Recurrent cerebrovascular events associated with patent foramen ovale, atrial septal aneurysm, or both.

Background: Patent foramen ovale and atrial septal aneurysm have been identified as potential risk factors for stroke, but information about their effect on the risk of recurrent stroke is limited. We studied the risks of recurrent cerebrovascular events associated with these cardiac abnormalities. Methods: A total of 581 patients (age, 18 to 55 years) who had had an ischemic stroke of unknown origin within the preceding three months were consecutively enrolled at 30 neurology departments. All patients received aspirin (300 mg per day) for secondary prevention. Results: After four years, the risk of recurrent stroke was 2.3 percent (95 percent confidence interval, 0.3 to 4.3 percent) among the patients with patent foramen ovale alone, 15.2 percent (95 percent confidence interval, 1.8 to 28.6 percent) among the patients with both patent foramen ovale and atrial septal aneurysm, and 4.2 percent (95 percent confidence interval, 1.8 to 6.6 percent) among the patients with neither of these cardiac abnormalities. There were no recurrences among the patients with an atrial septal aneurysm alone. The presence of both cardiac abnormalities was a significant predictor of an increased risk of recurrent stroke (hazard ratio for the comparison with the absence of these abnormalities, 4.17; 95 percent confidence interval, 1.47 to 11.84), whereas isolated patent foramen ovale, whether small or large, was not. Conclusions: Patients with both patent foramen ovale and atrial septal aneurysm who have had a stroke constitute a subgroup at substantial risk for recurrent stroke, and preventive strategies other than aspirin should be considered. (N Engl J Med 2001;345:1740-6.) Copyright (C) 2001 Massachusetts Medical Society.