Right-to-left shunt and the hypercoagulable state: does paradoxical embolism play a role in patients with antiphospholipid syndrome and stroke?
OBJECTIVE
Patent foramen ovale is associated with paradoxical embolism (PE) and stroke. Hypercoagulable states, such as antiphospholipid syndrome (APS), can exacerbate PE by increasing clot formation. The aim of this study was to verify whether patients with APS and stroke present a right-to-left shunt (RLS) with greater frequency than patients with APS but without stroke.


METHODS
Fifty-three patients with APS were tested for RLS using contrast-enhanced transcranial Doppler (cTCD): 23 patients had a history of stroke (Stroke Group) and 30 had no history of stroke (No-stroke Group).


RESULTS
cTCD was positive in 15 patients (65%) from the Stroke Group and in 16 patients (53%) in the No-stroke Group (p=0.56). The proportion of patients with a small RLS (<10 high-intensity transient sign or HITS) and a large RLS (>10 HITS) was similar between the groups without significant difference.


CONCLUSIONS
Our data do not support the theory that paradoxical embolism may play an important role in stroke in APS patients.
Neurology Division, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil. lnzamproni@yahoo.com.br
Laura Nicoleti
LN
Zamproni
Viviane Flumignan
VF
Zétola
Marcos Christiano
MC
Lange
D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000032:analysis; D016736:Antiphospholipid Syndrome / Q000150:complications* / Q000000981:diagnostic imaging; D001778:Blood Coagulation Disorders / Q000150:complications; D003287:Contrast Media; D003430:Cross-Sectional Studies; D019320:Embolism, Paradoxical / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012965:Sodium Chloride; D020521:Stroke / Q000000981:diagnostic imaging / Q000209:etiology*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods
D017152:Antibodies, Antiphospholipid; D003287:Contrast Media; D012965:Sodium Chloride