Left Atrial Enlargement and the Risk of Stroke: A Meta-Analysis of Prospective Cohort Studies

Background: The association between left atrial size and the risk of stroke has not been fully understood. We performed a meta-analysis of prospective cohort studies to determine whether left atrial enlargement (LAE) is associated with an increased risk of stroke. Methods: We searched PubMed, EMBASE, Web of Science, and the Cochrane Library through May 2019. Prospective cohort studies were included if they reported hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of stroke with respect to LAE. All meta-analyses were performed using a random-effects model. Results: Six studies involving 66,007 participants and 3,549 stroke events were included. Compared with patients without LAE, those with LAE had an increased risk of stroke (adjusted HR 1.68, 95% CI 1.36-2.07). There was also a graded association with stroke relating to LAE (adjusted HR for mild LAE 1.50, 95% CI 0.98-2.28; moderate LAE 1.40, 95% CI 1.12-1.75; and severe LAE 1.59, 95% CI 1.33-1.90). Furthermore, for each increase of 1 cm in left atrial diameter, the odds of stroke were increased by 24% (adjusted HR 1.24, 95% CI 1.03-1.50). Conclusions: Our meta-analysis demonstrated that LAE is associated with an increased and graded risk of stroke.