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. 2022 Jan 25;4(1):42-53.
doi: 10.36628/ijhf.2021.0043. eCollection 2022 Jan.

Left Atrial Dysfunction, Fibrosis and the Risk of Thromboembolism in Patients With Paroxysmal and Persistent Atrial Fibrillation

Hee-Dong Kim  1 , Dong-Hyuk Cho  2 , Mi-Na Kim  3 , Sung Ho Hwang  4 , Jaemin Shim  3 , Jong-Il Choi  3 , Young-Hoon Kim  3 , Seong-Mi Park  3
Affiliations

Left Atrial Dysfunction, Fibrosis and the Risk of Thromboembolism in Patients With Paroxysmal and Persistent Atrial Fibrillation

Hee-Dong Kim et al. Int J Heart Fail. .

Abstract

Background and objectives: Left atrial (LA) fibrosis is an important component of the arrhythmogenic substrate and is related to LA dysfunction in patients with atrial fibrillation (AF). However, its relationship with functional changes and the risk of thrombus in patients with paroxysmal AF (PAF) and persistent AF (PeAF) remains unclear.

Methods: We included 139 patients with preprocedural cardiac magnetic resonance imaging (CMR) and transesophageal echocardiography (TEE) for the first AF catheter ablation. Spontaneous echo contrast (SEC) and multiple parameters of LA were measured from TEE and CMR. LA fibrosis was evaluated by late gadolinium enhancement of LA (LA-LGE) of CMR.

Results: The presence of SEC was higher in patients with PeAF than in patients with PAF (26.4% vs. 11.9%, p=0.03). The patients with SEC had more enlarged LA size and impaired function of LA and LAA, regardless of AF type. However, the area of LA-LGE was more extensive in patients with SEC in PeAF (27.5±15.9 vs. 20.1±10.3, p=0.033), not in PAF. In PAF, maximal LA volume index was closely related to the presence of SEC with marginal trend toward significance (odd ratio [OR], 1.07; 95% confidence interval [CI], 0.99-1.16; p=0.072). Whereas, a larger area of LA-LGE and lower emptying flux of LA appendage were independently related with SEC (OR, 1.10; 95% CI, 1.0-1.20; p=0.049 and OR, 0.93; 95% CI, 0.86-0.99; p=0.022, respectively) after adjusting related cardiovascular risk factors of SEC.

Conclusions: In this study, we suggest that the risk of thrombus is provoked by LA enlargement with dysfunction in early-stage AF and by stiffened LA with fibrosis rather than LA size when it becomes PeAF.

Keywords: Atrial fibrillation; Left atrial function; Spontaneous echo contrast.

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Conflict of interest statement

Conflict of Interest: The authors have no financial conflicts of interest.

Figures

Figure 1
Figure 1. Differences in LA functional parameters between AF patients with or without the presence of SEC.
AF = atrial fibrillation; LA = left atrial; LA-LGE = left atrial late gadolinium enhancement ; LAEF = left atrial emptying fraction; LAV = left atrial volume; SEC = spontaneous echo contrast.
Figure 2
Figure 2. Plots for odds ratios in the presence or absence of SEC; final model with multivariate analysis.
LA-LGE = left atrial late gadolinium enhancement; LAA-EF = emptying flux of left atrial appendage; LAEF = left atrial emptying fraction; LAVImax = maximal left atrial volume index; SEC = spontaneous echo contrast. *p<0.05, **p<0.01.
Figure 3
Figure 3. Postulated relationship between LA dysfunction and fibrosis and the risk of thromboembolism in patients with AF. Persistent AF leads to AF and more LA fibrosis. SEC and the risk of thromboembolism is increased by LA dysfunction and LA fibrosis.
AF = atrial fibrillation; LA = left atrial; SEC = spontaneous echo contrast.
See this image and copyright information in PMC

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