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

Background: Patent foramen ovale and atrial septal aneurysm have been ident ified as potential risk factors for stroke, but information about their eff ect on the risk of recurrent stroke is limited. We studied the risks of rec urrent cerebrovascular events associated with these cardiac abnormalities. Methods: A total of 581 patients (age, 18 to 55 years) who had had an ische mic stroke of unknown origin within the preceding three months were consecu tively 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 p atent 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 at rial septal aneurysm, and 4.2 percent (95 percent confidence interval, 1.8 to 6.6 percent) among the patients with neither of these cardiac abnormalit ies. There were no recurrences among the patients with an atrial septal ane urysm alone. The presence of both cardiac abnormalities was a significant p redictor of an increased risk of recurrent stroke (hazard ratio for the com parison with the absence of these abnormalities, 4.17; 95 percent confidenc e 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 aneu rysm who have had a stroke constitute a subgroup at substantial risk for re current stroke, and preventive strategies other than aspirin should be cons idered. (N Engl J Med 2001;345:1740-6.) Copyright (C) 2001 Massachusetts Me dical Society.