Predictors of thrombosis of left atrium and its appendage before catheter ablation or cardioversion in patients with non-valvular atrial fibrillation or atrial flutter

Abstract

Aim. To determine the incidence of left atrial (LA) and/or LA appendage (LAA) thrombosis in patients with non-valvular atrial fibrillation (AF) (NAF) or atrial flutter (AFL) on transesophageal echocardiography (TEE) before elective catheter ablation (CA) or cardioversion (CV) and characterize the predictors of LA/LAA thrombosis among the indicators available in the routine practice of cardiologists and general practitioners.Material and methods. In this retrospective, single-center, casecontrol study, the medical records of 1994 patients with NAF or AFL for the period 2014-2019, who underwent TEE before CA or elective CV, were analyzed. A thrombus in the LA/LAA was detected in 33 (1,6%) of them. For the comparison group, 167 patients were randomly selected without LA/LAA thrombosis. Demographic, anamnestic and clinical parameters, transthoracic echocardiography data, and laboratory results were analyzed as potential predictors of LA/LAA thrombosis.Results. Patients with LA/LAA thrombosis were older (mean age, 64,8±1,6 vs 59,4±10,8 (p=0,01), more often had persistent or longstanding persistent AF, hypertension, heart failure, enlarged LA, lower left ventricular ejection fraction (LVEF) and estimated glomerular filtration rate, as well as more severe symptoms according to the modified European Heart Rhythm Association (EHRA) score and a higher CHA2DS2-VASc score (median, 4,0 vs 2,0; p=0,0001). Oral anticoagulants were taken by 88% of patients; there were no significant differences in the presence and composition of anticoagulant therapy between the groups. Functional class (FC) according to the modified EHRA score (odds ratio (OR), 5,4; 95% confidence interval (CI): 1,9814,96; p=0,001) and LVEF were independent predictors of LA/LAA thrombosis (OR, 0,87; 95% CI: 0,80-0,95; p=0,002). For EHRA class 3-4, the OR was 5,1; 95% CI: 2,3-11,4 (p<0,0001), for LVEF <48% — 7,4; 95% CI: 1,2-46,7 (p=0,03). For EHRA class 3-4, the sensitivity for LA/LAA thrombosis was 93,7%, specificity — 71,9%, positive predictive value — 50,0%, negative predictive value — 87,6%; for LVEF <48% — 66,7, 32,3, 31,9 and 91,6%, respectively.Conclusion. In the studied group of patients with NAF or AFL, without severe structural heart disease and severe concomitant diseases, most of whom received oral anticoagulants, LA/LAA thrombosis at TEE before elective CA or CV was detected in 1,6% of cases. Among the indicators available in routine medical practice, the severity of arrhythmia symptoms, assessed by the modified EHRA score, and lower LVEF were independent predictors of LA/LAA thrombosis.