Risk Prediction Model Of Ischemic Stroke In Patients With Low-risk Non-valvular Atrial Fibrillation

Objectives:Atrial fibrillation（AF）is a common serious arrhythmia in clinical practice,which is prone to cause a variety of complications.Ischemic stroke（IS）is the most serious complication.Patients with atrial fibrillation have a five-fold increased risk of stroke compared with patients without atrial fibrillation.Anticoagulation is the main strategy for preventing stroke,clinical guidelines recommend that patients with non-valvular atrial fibrillation（NVAF）with a CHA₂DS₂-VASc score of≥2 for men or≥3 for women need anticoagulation to prevent stroke events.The anticoagulation in low-risk patients（CHA₂DS₂-VASc score≤1 for men or≤2 for women）remains controversial because of the net clinical benefit of anticoagulation in low-risk patients is different in several studies,but stroke can still occur in these patients.Therefore,in order to identify low-risk patients who are prone to ischemic stroke,a risk prediction model will be constructed to provide a basis for clinical decision-making and benefit patients.Methods:The research subjects were inpatients from the neurology department and cardiology department of the first affiliated hospital of nanchang university.Eligible patients were screened in strict accordance with the inclusion and exclusion criteria and divided into a modeling group and an internal verification group.The clinical data of the patients were retrospectively collected,and the clinical characteristics of the patients were described in the modeling group and the validation group.Firstly,univariate and multivariate logistic regression analysis was used to screen independent risk factors for stroke in the modeling group.And a predictive model was constructed based on these independent risk factors,then validated in the validation group and evaluated for its discriminating ability,calibration ability,and clinical effectiveness,and finally draw a nomogram to visualize the predictive model.Results:1.Four predictors were filtered out by logistic regression analysis:persistent atrial fibrillation（OR=2.996,95%CI:1.052-8.529,P=0.040）,Neutrophil-lymphocyte ratio（NLR）（OR=1.433,95%CI:1.196-1.718,P<0.001）,Homocysteine（Hcy）（OR=1.319,95%CI:1.130-1.540,P<0.001）,Left atrial diameter（LAD）（OR=1.167,95%CI:1.061-1.284,P=0.002）.2.A risk prediction model was constructed based on the four predictors obtained by multivariate logistic regression analysis,and verified and evaluated.The model evaluation results showed that the Area Under the Curve（AUC）of the modeling group was 0.905（95%CI:0.857-0.953）with a sensitivity of 74.3%and a specificity of 92.9%,and the AUC of the validation group was 0.852（95%CI:0.753-0.951）with a sensitivity of 86.7%and a specificity of 73.3%,and both groups passed the Hosmer-Lemeshow test,The clinical utility evaluation shows that the model has a clinical net benefit.Conclusions:1.Persistent atrial fibrillation,NLR,Hcy and LAD are independent risk factors for IS in patients with low-risk NVAF.2.Based on four independent risk factors,a risk prediction model for IS in low-risk NVAF patients was constructed:Probability=1/（1+exp（-（-11.134+1.097×AF type+0.36×NLR+0.277×Hcy+0.154×LAD）））.3.The prediction models were verified and evaluated respectively,which proved that the prediction model has good clinical application value and can provide an important scientific basis for clinical decision-making.The drawn nomogram also allows clinicians to more easily and quickly assess the risk of stroke in patients with NVAF.