Supplementary Material for: Left-Sided Atrial Septal Pouch as a Risk Factor of Cryptogenic Stroke: A Systematic Review and Meta-Analysis

Background: Despite some evidence of left-sided septal pouch (LSSP) involvement in the pathogenesis of cardioembolic stroke, the question of LSSP clinical significance still remains unsolved. In this study, we aimed to determine the association between the LSSP presence and cryptogenic stroke using meta-analytical approach. Methods: We performed a systematic review of electronic databases for studies that compared the presence of LSSP in subjects with cryptogenic stroke and non-stroke control. Data were extracted and pooled into a meta-analysis. Results: Seven studies (400 cryptogenic stroke patients and 1,456 non-stroke controls) were included in the meta-analysis. A total of 138 LSSPs were identified among the cryptogenic stroke patients, with a pooled prevalence of 29.8% (95% CI 17.5–43.7%), and 268 LSSPs were identified in the non-stroke controls, with a pooled prevalence of 21.0% (95% CI 13.7–29.5%). After meta-analysis, the risk of cryptogenic stroke was higher in patients with an LSSP than in patients without LSSP (OR 1.52; 95% CI 1.15–2.00; p < 0.001). No significant heterogeneity was detected across the included studies (p > 0.05). Conclusion: Our meta-analysis demonstrated association between LSSP and cryptogenic stroke. In our univariate analysis, the risk of cryptogenic stroke is higher among patients with LSSP than in cases without the LSSP.