Prevalence of atrial septal pouch and risk of ischemic stroke.

BACKGROUND: It has been postulated that atrial septal pouch (ASP) may favor the stasis of blood and predispose to thromboembolic complications. We sought to evaluate the prevalence of ASP, and its association with ischemic stroke.

METHODS: We retrospectively studied 500 patients, who underwent transesophageal echocardiography (TEE) due to clinical indications. Seventy two patients due to image quality, and 104 patients with atrial septal defect or PFO were excluded. The remaining 324 patients were included in the analysis. The depth of ASP was measured.

RESULTS: ASP was detected in 98 patients [left side ASP (LASP) in 58 (59.2%), and right side ASP (RASP) in 40 (40.8%) patients]. LASPs were significant deeper than RASPs (10.1±5.2 vs 4.4±1.4mm, p<0.0001). Patient characteristics were categorized by the presence or absence of LASP. The age (61±12 vs 61±12), gender and stroke risk factors were no significant difference between patients with or without LAPS. Ischemic stroke occurred in 21 patients without LASP, 10 patients with LASP. The presence of a LASP was found to be associated with an increased risk of ischemic stroke, in either univariable analysis (17.2 vs. 7.9%, p=0.03; OR=2.43, 95% CI=1.1-5.5, p=0.033) or after adjustment for other stroke risk factors using multiple logistic regression analysis (OR=2.45, 95% CI 1.1-5.8, p=0.036).

CONCLUSIONS: This study demonstrated evidence of association between LASP and ischemic stroke. Among 324 patients, the risk of ischemic stroke was twice more among patients with LASP than cases without LASP.