The Value Of Echocardiography In Evaluating Cardiac Function And Predicting Recurrence After Cryoballoon Catheter Ablation In Patients With Paroxysmal Atrial Fibrillation

Objective:Atrial fibrillation(AF)is a common clinical arrhythmia,paroxysmal atrial fibrillation(PAF)belongs to the early stage of AF progression.Assessment of cardiac structure and function in patients with PAF and timely intervention can prevent them from progression to persistent atrial fibrillation.At present,there are many clinical studies on left atrial structure and function in patients with PAF,but there are relatively few studies on left atrial electrical remodeling and ventricular function.However,left atrial electrical remodeling is closely related to the occurrence,development and prognosis of atrial fibrillation,and atrial fibrillation and heart failure are mutually causal.Therefore,it is of great clinical value to comprehensively evaluate the cardiac structure and function of PAF patients.Ischemic stroke is one of the most serious complications of atrial fibrillation and accurate prediction of its occurrence has important clinical significance.CHA₂DS₂-VAS_Cscore is recommended in the 2012 European Heart Rhythm Association consensus on catheter and surgical treatment of atrial fibrillation for the risk assessment of ischemic stroke in nonvalvular atrial fibrillation.Studies have shown that left atrial enlargement is associated with the risk of ischemic stroke in patients with atrial fibrillation,and can be used as a reference index for embolization risk stratification of CHA₂DS₂-VAS_C score.However,most PAF patients have no significant enlargement of the left atrium.Therefore,it is particularly important to comprehensively evaluate the cardiac structure and function by echocardiography in order to find echocardiographic parameters that can predict the risk of ischemic stroke in PAF patients.Cryoballoon catheter ablation(CBCA)is a new technique for the treatment of PAF,but there is still a high recurrence rate.Clinical guidelines have not recommended a scoring method for evaluating recurrence of AF after catheter ablation.CHA₂DS₂-VAS_C score,CAAP-AF score and BASE-AF₂ score are the scoring methods reported in the literature that can be used to evaluate the AF recurrence after catheter ablation,but whether they can be used to evaluate the PAF recurrence after CBCA remains unclear.In addition,the value of echocardiographic parameters in evaluating the recurrence of PAF patients after CBCA is not clear.Therefore,the purpose of this study is to comprehensively explore the application of echocardiography to assess the cardiac structure and function in patients with PAF and its predictive value for the risk of ischemic stroke.At the same time,to explore the predictive value of echocardiographic parameters for recurrence after CBCA,in order to provide important reference for clinical condition evaluation,treatment guidance and prognosis evaluation.Method:1.Research objects:146 patients with PAF who underwent CBCA in the Department of cardiovascular medicine of our hospital and 132 healthy controls in the same period were selected.(1)General clinical information:age,gender,comorbid diseases(hypertension,diabetes,coronary heart disease).(2)Blood biochemical parameters:blood lipid,blood glucose,uric acid,creatinine.2.Image acquisition and analysis:The patients underwent transthoracic echocardiography during sinus rhythm within 3 days before operation to detect the structural and functional parameters of atrium and ventricle.(1)Left atrial structural and functional parameters:Anteroposterior diameter of left atrium(LA-ap)?Left atrial volume index(LAVI)?Left atrial reservoir strain(LASr)?Left atrial strain in the pipeline phase(LAScd)?Left atrial pumping strain(LASct)and Left atrial electromechanical conduction time(LAEMT).(2)Right atrial structural and functional parameters:Transverse diameter of right atrium(RA-t)?Long diameter of right atrium(RA-l)?Right atrial area(RAA)?Right atrial reservoir phase strain(RASr)?Right atrial strain in the pipeline phase(RAScd)and Right atrial pumping strain(RASct).(3)Left ventricular structural and functional parameters:Left ventricular end diastolic diameter(LVEDD)?Left ventricular end systolic diameter(LVESD)?Left ventricular end diastolic volume(LVEDV)?Left ventricular end systolic volume(LVESV)?Left ventricular ejection fraction(LVEF)?Left ventricular global longitudinal strain(LVGLS)and Left ventricular diastolic function.(4)Right ventricular structural and functional parameters:Right ventricular basal diameter(RV-b)?Right ventricular end diastolic area(RVEDA)?Right ventricular end systolic area(RVESA)?Right ventricular fractional area change(RVFAC)?Global longitudinal strain of right ventricle(RVGLS)and Right ventricular diastolic function.3.CHA₂DS₂-VAS_Cscore?CAAP-AF score?BASE-AF₂ score:according to the assignment of each parameter in the scoring system,the score of each patient was calculated.4.Follow up after CBCA:Follow up included early recurrence follow-up and late recurrence follow-up.All patients received regular outpatient and telephone follow-up after operation.Dynamic electrocardiogram examination was performed at 1,3,6,12months after operation and every 6 months thereafter.If there were palpitations,chest tightness and other symptoms,ECG examination was required immediately.5.Research endpoint:Early recurrence of atrial fibrillation was defined as atrial flutter,atrial tachycardia or atrial fibrillation lasting at least 30 seconds recorded by ECG or Holter3 months after operation.This period is defined as the blank period.Late recurrence of AF was defined as atrial flutter,atrial tachycardia or atrial fibrillation lasting at least 30seconds recorded by ECG or Holter 3 to 12 months after surgery.6.Statistical methods:SPSS 25.0 software was used to analyze the related data.The measurement data were expressed by`x±s,and the count data were expressed by example and percentage.The measurement data of the two groups were compared by independent sample t-test,the measurement data of the three groups were compared by one-way ANOVA,and the count data of the two groups were compared by c² test.All hypothesis tests were bilateral test,P<0.05,the difference was statistically significant.Univariate logistic regression was used to analyze the relationship between each parameter and high CHA₂DS₂-VAS_C score(?2 points).Receiver operating characteristic(ROC)curve was used to test the diagnostic efficacy of each parameter for high CHA₂DS₂-VAS_C score.In addition,logistic regression analysis was used to determine the parameters that can predict the early recurrence of atrial fibrillation,and Cox regression analysis was used to determine the parameters that can predict the late recurrence of atrial fibrillation.The prediction ability of each model was evaluated by comparing the c² value obtained by likelihood ratio test.Kaplan Meier curve and log rank test were used to compare the differences of late recurrence between groups.The difference was statistically significant(P<0.05).Results:1.Evaluation of cardiac structure and function in patients with PAF by echocardiography(1)Atrial structure and function ChangesCompared with con group,the LA-ap and LAVI of PAF group were significantly increased(P<0.001),while the strain LASr,LAScd and LASct were significantly decreased(P<0.001),and the left atrial electrical mechanical conduction time(LAEMT)was prolonged(P<0.001),suggesting that PAF patients had lower left atrial reservoir function,channel function and pump function,and lower left atrial electrical conduction rate.Among them,only 38(26%)patients with PAF had LAVI higher than normal,suggesting that the left atrial size of most PAF patients was still within normal range.Compared with con group,RA-l and RAA in PAF group were significantly increased(P<0.05),while RASr and RAScd in strain were significantly decreased(P<0.001),suggesting that the function of right atrium reservoir and conduit was decreased.Among them,only 10(6.8%)PAF patients had RAA higher than normal,suggesting that most PAF patients had normal right atrial size.(2)Changes of ventricular structure and functionCompared with con group,LVEDD,LVESD,LVEDV and LVESV in PAF group were significantly increased(P<0.05),LVEF and LVGLS were significantly decreased(P<0.001),and the proportion of LVDD was increased(P<0.05).Among them,only 14(9.6%)patients had LVEDD higher than the normal value,indicating that the left ventricular size of most PAF patients was within the normal range;in PAF group,LVEF of all patients was within the normal range;in PAF group,124(84.9%)patients had LVGLS lower than the normal value,indicating that the left ventricular systolic function of most PAF patients was impaired;in PAF group,77(52.7%)patients had LVDD,indicating that left ventricular diastolic function is decreased in some PAF patients.Compared with con group,RV-b and RVESA in PAF group were significantly increased(P<0.05),RVFAC and RVGLS in PAF group were significantly decreased(P<0.05).However,RV-b and RVFAC of all patients in PAF group were in the normal range,indicating that the right ventricular size of PAF patients was still in the normal range;RVFAC of 37(25.3%)patients in PAF group was less than the normal value,indicating that a small number of PAF patients had impaired right ventricular systolic function.2.Relationship between echocardiographic parameters and high CHA₂DS₂-VAS_C score in patients with PAFA total of 146 patients with PAF were included,with an average age of 61.65±8.96years old and 76 males(52.1%).The average CHA₂DS₂-VAS_C score was 1.95±1.23.According to CHA₂DS₂-VAS_C score,the patients were divided into low CHA₂DS₂-VAS_Cscore group(<2 points,61 cases)and high CHA₂DS₂-VAS_C score group(?2 points,85cases).In the high CHA₂DS₂-VAS_C score group,LAEMT was significantly increased(P<0.05)and the proportion of LVDD was increased(P<0.05).LAEMT and LVDD were independent predictors of high CHA₂DS₂-VAS_C score.When LAEMT?216.5ms,the sensitivity and specificity of predicting high CHA₂DS₂-VAS_C score were 84.7%and 50.8%(AUC=0.72,P<0.001).The sensitivity and specificity of LVDD for predicting high CHA₂DS₂-VAS_C score were 70.1%and 55.9%(AUC=0.63,P<0.05).The sensitivity and specificity of combining LAEMT and LVDD to predict high CHA₂DS₂-VAS_C score were89.3%and 60.7%(AUC=0.81,P<0.001).The combination of LAEMT and LVDD improved the diagnostic efficiency of high CHA₂DS₂-VAS_C score(P<0.001).3.Value of echocardiographic parameters in predicting early recurrence of PAF after CBCAAmong 146 patients with PAF,42 patients(28.8%)had early recurrence after CBCA.They were divided into early recurrence group(42 cases,28.8%)and no early recurrence group(104 cases,71.2%).Among them,24 patients(57.1%)recovered sinus rhythm 3months after operation,and 18 patients(42.9%)developed late recurrence.CAAP-AF score could predict the early recurrence of PAF patients after CBCA(P<0.05),while CHA₂DS₂-VAS_C score could not predict the early recurrence of PAF patients after CBCA(P>0.05).LASr and LVGLS are independent predictors of early recurrence after CBCA in PAF patients,and can increase CAAP-AF score to predict early recurrence after CBCA in PAF patients.CAAP-AF score(c²=5.68)combined with echocardiographic parameters LASr and LVGLS significantly enhanced the ability to predict early recurrence of PAF patients after CBCA(c²=22.17,P<0.001).ROC curve results showed that when LASr?25.84%,the sensitivity and specificity of predicting early recurrence of PAF patients after CBCA were 81.8%and 73.5%(AUC=0.77,P<0.001);when LVGLS?-17.15%,the sensitivity and specificity of predicting early recurrence of PAF patients after CBCA were 90.2%and 46.1%(AUC=0.73,P<0.001).4.Value of echocardiographic parameters in predicting late recurrence of PAF after CBCAThe average follow-up time was 11.59±4.74(4-24)months.43(29.5%)PAF patients had late recurrence after CBCA.The average time of late recurrence was 7.26±2.87(4-12)months.According to whether there was late recurrence,they were divided into late recurrence group(43 cases,29.5%)and no late recurrence group(103 cases,70.5%).Among the 43 patients with late recurrence,18 patients(41.9%)had early recurrence.BASE-AF₂ score could predict the late recurrence of PAF patients after CBCA(P<0.05),while CHA₂DS₂-VAS_C score and CAAP-AF score could not predict the late recurrence of PAF patients after CBCA(P>0.05).LAEMT and LVGLS are independent predictors of late recurrence after CBCA,and can increase the value of BASE-AF₂ score to predict late recurrence after CBCA in PAF patients.After BASE-AF₂ score(c²=15.44)combined with LAEMT and LVGLS,the ability of predicting late recurrence of PAF patients after CBCA was significantly enhanced(c²=20.31,P<0.05).ROC curve results showed that when LAEMT?221.76 ms,the sensitivity and specificity of predicting late recurrence of PAF patients after CBCA were 60.5%and 70.0%(AUC=0.63,P<0.05);when LVGLS?-16.03%,the sensitivity and specificity of predicting late recurrence of PAF patients after CBCA were 88.4%and 37.0%(AUC=0.64,P<0.05).Kaplan Meier curve analysis showed that the incidence of late recurrence in patients with LAEMT?221.76ms was significantly higher than that in patients with LAEMT<221.76ms(P<0.05),and the incidence of late recurrence in patients with LVGLS?-16.03%was significantly higher than that in patients with LVGLS<-16.03%(P<0.05).Conclusion:1.In PAF patients the function of left atrium reservoir,pipeline and pump is impaired,left atrial electromechanical conduction time is prolonged;the function of right atrium reservoir and pipeline is impaired;left ventricular systolic and diastolic function is impaired;right ventricular systolic is impaired.2.LAEMT and LVDD were independent predictors of high CHA₂DS₂-VAS_Cscore(?2)in PAF patients,and the combination of LAEMT and LVDD significantly improved the diagnostic efficiency.3.LASr and LVGLS were independent predictors of early recurrence after CBCA in PAF patients,and could increase CAAP-AF score to predict early recurrence after CBCA in PAF patients.4.LAEMT and LVGLS were independent predictors of late recurrence after CBCA in PAF patients,and the value-added BASE-AF₂ score could predict late recurrence after CBCA in PAF patients.