| Atrial fibrillation(AF)is the most common clinical arrhythmia.The incidence of AF in the general population is 0.5-1.3%,and the incidence increases gradually with age.Patients with atrial fibrillation are at potential thromboembolic risk.Among them,Stroke is the most common and harmful complication of atrial fibrillation.Therefore,stroke prevention is the key part of the management of patients with NVAF.The vitamin K oral anticoagulant warfarin is effective in reducing the risk of stroke by 60%.Novel oral anticoagulants(NOAC)have been shown to further reduce stroke,intracranial hemorrhage,and mortality compared to warfarin therapy.However,in the clinical work,poor patient compliance and frequent monitoring of coagulation severely limit its use due to the narrow therapeutic window of warfarin.The efficacy of new anticoagulants is no less than warfarin,but they are expensive and increase the risk of bleeding,and lack stable effective antagonists,so their application is often not ideal.With the continuous development of catheter ablation(CA)techniques in recent years,catheter ablation is increasingly used for drug-resistant atrial fibrillation.Several randomized studies have shown that the rhythm control of catheter ablation is significantly better than that of antiarrhythmic drug therapy.The level of recommendation for catheter ablation in the treatment of atrial fibrillation continues to increase in European and US guidelines.However,long-term effects of this therapy remain unpredictable because arrhythmia recurs at high rates over time,especially in patients with persistent AF,who need ongoing stroke prevention treatment.These unmet clinical needs have led to the emergence of new treatments and percutaneous left atrial appendage closure(LAAC)has emerged as a non-pharmacologic alternative for stroke prophylaxis in NVAF patients.It can be performed as a stand-alone procedure or in combination with CA,which enables sinus rhythm(SR)control and stroke prevention in one single process.Recent studies have shown that the combination of LAAC with CA is safe and feasible for AF patients.With the worldwide recognition of LAAC and its rapid development in the prevention of cardioembolic stroke,and there are still many issues worthy of further exploration.The left atrial appendage(LAA)was previously considered a dormant embryological remnant.However,emerging evidence indicates that it is a functional organ.Firstly,some studies have confirmed that left atrial appendage may be a potential inducing target of atrial fibrillation outside the pulmonary veins,and that the electrical isolation of the LAA may increase the success rate of atrial fibrillation ablation.It is not clear whether additional LAAC would affect the success rate of ablation on the basis of catheter ablation.Secondly,the LAA has a secretory function,which can secrete atrial natriuretic peptide(ANP)and brain natriuretic peptide(BNP)to regulate water and sodium metabolism.In addition to this,the LAA plays an important role in cardiac hemodynamics through its contractile properties,which are in fact greater and more consequential than those of the LA,contributing to LA compliance and function modulation.Catheter ablation itself can also have an influence on LA function by restoring and maintaining sinus rhythm and iatrogenic myocardial damage.We consequently hypothesized that the combined therapy might play an important role in cardiac hemodynamics and affect cardiac endocrine and mechanical functions.Based on the above-mentioned problems,we designed this study.Persistent AF,even long-standing persistent AF,is difficult to treat inasmuch as arrhythmia recurs at significant rates after catheter ablation therapy.Hence,this study focuses on patients with persistent AF at high risk of stroke and bleeding.The research is divided into three parts.In the first part,the patients with persistent atrial fibrillation treated with combined therapy and simple catheter ablation were followed up for 1 year,and compared the difference of recurrence rate of atrial fibrillation between the two procedures modalities to determine whether LAAC affects the recurrence rate of AF ablation,which further examines optimized therapeutic strategies of persistent atrial fibrillation.The second part discusses the effect of combined therapy on the secretion of BNP.Considering the endocrine function of LAA,We further explore whether additional LAAC on the basis of catheter ablation would affect BNP secretion and then affect cardiac endocrine function.The third part discusses the impact of combined therapy operation on left atrial structure and function.By comparing the echocardiographic changes between the combined therapy and simple catheter ablation groups,the impact of the additional LAAC procedure on LA function after CA treatment was investigated.This may provide more insights into the selection of the best treatment strategy for LAAC management.Part One Effect of left atrial appendage closure in combination with catheter ablation on left atrial function for persistent atrial fibrillationObjective:Atrial fibrillation is the most common arrhythmia in clinical practice and increases the risk of ischemic stroke.Stroke prevention is a core part of the management of patients with non-valvular atrial fibrillation.Percutaneous LAA closure has emerged as an alternative treatment strategy for stroke prevention in patients with non-valvular atrial fibrillation who can not tolerate OAC.The LA appendage was previously considered a dormant embryological remnant.However,emerging evidence indicates that it is a functional organ that plays an important role in cardiac hemodynamics through its contractile properties,which are in fact greater and more consequential than those of the LA,contributing to LA compliance and function modulation.We aimed to investigate the changes of LA function in persistent AF patients undergoing concomitant LAAC and CA.Given that the systolic and characteristics of the left atrial appendage may affect the function of the left atrial,we compared the echocardiographic changes between the combined therapy and simple ablation groups and further investigated the impact of the additional LAAC procedure on LA function after CA treatment.This may provide more insights into the selection of the best treatment strategy for LAAC management.Methods: In this study,the study population comprised 65 patients who underwent combined AF ablation and Watchman LAAC(combined therapy group)in our center,and 65 participants of the AF simple catheter ablation group who were matched based on sex,age,CHA2DS2-VASc score and HAS-BLED score using propensity score matching.Considering that different heart rhythms(sinus rhythm or atrial fibrillation)may affect the echo parameters determination,we excluded patients with preoperative sinus rhythm and postoperative atrial fibrillation recurrence.During the 1-year follow-up period,two-dimensional echocardiography and speckle tracking echocardiography were performed to assess LA reservoir,conduit,and contractile function.Results: Pulmonary vein isolation was successfully performed in both groups,and all patients were in sinus rhythm postoperatively.In the combined therapy group,the watchman LAAC was successfully implanted.There were no statistically differences in age,gender,hypertension,diabetes,coronary heart disease,cerebrovascular disease,heart failure,the proportion of persistent atrial fibrillation and long-term persistent atrial fibrillation,CHA2DS2-VASC score and HASBLED score between the two groups.Out of130 patients,45 were excluded due to sinus rhythm at baseline and AF or atrial flutter,leaving 85 patients(41 in the combined therapy group and 44 in the catheter ablation group)for the analysis of ultrasound data.The combined therapy was associated with a significant improvement in the LA reservoir function with increased expansion index and strain indices,including strain and strain rate(SR)during ventricular systole.Conduit function with SR during early ventricular diastole was also improved,as was contractile function with active atrial emptying fraction and SR during atrial systole.Similarly,LA reservoir and contractile function indices all improved continuously during follow-up after catheter ablation alone.At 3 months follow-up LA reservoir and conduit function with strain indices had a tendency to improve only in the simple procedure group.At 1-year follow-up there was no significant difference in either LA volumes or strain indices between the two groups.Conclusions: Both the combined therapy group and the simple ablation group demonstrated significant improvement in left atrial function.Based upon the fact that LA function was improved in both groups it might be concluded that most of the effects appeared to result from ablation,not LAAC;furthermore the additional LAAC procedure did not affect the improvement of LA function after catheter ablation.Part Two Effect of left atrial appendage closure in combination with catheter ablation on brain natriuretic peptide levels for persistent atrial fibrillation.Objective: Atrial fibrillation is the most common and concerned arrhythmia in clinical practice.Catheter ablation is currently recommended as the preferred treatment for AF compared to drug therapy.However,it has not been used as an effective means of stroke prevention.Percutaneous left atrial appendage closure fills this gap and has become an alternative treatment strategy for stroke prevention in patients with non-valvular atrial fibrillation.Left atrial appendage closure combined with catheter ablation is an effective method for control and stroke prevention.The LAA was previously considered a dormant embryological remnant.Emerging evidence has highlighted the importance of LAA in neurohormonal regulation and cardiac hemodynamics.Owing to its hormone-producing,the LAA is essential for fluid and electrolyte balance in the human body.The effect of combined therapy on BNP secretion is currently unclear.The purpose of this study was to investigate the effect of the combined therapy on BNP secretion.Considering the endocrine function of left atrial appendage,we further explored whether additional left atrial appendage closure on the basis of catheter ablation would affect the secretion of BNP and thus affect the endocrine function of the heart.Methods: In this study,the study population comprised 65 patients who underwent combined AF ablation and Watchman LAAC(combined therapy group)in our center,and 65 participants of the AF simple catheter ablation group who were matched based on sex,age,CHA2DS2-VASc score and HAS-BLED score using propensity score matching.Patients were examined for brain natriuretic peptide(BNP)levels to represent endocrine cardiac function.During the 1-year follow-up period,Venous blood samples were obtained for BNP assessment before the operation,1 day,2 days,3 days,3months,and 1 year after the operation.Considering that different heart rhythms(sinus rhythm or atrial fibrillation)may affect the level of BNP determination,we excluded patients with preoperative sinus rhythm and postoperative atrial fibrillation recurrence.Afterwards,monitor the change trend of BNP levels in the two groups,and compare the differences in BNP levels between the two groups.Results: Pulmonary vein isolation was successfully performed in both groups,and all patients were in sinus rhythm postoperatively.In the combined therapy group,the watchman LAAC was successfully implanted.There were no statistically differences in age,gender,hypertension,diabetes,coronary heart disease,cerebrovascular disease,heart failure,the proportion of persistent atrial fibrillation and long-term persistent atrial fibrillation,CHA2DS2-VASC score and HASBLED score between the two groups.Out of130 patients,45 were excluded due to sinus rhythm at baseline and AF or atrial flutter,leaving 85 patients(41 in the combined therapy group and 44 in the catheter ablation group)for the analysis of BNP data.In patients treated with CA and LAAC,the BNP levels acutely decreased with the restoration of SR,rose until day 3 post-operation,and then trended downwards at 3 and12-month post-operation.The same trend was observed for the BNP levels in the simple CA group.There was no significant difference concerning BNP levels between the two groups.Conclusion: The combined procedure of LAAC and CA significantly improved the endocrine function of the heart.Compared to simple CA,based on CA with LAAC intervention does not significantly change LA endocrine function.Part Three Effect of left atrial appendage closure combined with cath- eter ablation on the success rate of ablation in patients with persistent atrial fibrillationObjective: Percutaneous left atrial appendage closure combined with catheter ablation is an effective method for rhythm control and stroke prevention.Studies have shown that left atrial appendage may be a potential target for atrial fibrillation outside the pulmonary veins,and that the electrical isolation of left atrial appendage may increase the success rate of atrial fibrillation ablation.It is not clear whether additional left atrial appendage closure will affect the success rate of atrial fibrillation ablation on the basis of catheter ablation.The purpose of this study was to investigate the effect of left atrial appendage closure on the recurrence rate of atrial fibrillation on the basis of catheter ablation of persistent atrial fibrillation,and to provide evidence for the optimal treatment of persistent atrial fibrillation.Methods: In this study,the study population comprised 65 patients who underwent combined AF ablation and Watchman LAAC(combined therapy group)in our center,and 65 participants of the AF simple catheter ablation group who were matched based on sex,age,CHA2DS2-VASc score and HAS-BLED score using propensity score matching.During the 1-year follow-up period,post procedural 24-h monitor recordings were obtained 1,3,6,12 months after surgery to evaluate the presence of atrial arrhythmias.AF or recurrent atrial flutter was defined as any documented AF or atrial flutter lasting more than 30 s after the blanking period without antiarrhythmic drug therapy.At the same time,the incidence of perioperative complications,stroke and bleeding events during the follow-up period were compared between the two groups.All combined therapy patients underwent transesophageal echocardiography at the three-month follow-up to document device-related thrombus and peri-device leakage.Results: Pulmonary vein isolation was successfully performed in both groups,and all patients were in sinus rhythm postoperatively.In the combined therapy group,the watchman LAAC was successfully implanted.There were no statistically differences in age,gender,hypertension,diabetes,coronary heart disease,cerebrovascular disease,heart failure,the proportion of persistent atrial fibrillation and long-term persistent atrial fibrillation,CHA2DS2-VASC score and HASBLED score between the two groups.There was no significant difference in the incidence of perioperative complications between the combined therapy and catheter ablation groups(5% vs 2%,p=0.619).The incidence of stroke and the incidence of bleeding during postoperative follow-up were not significantly different.Device-related thrombus was observed in one patient,and no peri-device leaks >5mm were detected at the 3-month TEE follow-up.During 12-month of follow-up,18patients(28%)in combined therapy group and 16 patients(25%)in simple ablation group had recurrent AF(P=0.984 log-rank test).Conclusion: Combined therapy is safe and effective in the treatment of atrial fibrillation.On the basis of catheter ablation,additional left atrial appendage closure had no effect on the success rate of atrial fibrillation ablation. |
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