Diagnostic Yield of Venous Thrombosis and Pulmonary Embolism by Combined CT Venography and Pulmonary Angiography in Patients with Cryptogenic Stroke and Patent Foramen Ovale.

Background: Paradoxical embolism via a patent foramen ovale (PFO) has been suggested as a potential stroke mechanism. Combined CT venography and pulmonary angiography (CVPA) is a simple, validated and accurate technique to diagnose deep venous thrombosis (DVT) or pulmonary embolism (PE). We sought to assess the prevalence of DVT or PE among patients with PFO and cryptogenic stroke (CS) by CVPA.

Methods: Patients were identified retrospectively from a clinical registry of consecutive patients with stroke admitted to our Stroke Unit. The following criteria were required for inclusion in this study: CS, PFO identified by transthoracic echography using contrast medium and CVPA performed during the hospitalization following stroke.

Results: A total of 114 patients with PFO underwent a CVPA within 7 days (interquartile range 4-9) from stroke symptom onset. On cerebral imaging, 11% had multiple infarcts. CVPA documented deep vein thrombosis (DVT) in 10 patients (8.8%) and PE in 5 patients (4.4%), that is, a total of 12 patients with prevalence of 10.5% (95% CI 5.5-17.7). Patients with PE-DVT had higher D-dimers and C reactive protein level than patients without PE-DVT (p < 0.05).

Conclusion: CVPA may be used by the stroke team in the work-up of suspected paradoxical embolism among cryptogenic ischemic stroke patients with PFO.