncope’. The Statement was not intended to be a formal set of practice guidelines. However, in the absence of generally accepted practice guidelines in North America, the Statement's potential impact on clinical care may be more far-reaching than expected; it may erroneously be considered to be the authoritative ‘de-facto’ guideline document. This commentary, submitted by a multidisciplinary consortium of more than 60 physicians with expertise in the management of transient loss of consciousness (TLOC), points out that in many respects the ACCF/AHA Syncope Statement fails to address long-standing clinical errors associated with the evaluation of episodes of apparent TLOC, including syncope. If not appropriately revised, the current Statement may lead to both inadequate patient care as well as a potentially damaging legal environment for physicians undertaking evaluation of patients who present with transient loss of consciousness.
Key Words: Syncope, Practice guidelines, Diagnosis, Evaluation, Management
Recently, the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) published, in both Journal of the American College of Cardiology (JACC) and Circulation, a scientific statement on the evaluation of syncope (‘statement’).1
This scientific statement was commissioned to provide guidance for clinicians regarding the evaluation of patients who present with ‘syncope’.
The ACCF/AHA statement was not intended to be a formal set of practice guidelines. Nonetheless, in the absence of formal practice guidelines endorsed by professional societies in North America, the statement's impact on clinical care may be far-reaching. In fact, given its carrying the imprimatur of the ACCF, the AHA, and the Heart Rhythm Society, the statement may be erroneously considered to be the authoritative de facto guideline document.
The Ad Hoc Syncope Consortium is a multidisciplinary group of more than 60 physicians with expertise in the management of patients presenting with transient loss of consciousness (TLOC), including syncope. The consortium formed primarily as a result of its individual members having identified important concerns with the ACCF/AHA syncope statement. Apart from alerting readers to the syncope statement's shortcomings, the consortium's goals are to support thoughtful revision of the syncope statement and to promote development of guidelines for management of patients with TLOC that takes into account the multifaceted nature of the problem. To this end, the Ad Hoc Consortium has published a commentary regarding the syncope statement on Heart.org and a brief letter addressing some of our concerns with the statement in JACC. Circulation has declined publishing any critique of the statement.
In the consortium's opinion, the ACCF/AHA syncope statement does not adequately address many long-standing clinical errors associated with the evaluation of episodes of apparent self-limited TLOC, including syncope. In addition, the statement's messages and conclusions are often imprecise and seem to lack balance. Although, in some instances, our disagreements with the statement's positions may simply reflect honest differences of opinion, there are clear-cut oversights in the statement that deserve attention. Several important shortcomings are highlighted subsequently.
Clinicians need clear, practical, and accurate definitions of syncope and related terminology before they can begin their diagnostic evaluation. The ACCF/AHA statement does not provide accurate definitions. For instance, it is critical in our opinion that a document focusing on the syncope evaluation addresses the fundamental issue, ‘what is syncope?’. The statement's approach is inadequate; it does not establish the distinction between syncope and the broader problem of TLOC.2–4 For the statement to be useful, it must address what syncope is and how it differs from other forms of TLOC (e.g. concussion due to trauma, epileptic seizures due to a primary electrical problem, and apparent TLOC such as in conversion disorders). To be fair, failure to distinguish syncope from other forms of TLOC is an error,5 which is also found in other prominent medical writings.6,7
The absence of clarity regarding the central topic of the statement's interest only serves to aggravate other long-standing misunderstandings. By way of example, the statement itself continues to foster the misconception that ‘vasovagal’ and ‘neurocardiogenic’ syncopes are synonymous. The former is, in fact, a subset of the neurocardiogenic faints (the preferred term being neurally mediated reflex faints 8). This may appear to be a minor point, and certainly elimination of all errors is not a reasonable expectation, but it is indicative of the need for careful and critical review of statements from professional societies prior to publication.
The consequence of imprecise definitions is propagation of unclear thinking among clinicians. The outcome is uncertainty leading to excessive and generally futile overuse of inappropriate medical tests.9–12 The statement missed an opportunity to rectify this major problem; one that leads to unnecessary costs and possible patient harm.
Absence of citations to many published contemporary statements and documents
The ACCF/AHA statement offers as a goal ‘to summarize the data that direct the evaluation of the patient with syncope’. However, the statement fails to cite important recent contributions to the syncope evaluation. Most importantly, the European Society of Cardiology (ESC) Syncope Guideline statements8,13 published in 2001 and revised in 2004 are missing. In this regard, a number of Consortium's members (*) admit a potential conflict of interest, having participated in the ESC guideline development.
Contrary to the preferred current practice in which the best available medical evidence is used to support clinical recommendations, the statement ignores the majority of recently published controlled trials in the field. For instance, although the statement's authors cite three ICD trials14–16 and one drug trial,17 none of which focused primarily on a syncope population per se, they only reference a single non-ICD trial that did enroll true syncope patients.18 Further, the authors failed to cite either of the two major North American pacing trials targeting syncope patients (VPS-1 and VPS-219,20), or the single large beta-blocker trial (POST21,22), or the only trial examining the utility of an organized syncope management unit in a North American hospital (SEEDS23). Moreover, the current statement omits citing any of the several European randomized and/or controlled clinical trials that assessed various aspects of the syncope evaluation, and several of which were published in the North American journals. With the exception of the citation of SAFE-PACE,24 published clinical trials such as EGSYS,25 OESIL,26 OESIL2,27 ISSUE-1,28–30 ISSUE-2,31 VASIS,32,33 SYDIT,34 and SYNPACE35 were not referenced.
It is true that the statement was commissioned to focus on ‘evaluation’ (not on treatment) and apparently had space limitations that may have precluded citing all pertinent literatures. Further, many, but not all, of the missing citations examined aspects of syncope treatment rather than diagnostic evaluation. In contrast, it is impractical to try to divorce evaluation and treatment completely. All of the published studies provide important insights into the optimal evaluation process. Indeed, many of the studies that were cited in the statement were no less treatment-oriented than were the multitude of studies that were omitted.
The rationale for the evaluation of syncope is not solely to provide a mortality risk assessment
According to the statement, the primary ‘purpose of the (syncope) evaluation’ is ‘to determine whether the patient is at increased risk for death’. We agree that mortality risk assessment is a valid concern. However, the vast majority of these patients has disturbing or disabling condition, which is not life threatening, but may diminish quality of life and lead to physical injury.2,6,36–40 Consequently, the rationale for the syncope evaluation should be a more fundamental one, namely, to establish the cause of the patient's symptoms with sufficient confidence to assess prognosis and recommend an effective treatment strategy.8,13,36,37
Appropriate clinical perspective
The statement focuses on the relatively small, albeit important, subset of high-risk patients (at most 20% of those with syncope) who may require treatment with cardiovascular interventions such as implantable cardioverter-defibrillators (ICDs) or pacemakers. However, thoughtful consideration of far more prevalent causes of syncope, namely, those of neurally mediated reflex or orthostatic origin, are hardly addressed.36,37,39–42 These latter conditions account overall for more than half of all syncope cases, although rarely life-threatening can result in substantial morbidity. Furthermore, certain types of faints (e.g. vasovagal syncope and situational faints) are particularly important in children and young adults. The relevance of patient age to the syncope evaluation process (i.e. the likelihood of one or other form of syncope being more or less probable) is inadequately addressed in the statement. The fact that neurally mediated and orthostatic fainting conditions have been the subject of many recent published studies and reviews36,37,40–52 does not exempt the statement from providing practitioners with an appropriate perspective on the problem.
Even regarding ICD and pacemaker therapies, the statement lacks a comprehensive and carefully defined approach. Specifically, the statement does not provide practitioners with sufficient depth of insight into the appropriate circumstances and limitations of ICD or pacemaker utilization in syncope patients. For instance, although ICDs may prevent arrhythmic death, they may not alleviate syncope. This vital aspect of the treatment of the high-risk fainter is a common dilemma in patients with structural heart disease, as well as in individuals with less common conditions such as long QT syndrome and Brugada syndrome. It remains unexplored in the statement.
In the case of syncope patients with normal hearts, the statement underemphasizes the importance of a thorough evaluation. The statement implies that aggressive diagnostic effort is only needed in the most severe (‘malignant’) forms of syncope, where ‘malignant’ is ‘defined as an episode of syncope that occurs with little or no warning and results in significant injury or property damage’. This teaching unfortunately tends to diminish the importance of symptoms in the vast majority of fainters, individuals who we know have substantially reduced quality of life,53 and who may be at future risk of injury, accident, or economic loss because of occupational issues.
The statement should encourage effective diagnostic assessment in all types of syncope patients. Beyond ICDs and pacemakers, clinicians should be made aware of evolving treatment options for vasovagal fainters, or patients with orthostatic hypotension, including those suffering from various dysautonomias.43–51
A revised statement should incorporate a more thoughtful assessment of the important role that medical specialists outside the cardiovascular disease arena play in the evaluation of TLOC/syncope. Neuroscience, internal medicine, paediatrics, and geriatric specialties, among others, contribute daily to the care of patients who present with apparent loss of consciousness spells. Without input from leaders in these fields, recommendations for the syncope evaluation, such as those provided in the ACCF/AHA statement, cannot be considered complete and credible.
In conclusion, we would like to emphasize our concern that the current ACCF/AHA statement may be mistakenly construed as an authoritative text. In the absence of a well-considered set of practice guidelines, the statement could unfortunately become an inappropriate ‘standard’ for all syncope evaluations in the USA and Canada. As such, its current contents may lead to both less than optimal patient care and a potentially damaging legal environment for physicians undertaking the evaluation of patients who present with TLOC. It is clear that development of internationally applicable multidisciplinary formal practice guidelines must receive high priority.
Appendix
Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
Haruhiko Abe
The Second Department of Internal Medicine,University of Occupational and Environmental Health, Yahatanishi, Kitakyushu 807-8555, Japan
Paolo Alboni
Divisione di Cardiologia, Ospedale Civile, Cento, Italy
Dietrich Andresen
Direktor der Klinik für Innere Medizin-Kardiologie/Angiologie/konserv, Intensivmedizin, Vivantes-Klinikum Am Urban/Im Friedrichshain 10 967, Berlin
Felicia B. Axelrod
New York University School of Medicine, Carl Seaman Family Professor of Dysautonomia Treatment and Research, Pediatrics, NYU Medical Center, New York, NY, USA
Eduardo Bennaroch
Department of Neurology, Mayo Medical School, Mayo Clinic, Rochester, MN, USA
Lennart Bergfeldt
Department of Cardiology, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
Jean Jacques Blanc
Departement de Cardiologie, Universite de Brest, Hopital de la Cavale Blanche, CHU de Brest, France
Michele Brignole
Department of Cardiology and Arrhythmologic Centre, Ospedali del Tigullio, 16033 Lavagna, Italy
A. John Camm
St George's Medical School of London, Cranmer Terrace, London, UK
Thomas Chelimsky
Case Western Reserve University, American Academy of Neurology, University Hospitals of Cleveland, Cleveland, OH, USA
Pietro Cortelli
Alma Mater Studiorum-Universita'di Bologna, Dipartimento di Scienze Neurologiche, 40123 Bologna, Italy
J. Gert van Dijk
Department of Neurology and Clinical Neurophysiology, Leiden University Medical Centre, Leiden, The Netherlands
Nynke van Dijk
Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
Murray Esler
Monash University, Melbourne, Australia
Baker Heart Research Institute, Melbourne, Victoria 8008, Australia
Adam Fitzpatrick
Manchester Heart Centre, Royal Infirmary, Manchester, UK
Fetnat Fouad-Tarazi
Department of Cardiology, Cleveland Clinic Foundation, Cleveland, OH, USA
Roy Freeman
Harvard Medical School, Center for Autonomic and Peripheral Nerve Disorders, Beth Israel Deaconess Medical Center, Boston, MA, USA
MaryAnn Goldstein
Pediatric Emergency Medicine, Minneapolis, MN, USA
Blair Grubb
Medical College of Ohio, Toledo, OH, USA
Bengt Herweg
University of South Florida, Tampa, FL, 33606, USA
Max J. Hilz
Department of Neurology, University Erlangen-Nuremberg, Erlangen, Germany
American Academy of Neurology, New York University School of Medicine, New York, NY, USA
Giris Jacob
Rambam Medical Center and Technion IIT, Hiafa, Israel
David Jardine
Christchurch School of Medicine, University of Otago, Christchurch, New Zealand
Jens Jordan
Franz-Volhard Centrum für Klinische Forschung, 13125 Berlin, Germany
Michael J. Joyner
Mayo Clinic, Rochester, MN, USA
Wishwa Kapoor
Department of Internal Medicine, University of Pittsburgh, Pittsburgh, PA, USA
Horacio Kaufmann
Mount Sinai School of Medicine, New York, NY, USA
Rose-Anne Kenny
Institute of Neuroscience, Trinity College, Dublin 2, Ireland
Institute for the Health of the Elderly, University of Newcastle Upon Tyne, Royal,Victoria Infirmary, Newcastle upon Tyne, UK
Andrew Krahn
Arrhythmia Monitoring Unit, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
Chu-Pak Lau
Department of Medicine, Hong Kong University and Queen Mary Hospital, Hong Kong, China
Benjamin D. Levine
Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, TX 75231, USA
Johannes J. van Lieshout
Department of Internal Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
Lewis Lipsitz
Hebrew Senior Life Institute for Aging Research, Boston, MA, USA
Philip Low
Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, USA
Keith G. Lurie
University of Minnesota Medical School and Central Minnesota Heart Center,
Hennepin County Hospital, Minneapolis, MN, USA
St Cloud Hospital, St Cloud Minnesota, USA
Christopher J. Mathias
Neurovascular Medicine Unit, Faculty of Medicine, Imperial College London at St Mary's Hospital, The Queen Elizabeth, The Queen Mother Wing, London W2 1NY, UK
Autonomic Unit, National Hospital for Neurology and Neurosurgery, Queen Square and Institute of Neurology, University College London, London WC1 N 3BG, UK
Angel Moya
Department of Cardiology, Hospital General Vall d'Hebron, 08035 Barcelona, Spain
Brian Olshansky
University of Iowa Medical School, Iowa City, IA, USA
Satish R. Raj
Vanderbilt University, Nashville, TN, USA
Antonio Raviele
Divisione di Cardiologia, Ospedale Umberto I, Mestre-Venice, Italy
Sanjeev Saksena
Robert Wood Johnson Medical School, Millburn, NJ, USA
Francois P. Sarasin
Hopital Cantonal, University of Geneva Medical School, 1211 Geneva 14, Switzerland
Philip J. Saul
Medical University of South Carolina, Charleston, SC, USA
Ronald Schondorf
Department of Neurology McGill University, SMBD Jewish General Hospital, Montreal, Quebec, Canada
Jean-Michel Senard
School of Medicine, University of Toulouse III, Faculté de Médecine, 31000 Toulouse, France
Robert Sheldon
Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
Win-Kuang Shen
Mayo Medical School, Mayo Clinic, Rochester, MN, USA
Jasbir Sra
University of Wisconsin- Milwaukee, Milwaukee, WI, USA
John Stephenson
Fraser of Allander Neurosciences Unit, Royal Hospital for Sick Children, Glasgow G3 8SJ, Scotland
Division of Developmental Medicine, University of Glasgow, Scotland
Julian M. Stewart
Center for Hypotension, New York Medical College, Hawthorne, NY 10532, USA
Richard Sutton
Royal Brompton Hospital, London, UK
Hidetaka Tanaka
Department of Developmental Pediatrics, Osaka Medical College Hospital, Osaka 569-8686, Japan
George Theodorakis
2° Department of Cardiology, Onassis Cardiac Surgery Center, Athens, Greece
Andrea Ungar
Department of Critical Care Medicine and Surgery—Unit of Geriatrics and Gerontology, University of Florence, 50141 Florence, Italy
A.A.M. Wilde
Department of Cardiology, Academic Medical Center Amsterdam, 1105 AZ Amsterdam, The Netherlands
Footnotes
The list of co-authors belonging to the AD Hoc Syncope Consortium is given in the appendix. 
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