Individualized Treatment of Foramen Ovale and Stroke

Abstract

I read with interest Dalen’s editorial1Dalen J.E. Are patients with a patent foramen ovale at increased risk of stroke? A billion dollar question.Am J Med. 2007; 120: 472-474Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar on whether patients who harbor a patent foramen ovale (PFO) are at increased risk of strokes or not, and contend the following: In regard to the increased risk of recurrent stroke and venous thromboembolism, 41% of patients with stroke or transient ischemic attack (TIA) were found to have a PFO in the Lausanne study.2Bogousslavsky J. Garazi S. Jeanrenaud X. et al.Stroke recurrence in patients with patent foramen ovale: the Lausanne Study: Lausanne Stroke with Paradoxical Embolism Study Group.Neurology. 1996; 46: 1301-1305Crossref PubMed Google Scholar Venous thrombosis was detected in 5.5%, and other studies show annual stroke recurrence rates of up to 12% in patients with cryptogenic stroke.2Bogousslavsky J. Garazi S. Jeanrenaud X. et al.Stroke recurrence in patients with patent foramen ovale: the Lausanne Study: Lausanne Stroke with Paradoxical Embolism Study Group.Neurology. 1996; 46: 1301-1305Crossref PubMed Google Scholar, 3Mas J.L. Zuber M. Recurrent cerebrovascular events in patients with patent foramen ovale, atrial septal aneurysm, or both and cryptogenic stroke or transient ischemic attack: French Study Group on Patent Foramen Ovale and Atrial Septal Aneurysm.Am Heart J. 1995; 130: 1083-1088Abstract Full Text PDF PubMed Scopus (374) Google Scholar, 4Cujec B. Mainra R. Johnson D.H. Prevention of recurrent cerebral ischemic events in patients with patent foramen ovale and cryptogenic strokes or transient ischemic attacks.Can J Cardiol. 1999; 15: 57-64PubMed Google Scholar The French Study Group3Mas J.L. Zuber M. Recurrent cerebrovascular events in patients with patent foramen ovale, atrial septal aneurysm, or both and cryptogenic stroke or transient ischemic attack: French Study Group on Patent Foramen Ovale and Atrial Septal Aneurysm.Am Heart J. 1995; 130: 1083-1088Abstract Full Text PDF PubMed Scopus (374) Google Scholar found that the risk of stroke or TIA was not increased in patients with cryptogenic stroke and a PFO alone treated with aspirin, but the risk was increased from 4.7% to 8.0% in patients with a PFO and an atrial septal aneurysm (ASA). Therefore, many of us think that the combination of an ASA and a PFO is a significant risk factor for cerebral embolic ischemia in patients with recurrent cryptogenic stroke. There are conflicting reports on transvenous closure of PFOs and the risk of recurrent stroke. Ruchat et al.5Ruchat P. Bogousslavsky J. Hurni M. et al.Systematic surgical closure of patent foramen ovale in selected patients with cerebrovascular events due to paradoxical embolism: early results of a preliminary study.Eur J Cardiothorac Surg. 1997; 11: 824-827Crossref PubMed Scopus (83) Google Scholar demonstrated that patients with PFOs and cryptogenic strokes, or TIA who underwent closure had no recurrent vascular events. Similar results have been reported elsewhere.6Devuyst G. Bogousslavsky J. Ruchat P. et al.Prognosis after stroke followed by surgical closure of patent foramen ovale: a prospective follow-up study with brain MRI and simultaneous transesophageal and transcranial Doppler ultrasound.Neurology. 1996; 47: 1162-1166Crossref PubMed Scopus (170) Google Scholar There are situations in which a right-to-left shunt with a large PFO and ASA are found in the workup of a patient with cryptogenic TIA or ischemic stroke in whom one considers anticoagulation or PFO closure. What about a young diver with no other risk factors? What about the orthopedic surgery patient who has a TIA from fat emboli in need of more surgery? What about the patient with a hypercoagulable state? Although we would all like the results of properly designed randomized clinical trials before recommendations regarding PFO closure can be made, individual patient presentations and characteristics must guide clinical decision making. The Reply:The American Journal of MedicineVol. 120Issue 12PreviewI agree with Rison that there are many inconsistencies in the reports of stroke and patent foramen ovale (PFO). He notes that in the Lausanne study,1 venous thrombosis was detected in 5.5% of patients with stroke or transient ischemic attack (TIA). If the stroke/TIAs were due to paradoxical embolism, the incidence of venous thrombosis would have been much higher. The French study group2 reported that the risk of recurrent stroke/TIA was not increased in patients with cryptogenic stroke and a PFO who were treated with aspirin. Full-Text PDF