Left Atrial Geometry Improves Risk Prediction of Thromboembolic Events in Patients With Atrial Fibrillation.

Abstract

Left atrial (LA) sphericity (LASP) is a new remodeling parameter based on LA shape analysis, with independent predictive value for recurrence after atrial fibrillation (AF) ablation. To evaluate the association between LASP and thromboembolic events (TE) in patients with AF. Twenty-nine AF patients and prior TE and 29 age- and gender-matched controls were included. LASP was calculated using a 3D-LA reconstruction. The LA appendage (LAA) volume and morphology were assessed. ROC curve analysis was performed for LASP, LA volume, LAA volume, and CHAD/CHA2 D-VASc scores (Stroke2 -the grouping variable-was excluded). Mean age of the study population was 61 ± 11 years (79.3% males, 53.4% hypertension, 8.6% diabetes). Patients with prior TE had higher LASP than those without (82.5 ± 3.3% vs. 80.2 ± 3.1%, P = 0.008); there were no differences in CHAD or CHA2 D-VASc scores, LA volume, LAA volume, or LAA morphology. The C-statistic was higher for LASP (0.71) than for other tested variables (CHAD score = 0.58, CHA2 D-VASc score = 0.59, LA volume = 0.50, LAA volume = 0.46; P < 0.01 for all vs. LASP). The best cutoff value for LASP was 83.6% (sensitivity 0.52, specificity 0.90). Logistic regression analysis showed predictive value for LASP (OR 1.26 per each 1% increase [1.85-52.20], P = 0.013), but not for clinical risk scores. The addition of LASP to the CHAD and CHA2 D-VASc scores increased the predictive value over the risk scores alone (P = 0.004), and reclassified 45.5% of patients with CHAD = 0 (no anticoagulation indicated) to moderate-risk (anticoagulation indicated). LA sphericity is associated with prior TE in AF patients and improves the performance of the CHAD and CHA2 D-VASc scores alone.