Surgical Treatment of Atrial Fibrillation in Patients with Rheumatic Valve Disease

Surgical ablation of atrial fibrillation during mitral valve surgery: a systematic review and meta-analysis

Background

Atrial fibrillation (AF) is a common tachyarrhythmia, affecting approximately 33 million people worldwide, and is frequently associated with mitral valve disease. Surgical ablation during mitral valve surgery provides an opportune circumstance for arrhythmia correction. The results of recent randomized trial data are promising, demonstrating both safety and efficacy. The aim of this systematic review is to report the efficacy and morbidity of concomitant surgical ablation for AF during mitral valve surgery.

Methods

Five electronic databases were searched from inception to March 2023. All studies reporting the primary outcome, freedom from AF (FFAF), for patients with a history of AF undergoing concomitant mitral valve surgery were identified. Studies with patient cohorts less than 100 were excluded. Relevant data were extracted and a meta-analysis of proportions was conducted using a random-effects model. Survival data were pooled from original Kaplan-Meier curves and reconstructed, reporting aggregate FFAF and survival.

Results

Thirty-six studies with a total of 8,340 patients were included in the systematic review. All 36 papers reported postoperative FFAF with a pooled result of 76.9% [95% confidence interval (CI): 73.8-79.9%] at a weighted mean follow-up of 40.2 months, however this result was associated with significant heterogeneity (I2=89%). A total of 31 studies reported postoperative short-term mortality, with a pooled result of 1.68% (95% CI: 1.15-2.29%). Aggregate survival at 1 to 5 years was 93.7%, 92.5%, 91.3%, 89.4%, and 87%, respectively, and aggregate FFAF for 1 to 5 years was 90.2%, 83.5%, 79.5%, 76.4% and 73.2%, respectively.

Conclusions

Evaluation of the evidence suggests that concomitant ablation for AF during mitral valve surgery is both safe and efficacious. The results were associated with significant heterogeneity, reflective of variable institutional protocols, patient characteristics, and lesion sets. Randomized data with longer term follow-up would help validate these results.

Results of Surgical Ablation for Atrial Fibrillation in Patients with Rheumatic Heart Disease

Background

There is conflicting evidence regarding the success of the Maze procedure to restore sinus rhythm in patients with rheumatic heart disease. Hence, the aim of our study was to describe the results of surgical ablation for atrial fibrillation in patients with rheumatic heart disease undergoing cardiac surgery.

Methods

This is a retrospective study that included adult patients with rheumatic heart disease who underwent surgical ablation for atrial fibrillation. The ablation lesions were performed using monopolar radiofrequency ablation in all patients.

Results

Fifty-seven consecutive patients were included in the study. Cox Maze IV was performed in 44 patients (77%), while left-sided surgical ablation was performed in 10 patients (17%) and pulmonary vein isolation in 3 patients (5%). The percentage of patients who were in sinus rhythm on discharge, at 1-month, at 3-months, 6-months and 12-months follow up were 56%, 54%, 52%, 56% and 46% respectively. Complete heart block occurred in 21 patients (44%), but only 15 of them (26%) required permanent pacemaker insertion. Freedom from composite endpoint of death, stroke, and readmission for heart failure was 78% at one-year follow up.

Conclusion

Despite the suboptimal rates of sinus rhythm at the intermediate and long term follow up, surgical ablation of atrial fibrillation in patients with rheumatic heart disease should continue to be performed. Continuation of Class III antiarrhythmic medications and early intervention for recurrent atrial fibrillation is crucial to the success of this procedure and for maintenance of higher rates of sinus rhythm at intermediate and long-term follow up.

Bi-atrial versus left atrial ablation for patients with rheumatic mitral valve disease and non-paroxysmal atrial fibrillation (ABLATION): rationale, design and study protocol for a multicentre randomised controlled trial

INTRODUCTION

Atrial fibrillation (AF) is common in patients with rheumatic mitral valve disease (RMVD) and increase the risk of stroke and death. Bi-atrial or left atrial ablation remains controversial for treatment of AF during mitral valve surgery. The study aims to compare the efficacy and safety of bi-atrial ablation with those of left atrial ablation among patients with RMVD and persistent or long-standing persistent AF.

METHODS AND ANALYSIS

The ABLATION trial (Bi-atrial vs Left Atrial Ablation for Patients with RMVD and Non-paroxysmal AF) is a prospective, multicentre, randomised controlled study. The trial will randomly assign 320 patients with RMVD and persistent or long-standing persistent AF to bi-atrial ablation procedure or left atrial ablation procedure in a 1:1 randomisation. The primary end point is freedom from documented AF, atrial flutter or atrial tachycardia of >30 s at 12 months after surgery off antiarrhythmic drugs. Key secondary end point is the probability of freedom from permanent pacemaker implantation at 12 months after surgery. Secondary outcomes include the probability of freedom from any recurrence of atrial tachyarrhythmias with antiarrhythmic drugs, AF burden, incidence of adverse events and cardiac function documented by echocardiography at 12 months after operation.

ETHICS AND DISSEMINATION

The central ethics committee at Fuwai Hospital approved the ABLATION trial. The results of this study will be disseminated through publications in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05021601.

Long-term outcomes of radiofrequency catheter ablation for atrial fibrillation in rheumatic heart disease patients with mild mitral stenosis

PURPOSE

To assess efficacy of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in rheumatic heart disease (RHD) patients with mild mitral stenosis (MS).

METHODS

This retrospective cohort study included 62 consecutive RHD patients with mild MS and AF and 124 AF patients without RHD with matched age, gender, AF types as control. Procedure endpoints were defined as circumferential pulmonary vein ablation (CPVA) for paroxysmal AF, CPVA plus bidirectional block of lines, and disappearance of complex fractionated atrial electrograms for non-paroxysmal patients in both groups.

RESULTS

Cumulative success rate during the total follow-up (RHD, 23-140 months; control, 24-140 months) was lower in RHD group than control (32.3 vs. 56.5%, log-rank P = 0.006). In RHD patients, the success rate was higher in paroxysmal AF patients than non-paroxysmal AF patients during the mid-term follow-up (55.0 vs. 26.2%, log-rank P = 0.041), and was similar between the two AF types during the total follow-up (45.0 vs. 26.2%, log-rank P = 0.130). Patients without mitral regurgitation (MR) or with mild MR had a higher success rate than patients with moderate MR during the total follow-up in both groups (45.0 vs. 9.1%, log-rank P = 0.014 in RHD group; 64.5 vs. 43.8%, log-rank P = 0.001 in control group).

CONCLUSIONS

The long-term outcome of RFCA for AF in RHD patients with mild MS was mediocre and worse than that for AF patients without RHD. The severity of MR was associated with RFCA outcome in both groups. In RHD patients with mild MS, a better prognosis of paroxysmal AF than non-paroxysmal AF was observed initially but turned similar over time.

Which Method to Use for Surgical Ablation of Atrial Fibrillation Performed Concomitantly with Mitral Valve Surgery: Radiofrequency Ablation versus Cryoablation

Objective

The effects of energy source on the maintenance of sinus rhythm and the contribution of demographic characteristics to the case selection in patients submitted to ablation performed concurrently with mitral valve surgery were analyzed.

Methods

Cryothermal (n=42; 43.8%) and radiofrequency (n=54; 56.3%) energy were employed in 96 patients submitted to mitral valve replacement and Cox maze IV procedure. Patients were called for control visits between 15 days and 12 months after discharge. The causal relationship between recurrence of atrial fibrillation and factors such as left atrial diameter, C-reactive protein, hypertension, left ventricular ejection fraction, chronic obstructive pulmonary disease, and body mass index was determined.

Results

Maintenance rates of the sinus rhythm with radiofrequency and cryoablation were 97.6% and 96.3%, respectively, in the first postoperative month, whereas at the 12^th postoperative month were 88.1% and 83.3%. No significant difference was found between groups in relation to the energy source. Sensitivity and specificity for left atrial diameter with a cut-off value of 50.5 mm were 85.7% and 70.7%, respectively. Sensitivity and specificity for C-reactive protein with a cut-off value of 12 mg/dL on the 15^th postoperative day were 83.3% and 88.9%, respectively. The effect of body mass index on atrial fibrillation recurrence was 3.2 times. Sensitivity and specificity for left ventricular ejection fraction 37% cut-off value were 96.3% and 11.4%, respectively. Atrial fibrillation in hypertensive cases was 5.3 times more. In patients with chronic obstructive pulmonary disease, recurrence of atrial fibrillation was 40%. The causal relation between recurrence of atrial fibrillation and the studied factors was established.

Conclusion

Demographic characteristics have a significant impact on ablation efficiency, while the type of energy source does not.

Characteristics, Mechanism and Long-Term Ablation Outcome of Atrial Tachycardias After Mitral Valvular Surgery and Concomitant Cox-MAZE IV Procedure

The incidence of atrial tachycardia (AT) after rheumatic mitral valvular (RMV) surgery has been well described. However, there have been few reports on the characteristics, mechanism, and long-term ablation outcome of ATs after RMV surgery and concomitant Cox-MAZE IV procedure.The present study reviewed consecutive patients who underwent AT ablation between May 2008 and July 2013. All patients were refractory to antiarrhythmic drugs (AADs) and had a history of RMV surgery and Cox-MAZE IV procedure. A total of 34 patients underwent AT ablation after RMV surgery and concomitant Cox-MAZE IV procedure, and presented 57 mappable and 2 unmappable ATs. The 57 mappable ATs included 14 focal-ATs and 43 reentry-ATs. Ten of the 14 focal-like ATs were located at the pulmonary vein (PV) antrum and border of a box lesion. Of the 43 reentry-ATs, 16 were marco-reentrant around the mitral annulus (MA) and 16 around the tricuspid annulus. There were 41 atypical ATs (non-cavotricuspid isthmus related) including 16 ATs related to the box lesion and 21 ATs related to other Cox-MAZE IV lesions. The AT were successfully terminated in 33 (97.1%) patients. After mean follow-up of 46.9 ± 15.7 months, 25 (73.5%) patients maintained sinus rhythm without AADs after a single procedure and 28 (82.4%) patients after repeated procedures.The recurrent ATs after RMV surgery and concomitant Cox-MAZE IV were mainly reentry mechanism, and largely related to LA. An incomplete lesion or re-conductive gaps in a prior lesion might be the predominant mechanisms for these ATs. Catheter-based mapping and ablation of these ATs seems to be effective and safe during a long-term follow-up.