Presented in Journal club by Dr Fakhir Raza HaidriSpecialist MICU

1st November 2016

Introduction• Syncope: Defined as a transient loss of consciousness that has a rapid onset, short duration (in current study less than 1 minute), and spontaneous resolution and is believed to be caused by temporary cerebral hypoperfusion

Eur Heart J. 2009 Nov;30(21):2631-71. doi: 10.1093/eurheartj/ehp298. Epub 2009 Aug 27

Flow chart of Syncopal Attack

Eur Heart J. 2009 Nov; 30(21): 2631–2671.

Pathophysiology

Eur Heart J. 2009 Nov; 30(21): 2631–2671.

Background• The prevalence of pulmonary embolism among patients hospitalized

for syncope is not well documented, and current guidelines pay little attention to a diagnostic workup for pulmonary embolism in these patients.

Question• Do All Patients with 1st Time Syncope need a Pulmonary Embolism

Workup?• Outcome measure: Prevalence of Pulmonary Embolism among

Patients with a First Episode of Syncope

Methods• Cross sectional study• older than 18 years of age• first episode of syncope• Definition of syncope used: Syncope was defined as a transient loss of

consciousness with rapid onset, short duration (i.e., <1 minute), and spontaneous resolution, with obvious causes such as epileptic seizure, stroke, and head trauma ruled out

Exclusion criteria• Previous Episodes of Syncope• On Anticoagulation Therapy• Pregnant• Did Not Provide Informed Consent

Method• 2584 patients with first-time syncope were screened in 11 Italian

emergency departments – 9 of which were non-academic• 72% of these patients were discharged home based on a clinical

evaluation by a physician in the emergency department• 717 patients were admitted to the hospital• 157 were excluded for the following reasons: 118 were receiving

anticoagulation therapy, 82 had atrial fibrillation, 36 had other reasons, 35 had recurrent syncope, 4 declined to participate.• So 560 inpatients were then all evaluated for pulmonary embolus.

Following criteria applied in 560 patients

Summary of Patients in the study

Thrombotic Burden• CT finding Among the 72 patients in whom PE confirmed• Main pulmonary artery in 30 patients (41.7%),• Lobar artery in 18 patients (25.0%),• Segmental artery in 19 patients (26.4%),• Subsegmental artery in 5 patients (6.9%).

Thrombotic Burden• VQ finding in 24 patients• Perfusion defect involved more than 50% of the area of both lungs in

4 patients• 26 to 50% of the area of both lungs in 8 patients• 1 to 25% of the area of both lungs in the remaining 12 patients• In the 1 patient who died, pulmonary embolism involved both main

pulmonary arteries.

Clinical symptoms in confirmed PE patients• Tachypnea: 45.4% vs. 7.1%• Tachycardia: 33.0% vs. 16.2%• Hypotension: 36.1% vs. 22.9%• clinical signs or symptoms of deep-vein thrombosis: 40.2% vs. 4.5%

previous venous thromboembolism: 11.3% vs. 4.3%• Active cancer 19.6% vs. 9.9%• No clinical manifestations 24.7%

Conclusion• Among patients who were hospitalized for a first episode of syncope

and who were not receiving anticoagulation therapy, pulmonary embolism was confirmed in 17.3% (approximately one of every six patients). • The rate of pulmonary embolism was highest among those who did

not have an alternative explanation for syncope

DiscussionPatient Population or Problem: Intervention (or Exposure): Which medical event or therapy do you

need to study the effect of? NON INTERVENTIONALComparison (if known): With what will you compare the

intervention's results? NO COMPARISONOutcomes: What are the relevant effects (outcomes) you'll be

monitoring? IT WAS CROSS SECTIONAL STUDY, PATIENTS NOT FOLLOWED, MORTALITY NOT ASSESSED

Strengths• Multi center study• Presence or absence of PE assessed with a validated algorithm based

on pretest clinical probability

Limitations (weaknesses)• Hugely biased selection of patients (None of the discharged patients

included)• A specific syncope workup was not mandated by all hospitals involved

in the study• Imaging for PE was only performed in patients with an elevated D-

Dimer and/or had a high pretest probability for PE• Confirmation of DVT in symptomatic patients was also not mandated

Limitations (weaknesses)• Search for other causes of syncope was left to the discretion of the

physician, meaning other causes of syncope may have been under reported• No information was collected on treatment and follow-up of patients;

therefore, we don’t know what the clinical outcomes of these patients was• Imaging to confirm PE was not done at admission, but up to 48 hours

after admission. Immobility during hospitalization is a known to cause VTE

Other points in discussion• Authors conclusion of PE confirmation in approximately one in every

six patients (17.3%) however these numbers are grossly inflated. 2427 patients were actually included in this study (157 were excluded). Excluding all patients will overestimate the results, as was done in this study• 97 patients had PE confirmed so instead of 97/230 (42.2%) the

number should be 97/2427 (3.9%)• To take this one step further…if you exclude subsegmental PEs (i.e.

Unclear clinical significance) the number is actually 80/2427 (3.2%)