Surgical Atrial Fibrillation Ablation With and Without Left Atrium Reduction for Patients Scheduled for Mitral Valve Surgery: A Prospective Randomised Study

Left Atrium Volume Reduction Procedure Concomitant With Cox-Maze Ablation in Patients Undergoing Mitral Valve Surgery: A Meta-Analysis of Clinical and Rhythm Outcomes

BACKGROUND

The management of an enlarged left atrium (LA) in mitral valve (MV) disease with atrial fibrillation (AF) is still being debated. It has been postulated that a reduction in LA size may improve patient outcomes. This meta-analysis aimed to assess rhythm and clinical outcomes of combined surgical AF treatment with or without LA volume reduction (LAVR) in patients undergoing MV surgery.

METHODS

A systematic review was performed and all available literature to May 2022 was included. The primary endpoint was analysis of early and late mortality and rhythm outcomes. Secondary outcomes included early and late cerebrovascular accident (CVA) and permanent pacemaker implantation.

RESULTS

The search strategy yielded 2,808 potentially relevant articles, and 19 papers were eventually included. The pooled estimated rate of 30-day mortality was 3.76% (95% CI 2.52-5.56). The incidence rate of late mortality and late cardiac-related mortality was 1.75%/year (95% CI 0.63-4.84) and 1.04%/year (95% CI 0.31-3.53), respectively. At subgroup analysis when comparing the surgical procedure with and without AF ablation, the ablation subgroup showed a significantly lower rate of postoperative CVA (p<0.0001) and higher restoration to sinus rhythm at discharge (p=0.0124), with only a trend of lower AF recurrence at 1 year (p=0.0608). At univariable meta-regression, reintervention was significantly associated with higher late mortality (p=0.0033).

CONCLUSION

In enlarged LA undergoing MV surgery, LAVR combined with AF ablation showed a trend of improved rhythm outcomes when compared with AF ablation without LAVR. Each LAVR technique has its advantages and disadvantages, which must be managed accordingly.

Decreased diastolic hydraulic forces incrementally associate with survival beyond conventional measures of diastolic dysfunction

Decreased hydraulic forces during diastole contribute to reduced left ventricular (LV) filling and heart failure with preserved ejection fraction. However, their association with diastolic function and patient outcomes are unknown. The aim of this retrospective, cross-sectional study was to determine the mechanistic association between diastolic hydraulic forces, estimated by echocardiography as the atrioventricular area difference (AVAD), and both diastolic function and survival. Patients (n = 5176, median [interquartile range] 5.5 [5.0-6.1] years follow-up, 1213 events) were selected from the National Echo Database Australia (NEDA) based on the presence of relevant transthoracic echocardiographic measures, LV ejection fraction (LVEF) ≥ 50%, heart rate 50-100 beats/minute, the absence of moderate or severe valvular disease, and no prior prosthetic valve surgery. NEDA contains echocardiographic and linked national death index mortality outcome data from 1985 to 2019. AVAD was calculated as the cross-sectional area difference between the LV and left atrium. LV diastolic dysfunction was graded according to 2016 guidelines. AVAD was weakly associated with E/e', left atrial volume index, and LVEF (multivariable global R2 = 0.15, p < 0.001), and not associated with e' and peak tricuspid regurgitation velocity. Decreased AVAD was independently associated with poorer survival, and demonstrated improved model discrimination after adjustment for diastolic function grading (C-statistic [95% confidence interval] 0.644 [0.629-0.660] vs 0.606 [0.592-0.621], p < 0.001) and E/e' (0.649 [0.635-0.664] vs 0.634 [0.618-0.649], p < 0.001), respectively. Therefore, decreased hydraulic forces, estimated by AVAD, are weakly associated with diastolic dysfunction and demonstrate an incremental prognostic association with survival beyond conventional measures used to grade diastolic dysfunction.

Three Ablation Techniques for Atrial Fibrillation during Concomitant Cardiac Surgery: A Systematic Review and Network Meta-Analysis

Atrial fibrillation (AF) ablation is a frequent procedure used in concomitant cardiac surgery. However, uncertainty still exists concerning the optimal extent of lesion sets. Hence, the objective of this study was to assess the results of various ablation techniques, aiming to offer a reference for clinical decision making. This review is listed in the prospective register of systematic reviews (PROSPERO) under ID CRD42023412785. A comprehensive search was conducted across eight databases (Scopus, Google Scholar, EBSCOHost, PubMed, Medline, Wiley, ProQuest, and Embase) up to 18 April 2023. Studies were critically appraised using the Cochrane Risk of Bias 2.0 for randomized control trials (RCTs) and the Newcastle Ottawa Scale adapted by the Agency for Healthcare Research and Quality (AHRQ) for cohort studies. Forest plots of pooled effect estimates and surface under the cumulative ranking (SUCRA) were used for the analysis. Our analysis included 39 studies and a total of 7207 patients. Both bi-atrial ablation (BAA) and left atrial ablation (LAA) showed similar efficacy in restoring sinus rhythm (SR; BAA (77.9%) > LAA (76.2%) > pulmonary vein isolation (PVI; 66.5%); LAA: OR = 1.08 (CI 0.94-1.23); PVI: OR = 1.36 (CI 1.08-1.70)). However, BAA had higher pacemaker implantation (LAA: OR = 0.51 (CI 0.37-0.71); PVI: OR = 0.52 (CI 0.31-0.86)) and reoperation rates (LAA: OR = 0.71 (CI 0.28-1.45); PVI: OR = 0.31 (CI 0.1-0.64)). PVI had the lowest efficacy in restoring SR and a similar complication rate to LAA, but had the shortest procedure time (Cross-clamp (Xc): PVI (93.38) > LAA (37.36) > BAA (13.89)); Cardiopulmonary bypass (CPB): PVI (93.93) > LAA (56.04) > BAA (0.03)). We suggest that LAA is the best surgical technique for AF ablation due to its comparable effectiveness in restoring SR, its lower rate of pacemaker requirement, and its lower reoperation rate compared to BAA. Furthermore, LAA ranks as the second-fastest procedure after PVI, with a similar CPB time.

The «labyrinth» operative procedure with the left atrium plasty in correction of isolated failure of a mitral valve

Objective. To study the possibilities of the «labyrinth» procedure in combination with the left atrium reduction. Materials and methods. Into the investigation 261 patients, suffering isolated failure of a mitral valve Stage IV, operated in the National Institute of Cardio-Vascular Surgery n. a. M. M. Amosov, were included. The left atrium plasty with objective to reduce and prevent the waves spread re-entry was performed in 139 (53.2%) patients. Fragmentation in the left atrium was made in regime of low radiofrequencies (25 - 35 Вт) in accordance to schemes of Maze ІІІ, ІV. Results. In the hospital period 5 patients died (the hospital lethality have constituted 1.9%). While discharge from the hospital the sinus rhythm was noted in majority of the patients after the left atrium plasty, than in the alternative group - in 119 (85.6%) of 139 and in 79 (64.8%) of 122 patients, accordingly. Conclusion. The «labyrinth» procedure in combination with the left atrium plasty owes significant clinical advantages, including restoration and persistence of the sinus rhythm in patients, suffering pathology of a mitral valve.