The Relationship Between High-density Lipoprotein Cholesterol And Left Atrial Thrombus In Nonvalvular Atrial Fibrillation Patients

BackgroundsAtrial fibrillation is the most comman abnormal cardiac rhythm,with population aging,the incidence rate of AF yearly increases.The persistently rapid and disordered cardiac impulse usually results in hemoclynamics and poor quality of life.AF is closely related to various of cardiovascular diseases,with coronary heart disease,hypertension,valvular heart disease,cardiac dysfunction concomitantly,all of them interact as both cause and effect,participate in or aggravate the initiation and development process of AF.The cerebral embolism and thromboembolic events due to the atrial thrombus falling off,have higher morbidity and mortality.The nonvalvular atrial fibrillation accounts for 65.2%,the incidence rate of which induced stroke is 5.3%,is 5.6 times than the normal occurred.More than 90% with left atrial thrombus come from the left atrial appendage,which is closely related to the special anatomy and function.TEE is usually used as routine examination before the radiofrequency ablation or electrical cardioversion in AF patients,which is the golden standard excluding atrial thrombus.As is known to all,dyslpidemia is an important reason of atherosclerosis and coronary heart disease（CHD）.High level of low-density lipoprotein cholesterol（LDL-C）and low level of high-density lipoprotein cholesterol（HDL-C）are directly related to the increased risk of CHD.Dyslpidemia as a risk factor for AF,the role of which is unclear in the process of its occurrence and development.In recent years,the relationship between dyslpidemia and AF becomes a new sport,attracting many scholars’ attention.The dates of the Multi-Ethnic Study of Atherosclerosis（MESA）and the Framingham Heart Study（FHS）show that high triglycerides and low-HDL is associated with an increased risk of AF.In a cohort study from Japan,Watanabe puted forward HDL-C reduce the risk of AF.In addition to the protect factor of atherosclerosis,HDL-C has an role of resist arteriovenous thrombosis.The studies about the protection function of HDL-C in stroke,pulmonary embolism and idiopathic venous thrombosis had been reported in succession.Wheres the study about the relationship between HDL-C and left atrial thrombus in nonvalvular atrial fibrillation patients is less,still needs more investigations.ObjectiveAnalysis the risk factors for left atrial thrombus in nonvalular atrial fibrillation patients,discuss the relationship between HDL-C and left atrial thrombus,and the predictive value of risk factors for atrial thrombus.MethodsWe retrospectively searched the echocardiology database at our department for all the patients with nonvalvular atrial fibrillation who underwent transesophageal echocardiography（TEE）examination prior to AF catheter ablation between January 2014 and April 2016,473 patients were included.The patients were divided into two groups according to the presence（n=60）or absence（n=413）of left atrial thrombus based on TEE results.General condition,CHA₂DS₂-VASc score,laboratory test results（HDL-C inculed）and echocardiographic measures of patients were recorded in detail,compared the difference between the two groups.Univariate and multivariate logistic regression analysis are in the indicators who are statistically significant difference and draw ROC curve to analysis the predictive value of risk factors for atrial thrombus.Results（1）Baseline data comparison between thrombus group and non-thrombus group: the age、stroke proportion、CHA₂DS₂-VASc score、non-persistent AF proportion、the RDW level、and LAD in the thrombus group are superior to the non-thrombus group,but HDL-C is opposite.（2）Univariate logistic regression analysis for left atrial thrombus formation: the older、stroke history、non-persistent AF、high CHA₂DS₂-VASc score and RDW level、LAD are risk factors for left atrial thrombus formation,but high level of HDL-C is a protect factor for left atrial thrombus formation.（3）Multivariate logistic regression analysis for left atrial thrombus formation: the high CHA₂DS₂-VASc score and non-persistent AF proportion are independent risk factors for left atrial thrombus formation,wheres the HDL-C is an independent protect factor.（4）The ROC curve of CHA₂DS₂-VASc score 、 HDL-C combined with CHA₂DS₂-VASc score and non-persistent AF:the AUC of CHA₂DS₂-VASc score to predict left atrial thrombus in nonvalvular atrial fibrillation patients was 0.717（95%CI:0.671-0.759,p < 0.001）,the AUC of HDL-C combined with CHA₂DS₂-VASc score and non-persistent AF was 0.791（95%CI:0.749-0.829,p<0.001）,the areas under the curve were statistically significant difference（p=0.012）.ConclusionsLow HDL-C level is a high risk factor for left atrial thrombus,combining HDL-C level with CHA₂DS₂-VASc score and non-persistent AF to predict left atrial thrombus in nonvalvular atrial fibrillation patients is superior to CHA₂DS₂-VASc score.