Venous thrombo-embolic events as the probable cause of arterial ischemic event in patients with patent foramen ovale

Abstract Introduction The origin of the emboli involved in patent foramen ovale (PFO)-related embolic events remains mostly unknown. Purpose To evaluate the venous thrombo-embolic (VTE) origin of patients with PFO-related embolic event. Methods Patients planned for PFO closure for secondary prevention of PFO-related arterial embolic event had a systematic venous thrombo-embolic (VTE) risk evaluation that included : an extensive questionnaire on past history of VTE events, clinical situations at high risk of VTE including complicated hemorrhoids, prior saphenectomy or venous sclerosis, varicocele, intrapelvic tumor, pregnancy, surgery or prolonged travel or presence of hyperthrombotic state (i.e., thrombophilia, active cancer or covid) and an abdominopelvic magnetic resonance venography (MRV) evaluation to identify any intrapelvic venous disease. Results From July 2020 to May 2023, 366 consecutive patients (Median age 51 [42-58] years, 42.9% female) were prospectively included. A past medical VTE events, a high risk VTE situation, a hyperthrombotic state and a pelvic venous abnormality on MRV 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), respectively, and 58.5% (95%CI 53.4-63.4) of the patients presented at least one of the previous conditions. MRV identified various undiagnosed pelvic venous abnormalities with 20.0% of pelvic varices, 9.8% of May-Thurner-Cockett and 7.4% of Nutcracker phenomenons (Figure 1). 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). Conclusion A majority of patients undergoing PFO closure for secondary prevention have a potential VTE source of paradoxical emboli suggesting that VTE events is the probable cause of arterial ischemic event in these patients.