Analysis Of The Risk Factors Of Thrombotic Events In CHA₂DS₂-VASc=0 Patients With Nonvalvular Atrial Fibrillation

Objective:Atrial fibrillation（AF）is an independent risk factor for thromboembolic events,and nonvalvular atrial fibrillation（NVAF）increases the risk of stroke by 5.6 times.Therefore,the anticoagulant therapy is particularly important.2016 ESC Atrial Fibrillation Management recommend that assessment of the risk of thrombosis in patients with NVAF should be based on the CHA₂DS₂-VASc scoring system.In the guidelines,patients with nonvalvular atrial fibrillation and CHA₂DS₂-VASc score of 0were not necessary to take antithrombotic therapy.So far,most researches suggest that the risk of thrombosis in patients with CHA₂DS₂-VASc Score of 0 is low,and the anticoagulation therapy is not recommended.However,in recent years,some researches found that CHA₂DS₂-VASc system for atrial fibrillation patients to assessment the risk of thrombus events is not complete,there are still other clinical factors affect the incidence of thrombotic events and stroke.With this retrospectively analyzed study,we wanted to investigate the risk factors of thrombotic events in patients with nonvalvular atrial fibrillation with CHA₂DS₂-VASc score of 0,to discuss its intrinsic relationship,and to help to make choose in clinical practice.Methods:Collected continuously patients with non-valvular atrial fibrillation of CHA₂DS₂-VASc score of 0,who were admitted to the Second Affiliated Hospital of Nanchang University from 01.01.2009 to 12.31.2016.After eliminating patients with manual valve replacement or repair,hyperthyroidism,and hypertrophic cardiomyopathy and patients with incomplete data,there were 672 cases.Grouped according to thrombotic events,81 cases in the thrombosis group（male:61cases,female:20 cases）and 591 cases in the non-thrombotic events group（male:408cases,female:183 cases）.We collected the general clinical datas of 672 patients including:gender,age,history of hyperlipidemia,smoking history,drinking history;and the systolic blood pressure,diastolic blood pressure,heart rate and urinary protein positive rate on admission.We collected the patient’s data of venous blood that collected in the morning at the second day of admission,including:Routine blood[white blood cell count（WBC）,red blood cell count（RBC）,hemoglobin（HGB）,platelet count（PLT）,neutrophil percentage（N）,neutrophils absolute value（NEUT）,lymphocyte percentage（L）,lymphocyte absolute value（LYM）,neutrophil and lymphocyte ratio（NLR）,hematocrit（HCT）,mean corpuscular volume（MCV）,red blood Cell distribution width（RDW-CV）,red blood Cell distribution width（RDW-SD）,platelet hematocrit（PCT）,mean platelet volume（MPV）,platelet distribution width（PDW）];BNP,renal function[creatinine（Cre）,estimated glomerular filtration rate（eGFR）,uric acid（UA）];liver function[albumin（ALB）,aspartate aminotransferase（AST）,alanine aminotransferase（ALT）];blood fat[(total cholesterol（TC）,triglyceride（TG）,high density lipoprotein（HDL）,low density lipoprotein（LDL）,lipoprotein（a）（LP（a））];homocysteine（HCY）,c-reactive protein（CRP）,erythrocyte sedimentation rate（ESR）;All patients were performed echocardiography,and we collected the data:left atrium diameter（LAD）,right atrium diameter（RAD）,left ventricular end diastolic diameter（LVEDD）,left ventricular end systolic diameter（LVESD）,interventricular septal thickness（IVST）,and left ventricular ejection fraction（LVEF）.We wanted to investigate the characteristics of non-valvular atrial fibrillation patients with CHA2DS2-VASc score of 0 and to analyze the risk factors of thrombosis events in these patients.Statistical analysis was performed using SPSS,version.17.0.The measurement data was described with mean±standard deviation（?x±s）;Two independent samples were compared using independent sample t-test;Binary classification variables data was described with chi-square test.P values<0.05（two-sided）were considered statistically significant.Result:1.Of the 672 patients enrolled,the average age was 55±8 years old,and 469cases were male,203 cases were female;there were 81 cases in the thrombosis group,the incidence was 12%,and 591 cases in the non-thrombotic events group.2.Compared with the non-thrombotic events group,there was no significant difference in the history of systolic blood pressure,heart rate,history of hyperlipidemia,smoking history and drinking history（P>0.05）.3.Between with the two groups,there were no significant differences in RBC、HGB、PLT、LYM、HCT、MCV、RDW-CV、RDW-SD、PCT、MPV、PDW、BNP、Cre、eGFR、UA、ALB、AST、ALT、TC、TG、HDL、LDL、CRP、ESR、RAD、LVEDD、LVESD、and IVST.4.Compared with the non-thrombotic events group,the urinary protein positive rate,diastolic blood pressure,white blood cell count,neutrophil percentage,neutrophil absolute value,neutrophils/lymphocytes,lipoprotein（a）,homocysteine,and left atrium diameter were significantly higher in the thrombosis group（P<0.05）.However,the lymphocyte percentage and left ventricular ejection fraction were Obviously lower than those of the non-thrombotic events group（P<0.05）.5.Multiariable logistic regression analysis and ROC working curve showed that high serum lipoprotein（a）level（Lp（a）≥27.2mg/dL）and enlarged left atrial dilatation（LAD≥43.5mm）are thrombosis risk factors for nonvalvular atrial fibrillation patients with CHA₂DS₂-VASc score of 0[OR=1.02,95%CI（1.01-1.03）,P<0.01];[OR=1.13,95%CI（1.08-1.17）,P<0.01].Conclusion:High serum lipoprotein（a）level（Lp（a）≥27.2mg/dL）and enlarged left atrial dilatation（LAD≥43.5mm）are thrombosis risk factors for nonvalvular atrial fibrillation patients with CHA₂DS₂-VASc score of 0.