Original Article

Prevalence and Predictors of Pulmonary Embolism in Hospitalized Patients with Syncope

Authors: Hussam Ammar, MD, Chaand Ohri, MD, Said Hajouli, MD, Shaunak Kulkarni, MD, Eshetu Tefera, MS, Ragai Fouda, PhD, MD, Rukma Govindu, MD


Objectives: Approximately one in six patients hospitalized with syncope have pulmonary embolism (PE), according to the PE in Syncope Italian Trial study. Subsequent studies using administrative data have reported a PE prevalence of <3%. The aim of the study was to determine the prevalence and predictors of PE in hospitalized patients with syncope.

Methods: We retrospectively reviewed the records of patients who were hospitalized in the MedStar Washington Hospital Center between May 1, 2015 and June 30, 2017 with deep venous thrombosis, PE, and syncope. Only patients who presented to the emergency department with syncope were included in the final analysis. PE was diagnosed by either positive computed tomographic angiography or a high-probability ventilation-perfusion scan. Univariate and multivariate logistic regressions were used to assess the associations between clinical variables and the diagnosis of PE in patients with syncope.

Results: Of the 408 patients hospitalized with syncope (mean age, 67.5 years; 51% men [N = 208]), 25 (6%) had a diagnosis of PE. Elevated troponin levels (odds ratio 6.6, 95% confidence interval 1.9–22.9) and a dilated right ventricle on echocardiogram (odds ratio 6.9, 95% confidence interval 2.0–23.6) were independently associated with the diagnosis of PE. Age, active cancer, and history of deep venous thrombosis were not associated with the diagnosis of PE.

Conclusions: The prevalence of PE in this study is approximately one-third of the reported prevalence in the PE in Syncope Italian Trial study and almost three times the value reported in administrative data-based studies. PE should be suspected in patients with syncope and elevated troponin levels or a dilated right ventricle on echocardiogram.
Posted in: Miscellaneous Pulmonary Disorders (Indications for Spirometry)2

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1. Mendu ML, McAvay G, Lampert R, et al. Yield of diagnostic tests in evaluating syncopal episodes in older patients. Arch Intern Med 2009;169:1299-1305.
2. Shen WK, Decker WW, Smars PA, et al. Syncope Evaluation in the Emergency Department Study (SEEDS): a multidisciplinary approach to syncope management. Circulation 2004;110:3636-3645.
3. Brignole M, Menozzi C, Bartoletti A, et al. A new management of syncope: prospective systematic guideline-based evaluation of patients referred urgently to general hospitals. Eur Heart J 2006;27:76-82.
4. Kapoor WN, Karpf M, Wieand S, et al. A prospective evaluation and follow-up of patients with syncope. N Engl J Med 1983;309:197-204.
5. Johnson PC, Ammar H, Zohdy W, et al. Yield of diagnostic tests and its impact on cost in adult patients with syncope presenting to a community hospital. South Med J 2014;107:707-714.
6. Farwell DJ, Sulke AN. Does the use of a syncope diagnostic protocol improve the investigation and management of syncope? Heart 2004;90:52-58.
7. Frizell A, Fogel N, Steenblik J, et al. Prevalence of pulmonary embolism in patients presenting to the emergency department with syncope. Am J Emerg Med 2018;36:253-256.
8. Thiruganasambandamoorthy V, Kwong K, Wells GA, et al. Development of the Canadian Syncope Risk Score to predict serious adverse events after emergency department assessment of syncope. CMAJ 2016;188:E289-E298.
9. Quinn JV, Stiell IG, McDermott DA, et al. Derivation of the San Francisco Syncope Rule to predict patients with short-term serious outcomes. Ann Emerg Med 2004;43:224-232.
10. Prandoni P, Lensing AWA, Prins MH, et al. Prevalence of pulmonary embolism among patients hospitalized for syncope. N Engl J Med 2016;375:1524-1531.
11. Costantino G, Ruwald MH, Quinn J, et al. Prevalence of pulmonary embolism in patients with syncope. JAMA Intern Med 2018;178:356-362.
12. Verma AA, Masoom H, Rawal S, et al. Pulmonary embolism and deep venous thrombosis in patients hospitalized with syncope: a multicenter cross-sectional study in Toronto, Ontario, Canada. JAMA Intern Med 2017;177:1046-1048.
13. Roncon L, Zuin M, Casazza F, et al. Impact of syncope and pre-syncope on short-term mortality in patients with acute pulmonary embolism. Eur J Intern Med 2018;54:27-33.
14. Shen WK, Sheldon RS, Benditt DG, et al. 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation 2017;136:e60-e122.
15. Brignole M, Moya A, de Lange FJ, et al. 2018 ESC guidelines for the diagnosis and management of syncope. Eur Heart J 2018;39:1883-1948.
16. Mason J, Herbert M, Schriger DL. Pulmonary embolism prevalence in admitted syncope patients: 1 in 6 really?: answers to the March 2017 journal club questions. Ann Emerg Med 2017;70:257-260.
17. Batty J, Tang M. Pulmonary embolism in patients hospitalized for syncope. N Engl J Med 2017;376:494-497.
18. Ruwald MH, Hansen ML, Lamberts M, et al. Accuracy of the ICD-10 discharge diagnosis for syncope. Europace 2013;15:595-600.
19. Furlan L, Solbiati M, Pacetti V, et al. Diagnostic accuracy of ICD-9 code 780.2 for the identification of patients with syncope in the emergency department. Clin Auton Res 2018;28:577-582.
20. Burles K, Innes G, Senior K, et al. Limitations of pulmonary embolism ICD-10 codes in emergency department administrative data: let the buyer beware. BMC Med Res Methodol 2017;17:89.
21. Keller K, Beule J, Balzer JO, et al. Syncope and collapse in acute pulmonary embolism. Am J Emerg Med 2016;34:1251-1257.
22. Wolfe TR, Allen TL. Syncope as an emergency department presentation of pulmonary embolism. J Emerg Med 1998;16:27-31.
23. Dalen JE, Mathur VS, Evans H, et al. Pulmonary angiography in experimental pulmonary embolism. Am Heart J 1966;72:509-520.
24. Thames MD, Alpert JS, Dalen JE. Syncope in patients with pulmonary embolism. JAMA 1977;238:2509-2511.
25. Theilade J, Winkel BG, Holst AG, et al. A nationwide, retrospective analysis of symptoms, comorbidities, medical care and autopsy findings in cases of fatal pulmonary embolism in younger patients. J Thromb Haemost 2010;8:1723-1729.
26. Sardi A, Gluskin J, Guttentag A, et al. Saddle pulmonary embolism: is it as bad as it looks? A community hospital experience. Crit Care Med 2011;39:2413-2418.
27. Altinsoy B, Erboy F, Tanriverdi H, et al. Syncope as a presentation of acute pulmonary embolism. Ther Clin Risk Manag 2016;12:1023-1028.
28. Akinboboye OC, Brown EJ, Jr Queirroz R, et al. Recurrent pulmonary embolism with second-degree atrioventricular block and near syncope. Am Heart J 1993;126(3 Part 1):731-732.
29. Chen SY, Wang YH, Hwang JJ, et al. Pulmonary embolism presenting as syncope in paraplegia: a case report. Arch Phys Med Rehabil 1995;76:387-390.
30. Simpson RJ, Jr Podolak R, Mangano CA, Jr et al. Vagal syncope during recurrent pulmonary embolism. JAMA 1983;249:390-393.
31. Sun BC, Derose SF, Liang LJ, et al. Predictors of 30-day serious events in older patients with syncope. Ann Emerg Med 2009;54:769-778.e1-e5.