Purpose: Impending paradoxical embolism (IPDE) occurs when thrombus is entrapped within a patent foramen ovale (PFO), most frequently occurring in the setting of acute pulmonary embolism. We aimed to review all reported cases of IPDE, compare survival with each treatment method and identify patient characteristics within each group.
Methods: Systematic electronic literature searches using a pre-defined search strategy identified 239 patients for inclusion in the review. Disease, demographic, treatment and mortality data was collected for analysis. Authors of manuscripts were contacted if information was incomplete. Non-english language studies were translated for inclusion.
Results: 239 case reports were included for review. There were 110 males and 129 females and the average age was 58 years. Common presenting symptoms were dyspnoea (74%), chest pain (28%), stroke/TIA (26%) and syncope/presyncope (23%). Most patients (82%) had pulmonary embolism confirmed by imaging. 73 patients (30%) experienced systemic embolism prior to diagnosis of IPDE. IPDE was diagnosed most frequently using transthoracic and transoesophageal echocardiography. Reported treatments included emergency surgery, thrombolysis and anticoagulation. Mortality at discharge was 15% in the surgery group, 18% in the anticoagulation group and 28% in the thrombolysis group (p=0.016). There was some evidence that male sex and patients presenting with cardiac arrest, hypotension and haemoptysis were more likely to be deceased at hospital discharge. In adjusted multivariate analysis, treatment modality was not significantly associated with mortality at discharge.
Conclusions: This is the largest review of IPDE to date and attempts to provide clinicians with information regarding the diagnosis and management of this infrequently reported condition. The absence of prospective studies limits the conclusions that can be drawn from this review. Reported mortality at discharge was lower in the surgery and anticoagulation groups, however this difference was not significant in multivariate modelling.