Clinical Significance Of Serum SST2 Level In Patients With Non-valvular Atrial Fibrillation

Objective:The purpose of the study was two fold,firstly,to observe the level of Serum Suppression of Tumorigenicity 2(sST2)protein in serum of patients with non-valvular atrial fibrillation,secondly,to explore its relationship among myocardial fibrosis and atrial fibrillation recurrence after radiofrequency ablation.The serum marker may provide a possible reference indicator for the clinical preoperative assessment of atrial fibrosis and the prediction of the progression of atrial fibrillation.Methods:1.Research objects: Fifty-one patients with paroxysmal atrial fibrillation who were clinically diagnosed and divided into arrhythmia recurrence group and non-recurrence group according to the clinical outcome after 9 months of follow-up.The recurrence group was defined as the recurrence of atrial arrhythmia(atrial fibrillation/ atrial tachycardia/ atrial flutter/ atrial premature beats)with a duration of more than 30 seconds after a single operation with anti-arrhythmic drugs stopped.2.Data and blood sample collection: Collecting general clinical data,relevant laboratory indicators,and imaging data of patients with atrial fibrillation,collecting serum sST2 and peripheral blood samples before surgery,and measuring serum sST2 concentration by ELISA kit.3.Atrial fibrillation outcome score: The risk of preoperative paroxysmal atrial fibrillation was divided into HATCH score 0 group and HATCH score 1 group based on the estimation of HATCH score.4.Calculating the proportion of the left atrium low-voltage area: During the operation,Ensite Velocity system and CARTO system three-dimensional electromagnetic catheter was positioned to establish a three-dimensional model of the left atrium,the total left atrium area was calculated as the sum of the anterior wall,inferior wall,bilateral walls,and posterior wall.According to the selection criteria(health area: >0.5 mV,border area: 0.25–0.5 mV and scar area: <0.25 mV),the left atrial collection points were classified.Define the low voltage zone(Atrial low-voltage zones,LVZ)as an area <0.5mv,calculate the LVZ range as a percentage of the left atrium surface area,divide the LVZ into phase I(<5%),phase II(5%-20%),Stage III(20%-30%),stage IV(>30%),and then assess the level of left atrial fibrosis.5.Statistical analysis: The statistical software SPSS22.0 was used to perform Shapiro-Wilk normality test on the baseline data of the two groups of patients.Besides,Independent sample t test,ANOVA analysis of variance,Mann-Whitney U test,and Chi-square test were applied respectively for determining whether the differences were statistically significant.Pearson correlation analysis was used to calculate the relationship between serum sST2 and the proportion of left atrium scar area.Multivariate logistic regression analysis was used to test the related factors of AF recurrence.The receiver operating characteristic curve was used to evaluate the predictive value of serum sST2 level in atrial fibrillation.Results:1.The sST2 level of 51 patients with atrial fibrillation was higher than that of 21 healthy people.There were different degrees of myocardial fibrosis in the left atrium of patients with atrial fibrillation.Serum sST2 in patients with LVZ stage IV was significantly higher than that in patients with LVZ stage I(P <0.05).2.Patients with different HATCH scores have different postoperative recurrence rates,and those with a HATCH score of 1 were significantly higher than the HATCH score of 0(P <0.05).3.Pearson correlation analysis showed that the serum sST2 level was positively correlated with the inner diameter of left atrium and the proportion of scar area(r were 0.325,0.778,P <0.05).4.Within 9 months follow-up,39 patients maintained sinus rhythm(76%),and12 patients relapsed(24%)without death.Compared with the non-recurrence group,the proportion of serum sST2 level,inner diameter of left atrium,and left atrial lowvoltage area were higher in the recurrence group,the differences were statistically significant(P <0.05).Volume,LVZ stage,and serum sST2 levels are risk factors for recurrence of atrial fibrillation.5.The receiver operating characteristic(ROC)curve showed that the area under the ROC curve of serum sST2 level predicting atrial fibrillation was 0.693(95% CI:0.521 to 0.865;P <0.05).Conclusion:To some extent,the serum sST2 level in patients with non-valvular atrial fibrillation can be used to assess the degree of left atrial myocardial fibrosis by reflecting the proportion of the left atrial low-voltage area,and at the same time estimate the risk of paroxysmal atrial fibrillation to persistent atrial fibrillation.It is also a reference indicator for measuring the recurrence of patients after radiofrequency ablation.