Risk Factors For Ischemic Stroke In Patients With Non-valvular Atrial Fibrillation

Background: It is important to study the risk factors of ischemic stroke in patients with AF and to conduct risk stratification of ischemic stroke.With the change of disease spectrum,the incidence of rheumatic valvular atrial fibrillation(AF)decreased year by year,ischemic stroke caused by non-valvular AF caused more and more attention.It is important to study the risk factors of ischemic stroke in patients with AF and to conduct risk stratification of ischemic stroke.Objective: The aim of this study was to investigate the risk factors of ischemic stroke in patients with non-valvular AF,and to analyze the independent risk factors and the predictive ability of the combined predictive model for ischemic stroke in AF patients.Methods: A total of 370 newly diagnosed patients with non-valvular AF who were admitted to Northern People’s Hospital from January 1st,2017 to December 31 st,2018 were selected.Patients were divided into control group(205 cases)and stroke group(165 cases).Clinical characteristics,laboratory data and echocardiography test results were compared between two groups.The risk factors for AF were analyzed by logistic regression.Then the receiver operating characteristic(ROC)curve was drawn to evaluate the predictive value of these risk factors.Besides,the predictive value of combined prediction model,like CHA2D2S2-VASC score combined with MPV or D2 was studied.Results: 1.The mean age of stroke group was(71.58 ~ 6.24)years old,which was higher than that of control Group(65.40 ~ 9.48)years old(p < 0.001).Compared with the control group,the stroke group had a a higher proportion of previous history of heart failure,hypertension,diabetes,stroke or transient ischemic stroke(TIA)and vascular disease(p < 0.05).The level of red blood cell distribution(RDW),white blood cell count(WBC),mean platelet volume(MPV),platelet distribution width(PDW),D dimer(D2),left atrial diameter(LAD),neutrophil count absolute value/lymphocyte ratio(NLR),CHADS2 and CHA2DS2-VASC score in stroke group were higher than that in the control group,while the level of mean corpuscular volume(MCV)and serum creatinine(CR)were lower in the stroke group(p < 0.05).There was no significant difference in other clinical data.2.Multivariate logistic regression analysis showed that CHA2DS2-VASc(OR = 2.154;95% CI,1.739-2.668;P < 0.001),MPV level(OR = 1.962;95% CI,1.493-2.579;P < 0.001)and D2(OR = 1.230;95% CI,1.09-1.498;P = 0.04)were significantly associated with ischemic stroke in patients with AF.3.Further,patients were divided into three groups according to the tertiles of MPV and D2.The results showed that there were significant differences in stroke rates among subgroups(p < 0.001).The incidence of stroke in AF patients with MPV≥12.2 fl and D2≥0.82 mg/L was 56.9% and 59.3% respectively,while the incidence of stroke in AF patients with MPV < 11.2 fl and D2 < 0.33 mg / L was 30.3% and 30.3% respectively,the incidence of stroke in high value group was higher than that in low value group(p < 0.05).According to the score of CHA2DS2-VASC,AF patients were divided into three groups: low-risk group: CHA2DS2-VASC=0,medium-risk group: CHA2DS2-VASC =1,high-risk group: CHA2DS2-VASC ≥2.The results showed that the incidence of stroke in AF patients gradually increased with the increase of stroke risk grade(0 vs 26.3% vs 53.3%),the difference was statistically significant(p < 0.05).4.The receiver operating characteristic(ROC)curve analysis showed that the area under the curve(AUC)of the ischemic stroke in patients with AF predicted by CHA2DS2-VASc,CHADS2,D2,and MPV was 0.761,0.749,0.668,and 0.664,respectively.A value of 3.5 for the CHA2DS2-VASc score ascertained with ROC curve analysis to predict ischemic stroke was found to have a sensitivity of 52.1% and specificity of 87.3%,while the cutoff value of CHADS2 score was 1.5 with a sensitivity of 63.0% and specificity of 78.5%.A value of 0.485 mg/L for the D2 ascertained with ROC curve analysis to predict ischemic stroke was found to have a sensitivity of 68.5% and specificity of 63.8%,while the cutoff value of MPV was 11.65 fl with a sensitivity of 67.3% and specificity of 58.5%.5.The combined predictive model analysis showed that: the AUC of the ischemic stroke in patients with AF predicted by CHA2DS2-VASc+MPV+D2,CHA2DS2-VASc+MPV,and CHA2DS2-VASc+D2 was 0.816,0.812 and 0.783,respectively.The prediction ability of the three combined models was stronger than that of CHA2DS2-VASC(p < 0.05).However,there was no statistical difference between CHA2DS2-VASC+MPV+D2 and CHA2DS2-VASC+MPV,CHA2DS2-VASC+MPV and CHA2DS2-VASC+D2.The cutoff value of CHA2DS2-VASC + MPV prediction model was 13.412,the prediction sensitivity and specificity were 72.1% and 81.5% respectively.Conclusions: 1.CHA2DS2-VASC,CHADS2,MPV and D2 were the independent risk factors for ischemic stroke in patients with AF,they are valuable in predicting the occurrence of AF related ischemic stroke.2.The predictive value of CHA2D2S2-VASc+MPV+D2,CHA2D2S2-VASc+MPV and CHA2D2S2-VASc+D2 were better than CHA2D2S2-VASc alone.More AF patients with stroke risk could be screened by these combined prediction models,thus,the secondary prevention of stroke could be carried out according to the actual situation of the patients in order to minimize the occurrence of stroke events.3.Considering to the clinical application,CHA2D2S2-VASC+MPV could be expected to be a powerful tool for further screening AF patients with truly low stroke risk.