Clinical significance of echocardiographic left ventricular hypertrophy for predicting left atrial appendage thrombotic milieu in patients with atrial fibrillation and CHA2DS2-VASc scores of 0-2
Authors: Minami K , Machino-Otsuka T , Nakatsukasa T , Kawamatsu N , Sato K , Yamamoto M , Yamasaki H , Ishizu T 
Published: October 2024

Abstract

Background
Even in patients with atrial fibrillation (AF) and low CHA2DS2-VASc scores, it is not always possible to completely rule out left atrial appendage (LAA) thrombus. Further stratification of the risk of LAA thrombosis in these patients remains an important yet unresolved issue. Left ventricular hypertrophy (LVH) is a prognostic risk factor in AF and has been associated with a worse prognosis, particularly in those with low CHA2DS2-VASc scores.

Purpose
To investigate the clinical significance of echocardiographic LVH for risk stratifying LAA thrombogenic milieu as a surrogate for cardioembolic risk in patients with AF and CHA2DS2-VASc scores of 0–2.

Methods
This was a single-center, retrospective study. We enrolled 707 consecutive patients with AF and CHA2DS2-VASc scores of 0–2 who underwent transesophageal echocardiography. The patients were divided into two groups based on the presence or absence of LVH. Owing to the racial differences in normative left ventricular mass index (LVMI) reference values, LVH was defined in this study using Japanese reference values. LVH was defined as LVMI ≥108 g/m2 for men and ≥98 g/m2 for women. LAA thrombogenic milieu was defined by any of the following findings: (1) thrombus, (2) severe spontaneous echo contrast or sludge, or (3) average LAA flow velocity ≤20 cm/s. Alongside conventional parameters, longitudinal strain values for the left ventricle (LV) and left atrium (LA) were obtained using transthoracic echocardiography.

Results
The mean age was 61 ± 10 years, and 12.2% were female. Overall, 77 (10.9%) patients were classified into the LVH group, and 41 (5.8%) of patients had LAA thrombogenic milieu. The LVH group exhibited a significantly higher prevalence of LAA thrombogenic milieu than the non-LVH (32.5% vs. 2.5%, p&lt;0.001). Figure 1 illustrates the details of the patients with the LAA thrombogenic milieu based on LVH presence and CHA2DS2-VASc scores. The LVH group included six patients with LAA thrombus, even with CHA2DS2-VASc scores of 2, whereas the non-LVH group had no patient with LAA thrombus. Table shows the association of LAA thrombogenic milieu and clinical and echocardiographic parameters by logistic regression analysis; LVH independently associated with LAA thrombogenic milieu after adjusting for clinical factors (including CHA2DS2-VASc score, AF type, and serum brain natriuretic peptide levels) and conventional echocardiographic parameters (including LV ejection fraction, LV end-diastolic volume index, and LA volume index). Moreover, LVH provided incremental prognostic value for predicting LAA thrombogenic milieu, even when added to the longitudinal strain of the LV and LA reservoir strains (p&lt;0.001). These findings are summarized in Figure 2.

Conclusion
Echocardiographic LVH significantly improves the prediction of LAA thrombogenic milieu, offering potential utility in further cardioembolic risk stratification for patients with AF and CHA2DS2-VASc scores of 0–2.