Clinical characteristics of left atrial appendage thrombus in patients with hypertrophic cardiomyopathy and non-valvular atrial fibrillation

Abstract

Objective: To investigate the incidence and clinical characteristics of left atrial appendage (LAA) thrombus in patients with hypertrophic cardiomyopathy (HCM) and non-valvular atrial fibrillation (AF) . Methods: Data from 10 440 patients with AF who had undergone transesophageal echocardiography (TEE) before cardioversion or catheter ablation at Beijing Anzhen Hospital from April 2006 to December 2018 were retrospectively screened. Two hundred and five HCM patients were included, 820 AF patients with the same CHA(2)DS(2)-VASc score over the same period were selected as the control group. HCM patients were divided into two subgroups based on presence or absence of LAA thrombus/sludge. The baseline of clinical information, transthoracic echocardiographic and TEE measures were compared among all the groups. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of left atrial diameter (LAD) for LAA thrombus/sludge. Multivariate logistic regression analysis was applied to analyze the correlative factors of LAA thrombus/sludge in HCM patients. Results: The incidences of LAA thrombus or sludge were higher in HCM group than in control group (10.7% (22/205) vs. 0.7% (6/820); 8.8% (18/205) vs.7.0% (57/820), P<0.001) . In HCM patients, LAD was significantly larger in LAA thrombus/sludge subjects than in those without thrombus/sludge ((48.9±5.1)mm vs. (45.2±6.1) mm, P<0.001). CHA(2)DS(2)-VASc score was similar between the two subgroups ((2.0±1.4) vs. (1.8±1.4), P>0.05). There was no difference in the rate of patients with a CHA(2)DS(2)-VASc scores ≥2 between the subgroups(62.5% (25/40) vs. 57.0% (94/165), P=0.525). The incidences of LAA thrombus in HCM and AF patients with CHA(2)DS(2)-VASc scores of 0, 1 and 2 were 8.8% (3/34) , 9.6% (5/52) , 11.8% (11/119) , respectively; and the rate of LAA sludge were 8.8% (3/52) , 7.7% (4/52) , 9.2% (11/119) , respectively. The cut off value of LAD for the diagnosis of LAA thrombus/sludge was 44.5 mm. Multivariate logistic regression analysis showed that LAD≥44.5 mm (OR=5.134, 95%CI 1.862-14.156, P=0.002) , non-paroxysmal AF (OR=2.782, 95%CI 1.238-6.252, P=0.013) , previous thromboembolism or stroke (OR=1.820, 95%CI 0.774-4.227, P=0.017) were independent determinants of LAA thrombus/sludge. Conclusions: The incidence of LAA thrombus/sludge is higher in patients with HCM and AF than in AF patients without HCM. The CHA(2)DS(2)-VASc score is similar between HCM and AF patients with LAA thrombus/sludge and those without thrombus/sludge. Patients with CHA(2)DS(2)-VASc score 0-1 are also likely to suffer LAA thrombus/sludge. Left atrial enlargement is associated with LAA thrombus/sludge.