Association between atrial septal aneurysm and patent foramen ovale in young patients with recent stroke and normal carotid arteries

Background. The atrial septal aneurysm (ASA) has been considered a potential source of cardiogenic embolism for many years. The ASA-MI study evaluated the prevalence and characteristcs of ASA in patients (pts) with stroke and normal carotid arteries compared to control pts without stroke. The purpose of the present study was to evaluate the frequency of ASA and the association with patent foramen ovale (PFO) in the subgroup of younger patients (aged less than 55 years) included in the ASA-MI study.Methods. The ASAMI Study included 606 pts, enrolled between November 1990 and December 1996: 245 pts with a previous cerebral embolic attack and normal carotid study and a control group of 316 pts. They all underwent transthoracic and transesophageal echocardiography. The subgroup of younger patients aged less than 55 years included 90 patients (61 men and 29 women of mean age 49 + 5 years) (Group AY). This group was evaluated and compared with a control population age- and sex-matched (61 men; of mean age 48 + 6 years) (Group BY).Results. The prevalence of ASA was 48.8% (95% confidence interval 40% to 61%) in group AY and 22.2% in the group BY (95% confidence interval 18% to 33%) (X2 5.968 p=0.01). Comparing the 2 group of patients morphological features were similar. ASA involved the entire septum in 52% of pts of group AY, and in 47.2% of group BY. The prevalence of PFO was 58.8% (95% confidence interval 43% to 62%) in group AY and 28.8% in group BY (95% confidence interval 17% to 35%) (X2 5.811 p=0.01). A strong association was found between ASA and PFO. Of the 90 younger pts with stroke, 39 of 44 (88.6%) with ASA had also a PFO, compared with 14 of 46 (30.4%) without ASA (X2 7.370 p=0.007).Conclusion. We found that ASA and PFO were independent predictive factors for stroke in younger patients with stroke and normal carotid arteries and that the association between ASA and PFO bore an increased odds risk