Left Atrial Diameter and the Risk of Thromboembolism in Patients with Left Ventricular Noncompaction.

Aims: Patients with left ventricular noncompaction (LVNC) are at risk of thromboembolism. The relationship between left atrial diameter (LAD), a robust predictor for thrombosis, and LVNC is unclear. The purpose of this study was to explore the effect of LAD on the thrombotic risk in LVNC. Methods: In this retrospective cohort study, 320 patients with imaging characteristics of LVNC were included for statistical analysis. The primary endpoint was a composite event of intracardiac thrombi and stroke or transient ischemic attack (TIA). The secondary endpoints were intracardiac thrombi and stroke/TIA. Results: The 320 included patients (211 [65.9%] men, median age: 45 years [interquartile range: 30−57]) were divided into LAD1 (<43 mm, n = 157) and LAD2 (≥43 mm, n = 163) groups based on the median LAD. Throughout the median follow-up of 34 months, the incidence of thromboembolism among them was 7.2%: 11 (3.4%) patients had stroke/TIA and 14 (4.4%) had intracardiac thrombi. The rate of thromboembolism in the LAD2 group was higher than that of patients in the LAD1 group (11.0% vs. 3.2%, p = 0.007). Kaplan−Meier survival curves suggested that a LAD ≥ 43 mm was associated with a higher risk of thromboembolism and intracardiac thrombi (log-rank test, all p < 0.05). After adjusting for potential risk factors, LAD ≥ 43 mm was found to be an independent risk factor for thromboembolism (p = 0.013) and stroke (p = 0.024). The area under the receiver operating characteristic curve of LAD for predicting thromboembolism reached 0.696 at 1 year, 0.635 at 2 years, and 0.660 at 3 years. Conclusions: A larger LAD was related to a higher risk of thromboembolism in patients with LVNC. The LAD may be a useful predictor for thrombotic risk stratification among such patients.