Thrombosis of the Left Atrial Appendage and Thromboembolic Events in Patients with Atrial Fibrillation: Clinical and Instrumental Correlates

Mari G. Arakelyan, Elena Z. Golukhova, Olga I. Gromova, Naida I. Bulaeva, Tatiana V. Mashina, Violetta S. Dzhanketova, Aygerim Z. Zholbaeva, Maria A. Shlyappo

A.N. Bakoulev Scientific Center for Cardiovascular Surgery, Moscow, Russia

Date, time and location: 2018.05.25 13:30, Exhibition area, 1st Floor. Zone – A

Abstract

Background. Atrial fibrillation (AF) is associated with a high risk for thromboembolic events. The

CHA 2 DS 2 VASc risk scale is very reliable, but has some limitations. Thromboembolism can occasionally

occur even in patients with AF with low CHA 2 DS 2 VASc score.

Purpose. Identification of clinical and instrumental parameters influencing the formation of

thrombosis of the left atrial appendage (LAA) and the development of thromboembolic events

in patients with atrial fibrillation without concomitant coronary artery disease and valvular

disease.

Methods. The retrospective analysis included 112 patients with AF who were hospitalized to

Bakoulev Centre of cardiovascular surgery between 2012 and 2015 for radiofrequency ablation

(RFA). All patients had proper anticoagulation. All patients underwent transthoracic

echocardiography. Contrast-enhanced computed tomography (CT) of LA was performed in 105

patients (87%) to reveal of pulmonary veins abnormality and definition one of three

morphological types of LAA. Transesophageal Echocardiography (TEE) was performed in 47

(39%) patients with calculation of left atrial appendage (LAA) blood velocity and identification

of spontaneous ECHO contrast. Fourteen patients (12%) had LAA thrombosis by TEE or CT

and/or thromboembolic (TE) complications in anamnesis (ischemic stroke or TIA).

Results. The following clinical parameters were significantly associated with LAA thrombosis

and/or ischemic stroke or TIA in anamnesis: age older than 65 years (p=0.001), obesity

(p=0.036), chronic AF (risk increases proportionally from paroxysmal to permanent type)

(p=0.003) and CHA 2 DS 2 VASc risk score (p=0,005). The following TEE parameters had predictive

value: low LAA blood flow (<30cm/s) (p=0.001), the spontaneous ECHO contrast (p=0.03).

According to CT the morphological LAA type III had a predictive value (p=0.01).

Conclusion. Thus, in addition to traditional risk factors, such as CHA 2 DS 2 VASc scale, we

identified novel predictors of LA thrombosis and/or TE events, which are: obesity, chronic AF,

low LAA blood flow velocity, the phenomenon of spontaneous ECHO contrast in LA and the

morphological LAA type III by CT.