Effect of atrial septal aneurysm on risk of cerebrovascular events in Japanese patients

Background: The aim of the present study was to determine whether atrial septal aneurysm (ASA) detected by transthoracic echocardiography (TTE) is an independent risk factor of cerebrovascular events for Japanese people. Methods: A control study was conducted with 178 patients with ASA (follow-up rate, 96.7%; median follow-up period, 5.6 years) and 176 control patients (follow-up rate, 97.8%; median follow-up period, 5.4 years), selected from 42 528 consecutive patients who underwent TTE in the Omiya Medical Center, Jichi Medical School, from April 1991 to March 2001. Data were collected by structured review of patient charts and a subsequent telephone survey. Long-term cerebrovascular risk factors were evaluated by logistic regression analysis. Results: A previous episode of cerebral infarction had occurred in nine ASA patients (5.1%) and 11 control patients (6.3%). During the follow-up period, new cerebral infarction occurred in 12 ASA patients (6.7%) and six control patients (3.4%). Only atrial fibrillation was found to be an independent risk factor of new cerebral infarction (OR, 5.06; 95% CI, 1.32–19.46; P=0.04). Conclusions: ASA is not an independent risk factor of cerebrovascular events for Japanese patients. Thus, aggressive strategies such as anticoagulation are not essential for ASA patients without embolic episodes.