The association between the diameter of a patent foramen ovale and the risk of embolic cerebrovascular events

PURPOSE: We sought to determine whether the size of a patent foramen ovale affected the risk of embolic cerebrovascular events of unknown origin. PATIENTS AND METHODS: We ascertain the presence and measured the size of pa tent foramen ovale using multiplane transesophageal echocardiography in 121 consecutive patients younger than 60 years who had transient ischemic atta cks or ischemic strokes and in 123 control subjects. None of the patients h ad left heart, aortic, or carotid sources of embolism, or echocardiographic signs of elevated left or right atrial pressure. We used multivariate logi stic regression to determine whether the size of the patent foramen ovale w as an independent risk factor for cerebrovascular events. RESULTS: The mean (+/- SD) diameter of a patent foramen ovale was significa ntly larger in patients (4 +/- 2 mm) than in control subjects (2 +/- 1 mm, P <0.0001). A patent foramen ovale greater than 4 mm was associated with an increased risk of transient ischemic attacks [odds ratio (OR) = 3.4; 95% c onfidence interval (CI), 1.0 to 11, P = 0.04],ischemic strokes (OR = 12; 95 % CI, 3.3 to 44, P = 0.0001), and, especially, having evidence of two or mo re strokes (OR = 27; 95% CI, 4.7 to 160, P = 0.0002). CONCLUSION: The diameter of a patent foremen ovale is an independent risk f actor for ischemic events, especially recurrent strokes. Am J Med. 2000;109 :456-462. (C) 2000 by Excerpta Medica, Inc.