The Predicting Value Of Two-Dimensional Speckle Imaging In The Long-Term Recurrence Of Atrial Fibrillationafter Catheter Ablation

Objective: To investigate the correlation between left atrial strain parameters based on two-dimensional speckle tracking imaging(2DSTI)and atrial fibrillation long-term recurrence after catheter ablation(CA),and reveal the clinical value of baseline global left atrial longitudinal strain(GLAS)in predicting the atrial fibrillation recurrence(AFR)after CA.This will be helpful for preoperative selection of patients and improve the procedure scheme,thus effectively reduces the AFR rate postoperatively.To assess the left atrial(LA)and right atrial(RA)function and compare the dissimilarities of LA and RA function in normal subjects using twodimensional speckle tracking imaging(2DSTI),which therefore provides the reference value to further study the atrial function in different pathological conditions.To evaluate the baseline left atrial strain in patients with atrial fibrillation(AF)before initial CA using 2DSTI technology.After 12-months follow-up,the relationship between the baseline clinical data,conventional echocardiography indicators,strain parameters and long-term AFR after CA were analyzed to explore the most powerful predictor in the recurrence of AF.Methods: A total of 98 healthy subjects who underwent echocardiographic examination were enrolled in our hospital during May 2015 to Jan 2016.All participants underwent transthoracic echocardiography(TTE)and conventional echocardiographic parameters were measured.2D images were taken from the apical four and twochamber views,and analyzed offline using the TomTec software in Echo workstation to evaluate atrial stain and strain rate parameters,including the global peak longitudinal atrial strain(GLAS)during ventricular systole,the Spos during early diastole and Sneg during late diastole.In line to these,the strain rate parameters such as SRs,SRe,Sra,respectively were measured.Atrial volume parameters such as atrial maximum volume(AVmax),atrial pre-contraction volume(AVp)and minimum atrial volume(AVmin)were also measured.The differences between LA and RA volume and strain parameters were then compared.A total of 115 consecutive AF patients(age 63.69±7.12 years,60.9% male)who successfully underwent CA for the first-time in our hospital department of Cardiology were recruited between Mar 2013 and Sep 2015.The related clinical data and laboratory indicators were measured.All patients were performed TTE and transesophageal echocardiography(TEE)before CA,preserved dynamic 2D gray scale images were analyzed off-line to derive the LA stain and strain rate parameters.All patients were followedup for one year after CA and the condition of AFR were recorded.Cox proportional hazards regression analysis was used to analyze the best predictors in the long-term risk of AFR after CA.Results: 1.Comparison of atrial volume parameters: LA Vmax,reservoir function parameters(filling volume,expansion index and diastolic emptying index)and conduit function parameters(passive emptying index)were significantly higher when compared to the RA above parameters(all P<0.01).2.Comparative analysis of deformation parameters showed that the GLAS,Spos,Sneg of RA were significantly larger than LA in the above described parameters,and the difference was statistically significant(all P<0.01).3.Correlation analysis of atrial strain parameters and clinical indicators: The LA of GLAS was negatively correlated with age,LADmax and LAVImax(all P<0.05),whereas positively correlated with E/A,LA expansion index and passive emptying index.However,the GLAS of RA was negatively correlated only with age,but no significant correlation with other parameters was observed(P>0.05).After 12-month follow-up,of the 62 persistent AF patients,22(35.5%)presented with AFR,and of the 53 paroxysmal AF,15(28.3%)had recurrent AF.1.Comparison of deformation analysis: Compared to patients without AFR,patients with AFR presented significantly impaired GLAS in both persistent as well as paroxysmal AF(P<0.05).Furthermore,persistent AF patients with AFR demonstrated a significantly higher LAVImax and ProBNP level,however,paroxysmal AF patients with AFR only demonstrated ProBNP levels higher than the maintenance sinus rhythm(P<0.05).2.Cox proportional-hazards regression analysis demonstrated that GLAS was an independent predictor of AFR after CA in both paroxysmal AF(HR=0.814,95% CI:(0.709-0.935),P=0.004)and persistent AF(HR=0.787,95%CI:(0.689-0.899),P<0.001),and the risk of AFR was significantly increased in patients with worse baseline GLAS.3.Comparison of ROC curves demonstrated that GLAS was the best indicator for predicting the AF recurrence after CA in both the paroxysmal(AUC value was 0.94,the cutoff value was 25.8%,with 93% sensitivity and 86% specificity)and persistent AF(AUC value was 0.86,the cutoff value was 23.6%,with 100% sensitivity and 58% specificity).4.The demographic data,complications,cardiovascular drugs and laboratory indicators demonstrated no statistically significant differences between the paroxysmal and persistent AF groups(all P<0.05).4.Analysis of conventional echocardiographic parameters demonstrated that persistent AF group had larger LA diameter and LAVImax than paroxysmal AF.However,there were no statistically significant differences in other echocardiographic parameters between the two groups.Conclusions:(1)2DSTI could accurately evaluate the functions of LA and RA,and dissimilarities existed in both the atria of healthy subjects.(2)Baseline GLAS was considered as an independent indicator for predicting the risk of AFR in patients with paroxysmal and persistent AF.Impaired GLAS was associated with high risk of AF recurrence after CA.This parameter may in turn help to improve the therapeutic strategies,and thus reduce the AF recurrence rate.