Background: Left atrial spontaneous echo contrast (LASEC) is common in patients with atrial fibrillation (AF), although scarce information exists regarding LASEC occurring in AF patients with low thromboembolic risk scores. We investigated prevalence and determinants of LASEC under low CHADS 2 or CHA 2 DS 2 -VASc scores.
Methods: Among 713 patients with nonvalvular AF who underwent transesophageal echocardiography, 361 with a CHADS 2 score <2 (CHADS 2 group) and 227 with a CHA 2 DS 2 -VASc score <2 (CHA 2 DS 2 -VASc group) were separately examined for clinical and echocardiographic findings.
Results: LASEC was found in 80 patients of CHADS 2 group (22%) and in 44 of CHA 2 DS 2 -VASc group (19%). With multivariate logistic regression analysis, adjusted for non-paroxysmal AF, renal dysfunction, LA diameter ≥50 mm, left ventricular (LV) ejection fraction <50%, LV hypertrophy, and B-type natriuretic peptide (BNP) ≥200 pg/mL, it was demonstrated that for CHADS 2 group, “non-paroxysmal AF” (OR 5.86, 95%CI 3.21-10.7, P <0.001), BNP ≥200 pg/mL (Odds ratio 3.22, 95%CI 1.25-8.28, P = 0.015), and LV hypertrophy (Odds ratio 2.16, 95%CI 1.11-4.20, P = 0.024) were significant independent determinants of LASEC, and that for CHA 2 DS 2 -VASc group, “non-paroxysmal AF” (Odds ratio 3.42, 95%CI 1.53-7.65, P = 0.002) was a significant independent determinant of LASEC.
Conclusions: LASEC was present in a considerable proportion of patients who had low CHADS 2 or CHA 2 DS 2 -VASc scores. Information on chronicity of AF, BNP, and LV hypertrophy may help identify patients at risk for thromboembolism.