Bipolar radiofrequency ablation is useful for treating atrial fibrillation combined with heart valve diseases

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.

Blood microbiota diversity determines response of advanced colorectal cancer to chemotherapy combined with adoptive T cell immunotherapy

Human microbiota influence the response of malignancies to treatment with immune checkpoint blockade; however, their impact on other forms of immunotherapy is poorly understood. This study explored the effect of blood microbiota on clinical efficacy, represented by progression-free survival (PFS) and overall survival (OS), of combined chemotherapy and adoptive cellular therapy (ACT) in advanced colon cancer patients. Plasma was collected from colorectal cancer patients (CRC) treated with either chemotherapy alone (oxaliplatin and capecitabine) (XELOX CT alone group, n = 19), or ACT with a mixed dendritic cell/cytokine-induced killer cell product (DC-CIK) + XELOX (ICT group, n = 20). Circulating microbiota analysis was performed by PCR amplification and next-generation sequencing of variable regions V3~V4 of bacterial 16S rRNA genes. The association of the blood microbial diversity with clinical response to the therapy as measured by RECIST1.1 and OS was evaluated. The baseline Chao index of blood microbial diversity predicted prolonged PFS and OS of DC/CIK immunotherapy. More diverse blood microbiota that included Bifidobacterium, Lactobacillus, and Enterococcus were identified among responders to DC/CIK compared with non-responders. The plasma bacterial DNA copy number is inversely correlated with the CD3-/CD16+/CD56+ NK cells in circulation and decreased following DC-CIK; however, the Chao index of plasma microbiota significantly increased after administration of the DC-CIK product and this subsequent change was correlated with the number of CD3-/CD16+/CD56+ and CD8+/CD28+ cells infused. The diversity of the blood microbiome is a promising predictive marker for clinical responses to chemotherapy combined with DC-CIK. Cellular immunotherapy can affect the plasma microbiota's diversity in a manner favorable to clinical responses.

Surgical Endoepicardial Linear Ablation for Ventricular Tachycardia With Postinfarction Left Ventricular Aneurysm

This retrospective study evaluated the feasibility of surgical endoepicardial linear ablation for ventricular tachycardia in patients with postinfarction left ventricular aneurysm. Sixty-four patients with multivessel coronary artery disease and left ventricular aneurysm but no mural thrombosis of the aneurysm or valve disease were treated at our institution from March 2012 through July 2015. All underwent off-pump coronary artery bypass grafting and left ventricular aneurysm repair by linear plication. Twenty-three patients (35.9%) had ventricular tachycardia and underwent surgical endoepicardial linear ablation on the beating heart guided by epicardial substrate mapping with the Carto 3 system. The remaining 41 patients (64.1%) composed the no-ablation group. The effectiveness of surgical linear ablation in the ablation group was evaluated. Safety and clinical outcomes were evaluated and compared between the groups. The ventricular tachycardia recurrence rate in the ablation group was 17.4% in the immediate postoperative period and 23.8% at last follow-up (39 ± 21 mo). Early (<30-d) mortality rates were 8.7% in the ablation group and 4.9% in the no-ablation group (P=0.41); the respective late mortality rates were 19.1% and 18% (P=0.70). Multivariate Cox regression analysis indicated that preoperatively poor left ventricular function was an independent risk factor for early and late death in both groups. The groups were similar in terms of the need for postoperative mechanical circulatory support, intensive care unit stay, and cumulative survival rate. We conclude that, for carefully selected candidates, surgical endoepicardial linear ablation combined with off-pump coronary artery bypass grafting and left ventricular aneurysm linear plication is a feasible treatment for ventricular tachycardia with postinfarction left ventricular aneurysm.

Long-term results of monopolar versus bipolar radiofrequency ablation procedure for atrial fibrillation

Background

In this study, we aimed to evaluate the long-term outcomes of monopolar or bipolar radiofrequency ablation concomitant to mitral valve surgery in patients with atrial fibrillation.

Methods

We retrospectively evaluated a total of 167 patients (67 males, 100 females; mean age 56.8±6.9 years; range, 48 to 65 years) with atrial fibrillation who underwent monopolar or bipolar radiofrequency ablation concomitant to mitral valve surgery between September 2001 and January 2015. The patients were divided into two groups according to the procedure applied as those undergoing monopolar ablation (group 1, n=68) and those undergoing bipolar ablation (group 2, n=99). All patients were followed by electrocardiogram and 24-h Holter monitoring. Echocardiography was performed before discharge, at three and 12 months postoperatively, and annually thereafter. Left atrial volume index, left atrial diameter, and left ventricular ejection fraction were recorded.

Results

There was no significant correlation between the procedure applied and hypertension, hyperlipidemia, diabetes mellitus, chronic obstructive pulmonary disease, history of the cerebrovascular events (p>0.05). The mean preoperative left atrial diameter decreased from 5.3±0.5 cm to 4.9±0.5 cm postoperatively in all patients (p=0.0001). The mean preoperative left atrial volume index decreased from 53.8±0.4 mL/m2 t o 43.7±6.2 m L/m2 i n t he postoperative period (p=0.0001). During follow-up, 61.8% (n=42) of the patients in group 1 and 62.6% (n=62) of the patients in group 2 remained in sinus rhythm. One patient (1.5%) in group 1 and two patients (2.0%) in group 2 developed early postoperative cerebrovascular accident.

Conclusion

Monopolar and bipolar ablation methods are safe and effective methods to ensure long-term sinus rhythm. Both procedures do not increase the morbidity risk with very low thromboembolic complication rates.

Precise Drug Sequential Therapy Can Improve the Cardioversion Rate of Atrial Fibrillation with Valvular Disease after Radiofrequency Ablation

OBJECTIVE

Based on pathogenesis of atrial fibrillation (AF), investigate the effects of precision drugs continuous therapy on AF cardioversion rate after radiofrequency catheter ablation.

METHODS

We included 1334 patients who underwent mitral valve replacement with bipolar radiofrequency ablation due to mitral valve disease with AF during June 2011 to July 2017. The data of clinical and related laboratory examinations at discharge and follow-up were recorded. All patients were treated with or without angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II-receptor blocker (ARB) drugs according to their conditions and doctor's willingness. The heart rhythm was evaluated after treatment and follow-up of 6 months.

RESULTS

All 1162 cases were followed up, including 825 cases in mitral stenosis (MS) group, 337 cases in mitral regurgitation (MR) group. In MS group, left atrial diameter(LAD) and left ventricular diameter(LVD) of the patients taking ACEI and ARB were significantly lower (P < 0.05), and they can increase AF cardioversion rate from 79.1% of the control group to 83.7% and 82.8%, respectively (P = 0.03 and 0.04). In MR group, the patients with ACEI compared with control group, there were no significant differences in LAD, LVD, right atrial diameter (RAD), right ventricular diameter (RVD), left ventricular ejection fraction(LVEF), and left ventricular fractional shortening(LVFS) (P > 0.05); but ARB group, LAD, LVD decreased significantly (P < 0.05). And ACEI can increase AF cardioversion rate from 76.1% in the control group to 77.2% (P = 0.62), ARB to 81.6% (P = 0.02).

CONCLUSION

It does improve AF cardioversion rate after radiofrequency catheter ablation that the precise anti-structural remodeling drugs continuous therapy was adopted based on the pathogenesis of AF.

The Factors Affecting Rhythm Control for Cryoablation of Atrial Fibrillation in Mitral Valve Surgery

OBJECTIVE

To evaluate the factors impacting on the conversion to sinus rhythm and on the postoperative rhythm findings in the six-month follow-up period of a mitral valve surgery combined with cryoablation Cox-Maze III procedure, in patients with atrial fibrillation.

METHODS

In this study, we evaluated 80 patients who underwent structural valve disease surgery in combination with cryoablation. Indications for the surgical procedures were determined in the patients according to the presence of rheumatic or non-rheumatic structural disorders in the mitral valve as evaluated by echocardiography. Cox-Maze III procedure and left atrial appendix closure were applied.

RESULTS

The results of receiver operating characteristics analysis indicated that the rate of conversion to the sinus rhythm was significantly higher in patients with left atrial diameters ≥ 45.5 mm and with ejection fraction (EF) ≥ 48.5%. However, the statistical differences disappeared in the sixth month. Thromboembolic (TE) events were seen only in three patients in the early period and no more TE events occurred in the six-month follow-up period.

CONCLUSION

The EF and the preoperative left atrial diameter were determined to be the factors impacting on the conversion to sinus rhythm in patients who underwent mitral valve surgery in combination with cryoablation. Mitral valve surgery in combination with ablation for atrial fibrillation does not affect mortality and morbidity in the experienced health centers; however, it remains controversial whether it will provide additional health benefits to the patients compared to those who underwent only mitral valve surgery.

Safety and efficacy of biatrial vs left atrial surgical ablation during concomitant cardiac surgery: A meta-analysis of clinical studies with a focus on the causes of pacemaker implantation

INTRODUCTION

The latest STS guidelines recommend concomitant atrial fibrillation (AF) ablation not only during mitral surgery (Class IA) but also during other-than-mitral cardiac surgery procedures (Class IB) in patients with preoperative AF. Conventional Cox-Maze III/IV procedures are performed on both atria (BA), but several studies reported excellent results with left atrial only (LA) ablations: the scope of this study is to compare the safety and efficacy of BA vs LA approach.

METHODS AND RESULTS

Pubmed, Scopus, and WOS were searched from inception to November 2018: 28 studies including 7065 patients and comparing the performance of BA vs LA approaches were identified: of these, 16 (57.1%) enrolled exclusively patients with non-paroxysmal AF forms, 10 (35.7%) focused on mitral surgery as main procedure, and 16 (57.1%) regarded patients undergone Cox-Maze with radiofrequency. The 6- and 12-months prevalence of sinus rhythm were higher in the BA group (OR, 1.37, CI, 1.09-1.73, P = .008 and OR, 1.37, CI, 0.99-1.88, P = .05 respectively). Permanent pacemaker (PPM) implantation (OR, 1.85, CI, 1.38-2.49, P < .0001) and reopening for bleeding (OR, 1.70, CI, 1.05-2.75, P = .03) were higher in the BA group. Among patients undergone PPM implantation, BA group had a significantly higher risk of sinoatrial node dysfunction (OR, 3.01, CI, 1.49-6.07, P = .002).

CONCLUSIONS

Concomitant BA ablation appears superior to LA ablation in terms of efficacy but is associated with a higher risk of bleeding and of PPM implantation, more frequently due to sinoatrial node dysfunction. LA approach should be preferable in patients with a higher risk of bleeding or with perioperative risk factors for PPM implantation.

Long-Term Results of Surgical Atrial Fibrillation Radiofrequency Ablation: Comparison of Two Methods

BACKGROUND

This retrospective study aimed to evaluate the long-term results of two kinds of surgical atrial fibrillation radiofrequency ablations in concomitant cardiac operations.

METHODS

We enrolled 129 patients from January 2006 to December 2015 and performed cardiac operations concomitantly with surgical atrial fibrillation. The patients were divided into a biatrial MAZE group (94 patients) and a left atrial MAZE group (35 patients). A preoperative baseline was compared with intraoperative and postoperative data. Similarly, complications and follow-up results were compared. A matching process based on propensity-score was performed to equalise the potential prognostic factors in both groups and to formulate a balanced 2:1 matched cohort study.

RESULTS

There were four deaths (4.3%) in the biatrial MAZE group and one death in left atrial MAZE group due to multiple organ failures followed by low cardiac output. No permanent pacemaker implantations were used in either group. The sinus rhythm maintenance rates at the 6-month, 1-year, 6-year and 8-year follow-ups between the biatrial MAZE group and the left atrial MAZE group were not significantly different (84.7%, 83.3%, 67.3%, and 58.8% vs. 84.9%, 77.4%, 61.1%, and 50%, p>0.05). Similarly, between the propensity-score matched groups, there were no significant differences.

CONCLUSION

The left atrial MAZE ablation for the patients with mitral valve diseases who needed open cardiac operation was safe and effective when compared with the biatrial MAZE ablation group.

Surgical Treatment of Atrial Fibrillation in Patients with Rheumatic Valve Disease

OBJECTIVE:

To assess heart rhythm and predictive factors associated with sinus rhythm after one year in patients with rheumatic valve disease undergoing concomitant surgical treatment of atrial fibrillation. Operative mortality, survival and occurrence of stroke after one year were also evaluated.

METHODS:

Retrospective longitudinal observational study of 103 patients undergoing rheumatic mitral valve surgery and ablation of atrial fibrillation using uni- or bipolar radiofrequency between January 2013 and December 2014. Age, gender, functional class (NYHA), type of atrial fibrillation, EuroSCORE, duration of atrial fibrillation, stroke, left atrial size, left ventricular ejection fraction, cardiopulmonary bypass time, myocardial ischemia time and type of radiofrequency were investigated.

RESULTS:

After one year, 66.3% of patients were in sinus rhythm. Sinus rhythm at hospital discharge, lower left atrial size in the preoperative period and bipolar radiofrequency were associated with a greater chance of sinus rhythm after one year. Operative mortality was 7.7%. Survival rate after one year was 92.3% and occurrence of stroke was 1%.

CONCLUSION:

Atrial fibrillation ablation surgery with surgical approach of rheumatic mitral valve resulted in 63.1% patients in sinus rhythm after one year. Discharge from hospital in sinus rhythm was a predictor of maintenance of this rhythm. Increased left atrium and use of unipolar radiofrequency were associated with lower chance of sinus rhythm. Operative mortality rate of 7.7% and survival and stroke-free survival contribute to excellent care results for this approach.

Analysis of Bipolar Radiofrequency Ablation in Treatment of Atrial Fibrillation Associated with Rheumatic Heart Disease

Background

Among patients with rheumatic heart disease (RHD), 45% to 60% present with atrial fibrillation (AF), which is associated with increased rates of thromboembolism, heart failure, and even death. The bipolar radiofrequency ablation (BRFA) combining with mitral valve procedure has been adopted in patients of AF associated with RHD, but evaluations about its effectiveness are still limited.

Methods

A total of 87 patients with RHD and long persistent AF who had accepted mitral valve replacement concomitant with BRFA were studied. Clinical data were collected to analyze the midterm results of BRFA and evaluate its efficiency. Univariate and multivariate analyses were used to identify the independent factors associated with late AF recurrence.

Results

Sixty-six (75.9%) patients maintained sinus rhythm after a mean follow-up of 13.4 ± 5.2 months. Late AF recurrence had been detected in 21 (24.1%) patients, 11 (12.6%) patients were confirmed to be AF, 8 (9.2%) patients were atrial flutter and 2 (2.3%) patients were junctional rhythm. In Multivariate logistic regression analysis, body mass index (BMI) (OR = 1.756, 95% CI = 1.289–2.391, p = 0.000) and early AF recurrence (OR = 5.479, 95% CI = 1.189–25.254, p = 0.029) were independent predictors of late AF recurrence. In addition, left ventricular ejection fraction (LVEF) and New York Heart Association class showed a greater improvement in patients who maintained sinus rhythm than those who experienced late AF recurrence.

Conclusion

BRFA is an effective technique for the treatment of long persistent AF associated with RHD during mitral valve replacement. The BMI and early AF recurrence are independent predictors for late AF recurrence. Patients with long-term restoration of sinus rhythm experienced a greater improvement of left ventricular function after BRFA.