Background: Studies to date have shown an association between the presence of patent foramen ovale and cryptogenic stroke in patients younger than 55 years of age. This association has not been established in patients 55 years of age or older.
Methods: We prospectively examined 503 consecutive patients who had had a stroke, and we compared the 227 patients with cryptogenic stroke and the 276 control patients with stroke of known cause. We examined the prevalences of patent foramen ovale and of patent foramen ovale with concomitant atrial septal aneurysm in all patients, using transesophageal echocardiography. We also compared data for the 131 younger patients (< 55 years of age) and those for the 372 older patients (> or = 55 years of age).
Results: The prevalence of patent foramen ovale was significantly greater among patients with cryptogenic stroke than among those with stroke of known cause, for both younger patients (43.9% vs. 14.3%; odds ratio, 4.70; 95% confidence interval [CI], 1.89 to 11.68; P<0.001) and older patients (28.3% vs. 11.9%; odds ratio, 2.92; 95% CI, 1.70 to 5.01; P<0.001). Even stronger was the association between the presence of patent foramen ovale with concomitant atrial septal aneurysm and cryptogenic stroke, as compared with stroke of known cause, among both younger patients (13.4% vs. 2.0%; odds ratio, 7.36; 95% CI, 1.01 to 326.60; P=0.049) and older patients (15.2% vs. 4.4%; odds ratio, 3.88; 95% CI, 1.78 to 8.46; P<0.001). Multivariate analysis adjusted for age, plaque thickness, and presence or absence of coronary artery disease and hypertension showed that the presence of patent foramen ovale was independently associated with cryptogenic stroke in both the younger group (odds ratio, 3.70; 95% CI, 1.42 to 9.65; P=0.008) and the older group (odds ratio, 3.00; 95% CI, 1.73 to 5.23; P<0.001).
Conclusions: There is an association between the presence of patent foramen ovale and cryptogenic stroke in both older patients and younger patients. These data suggest that paradoxical embolism is a cause of stroke in both age groups.
2007 Massachusetts Medical Society