Patients with symptomatic pulmonary embolism (PE) and patent foramen ovale (PFO) had a higher rate of recent ischemic stroke than patients without PFO, according to study results recently published in the Annals of Internal Medicine. This lends evidence to the role of paradoxical embolism in increasing the risk for ischemic stroke in patients with PFO.

This prospective cohort study included 361 participants (median age, 66 years) with symptomatic acute PE who were consecutively admitted to 4 French hospitals between November 2009 and December 2015. Participants were examined using cerebral magnetic resonance imaging (MRI) and systematic contrast transthoracic echocardiography (TTE) within 1 week of enrolling in the study. The primary objective of this study was to identify the rate of recent ischemic stroke in persons with symptomatic PE and PFO vs persons without PFO. Diagnosis of silent or recent symptomatic ischemic stroke was based on imaging and clinical results. Symptomatic ischemic stroke was diagnosed if transient or permanent clinical signs were identified and if an MRI indicated recent stroke whereas asymptomatic ischemic stroke was diagnosed if there was a lack of symptoms or signs but an MRI scan indicated a recent stroke.

PFO was identified in 13% (n=43) of participants using contrast TTE, which was conclusive among 324 of 361 participants. Deep venous thrombosis was identified among 51% (145 of 284), cardiovascular risk factors among 91% (279 of 306), and arrhythmia among 10% (16 of 151). No significant intergroup differences were found in general characteristics, history of stroke, venous thromboembolism, or cardiovascular disease, arrhythmia, presentation of PE, or current anticoagulant or antiplatelet therapy. A conclusive cerebral MRI result was obtained in 315 participants. Individuals with PFO had more frequent recent ischemic stroke than individuals without (21.4% vs 5.5%), yielding a relative risk of 3.9 (95% CI, 1.62-8.67).

Limitations to this study included a lower-than-expected frequency of PFO among the participants, a small incidence of recent ischemic stroke, and the exclusion of certain participants because of technical issues.

The study researchers concluded that “patients with acute PE are at high risk for stroke. Patients with both PE and PFO have higher risk for recent ischemic stroke than patients with PE and no PFO. This finding supports the hypothesis that paradoxical embolism is an important mechanism of ischemic stroke in patients with concomitant PFO and PE. Nevertheless, whether patients with PE should be screened for PFO in daily practice remains to be determined.”

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Disclosures: Several authors reported financial associations with pharmaceutical companies. For a full list of disclosures, see the reference.

Reference

Le Moigne E, Timsit S, Ben Salem D, et al. Patent foramen ovale and ischemic stroke in patients with pulmonary embolism [published online May 7, 2019]. Ann Intern Med. doi: 10.7326/M18-3485