ASSOCIATION BETWEEN ATRIAL SIZE AND CEREBROVASCULAR EVENTS: A RETROSPECTIVE, COHORT STUDY

Background: Left atrial enlargement (LAE) is a cardiac structural abnormality linked to cardiovascular risk, including stroke. However, its independent prognostic role in patients without atrial fibrillation (AF) remains unclear. We carried out a prospective cohort study to assess the association between LAE, detected using the left atrial volume index (LAVi), and cerebrovascular events (CVE). Methods: We enrolled consecutive adults undergoing transthoracic echocardiography (TTE) between 2012 and 2023 at three teaching hospitals in Milan, Italy. Patients with a history of AF or receiving anticoagulant therapy were excluded. Only the first TTE of each calendar year was included in the analysis (index echocardiogram). LAE was categorized by LAVi as absent (≤34 mL/m²), mild (>34 and ≤41 mL/m²), moderate (>41 and ≤48 mL/m²), or severe (>48 mL/m²). The primary outcome was a composite of ischemic stroke or transient ischemic attack (TIA) within 1 year of the index echocardiogram. The secondary outcomes were the individual components of the primary endpoint (ischemic stroke and TIA) within 1 year. Multivariate logistic regression models were used to evaluate the independent association of LAE with 1-year cerebrovascular events (CVEs), adjusting for variables such as age, diabetes, and prior stroke. Results: We included 53,109 subjects with a median age of 66 years (48% female). CVEs occurred in 1,318 subjects (2.5%). The 1-year event rate was significantly higher in patients with some degree of LAE (3.9%) compared to those with a normal LAVi (2.0%; p<0.0001). In the multivariate analysis, all categories of LAE were associated with 1-year CVEs compared with no LAE (mild: OR 1.21, 95% CI 1.03–1.43; moderate: OR 1.48, 95% CI 1.20–1.83; severe: OR 1.85, 95% CI 1.54–2.22). This association was independent of other significant predictors, including diabetes, prior stroke, heart failure or left ventricular dysfunction, male sex, age >65 years, and antiplatelet therapy. Conclusions: LAE defined by LAVi is an independent predictor of 1-year cerebrovascular events in subjects without known AF and without ongoing anticoagulation. These findings suggest that LAVi can serve as a valuable marker to refine risk stratification for cerebrovascular events.