The origin of emboli involved in patent foramen ovale (PFO)-related ischemic events remains poorly documented. Our objective was to evaluate venous thromboembolic (VTE) disease as a potential source of PFO-related embolic events.

Patients scheduled for PFO closure for secondary prevention of PFO-related arterial embolic events underwent a systematic VTE risk evaluation. This included: a) a detailed questionnaire on past VTE history to identify clinical situations associated with a high risk of VTE at the time of the embolic event, and b) abdominopelvic magnetic resonance imaging (MRI) with venography to identify abdominal or pelvic venous disease.

From July 2020 to May 2023, 366 consecutive patients (median age 51 [range, 42-58] years; 42.9% female) were prospectively included. A prior VTE event, a high-risk VTE situation, a hyperthrombotic state, or an abdominal or pelvic venous anomaly on MRI were present in 8.5% (95%CI, 6.0-11.8), 22.7% (95%CI, 18.7-27.2), 7.1% (95%CI, 4.9-10.2), and 36.3% (95%CI, 31.6-41.4) of patients, respectively. Overall, 58.5% (95%CI, 53.4-63.4) of patients had at least 1 of these conditions. MRI identified several previously undiagnosed pelvic venous anomalies, including pelvic varices in 20.0%, May-Thurner/Cockett in 9.8%, and nutcracker syndrome in 7.4%. Imaging abnormalities were more frequent among younger patients (aOR, 1.02; 95%CI, 1.00-1.04) and women (aOR, 1.94; 95%CI, 1.25-3.02).

A prior VTE event, a high-risk VTE situation, a hyperthrombotic state, or an abdominal or pelvic venous anomaly may be present in most patients with a history of a PFO-related arterial event.