Assessment of left atrial appendage function by transthoracic echocardiography in non-valvular atrial fibrillation

Abstract

Background: Transesophageal echocardiography (TEE) is currently accepted for assessment of left atrial appendage (LAA) function in patients (pts) with non-valvular atrial fibrillation (AF). Yet, TEE might not be used for screening and follow-up purposes. Purpose: To evaluate spectral tissue Doppler imaging (TDI) parameter obtained by transthoracic echocardiography (TTE) to assess LAA function in pts with non-valvular AF. Methods: The study included 91 pts with non-valvular AF (mean age 61±10 ys; 60 men (65,9%) and 31 women (34,1%); 67 (73,6%) had concomitant hypertension, 27 (29,7%) - coronary artery disease, 65 (71,4%) – heart failure, 9 pts (9,9%) – history of stroke or transient ischemic attack). LAA apex movement velocity was measured by TTE TDI (Avel) and LAA ejection velocity (Evel) – by TEE. According to the value of Evel pts were divided into two groups: group 1 (G1) - Evel ≥30,0 cm/s, n = 63, and group 2 (G2) - Evel <30,0 cm/s, n = 28. The groups were comparable by gender and concomitant diseases. Data are expressed as median with range and 95% confidence intervals (CI). Results: It was found, that Avel was significantly lower in G2 than in G1 (6,0 (5,0-7,5) and 9,4 (8,1-11,1) cm/s, accordingly, p<0,001) and significantly related to Evel (Spearman's r= 0,57, p<0,001). Area under ROC-curve for Avel for discrimination G1 and G2 was 0,866 (0,788-0,944) with cut-off value 7,8 cm/s. The discrimination ability of Avel at this cut-off was as follows: sensitivity 81,8% (95% CI 59,7-94,8), specificity 80,7% (95% CI 68,1-90,0), positive predictive value 62,1% (95% CI 42,3-79,3) and negative predictive value 92,0% (95% CI 80,8-97,8). Conclusion: Avel measured by TTE might be used an alternative to Evel measured by TEE for assessment of LAA function in pts with AF.