Right-to-left shunt and the hypercoagulable state: does paradoxical embolism play a role in patients with antiphospholipid syndrome and stroke?

Abstract

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 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.

Keywords

• síndrome antifosfolipídica
• acidente vascular cerebral isquêmico
• embolia paradoxal
• shunt direita-esquerda