Randomized study of surgery for patients with permanent atrial fibrillation as a result of mitral valve disease

Safety and efficacy of Cox-Maze procedure for atrial fibrillation during mitral valve surgery: a meta-analysis of randomized controlled trials

BACKGROUND

Cox-Maze procedure is currently the gold standard treatment for atrial fibrillation (AF). However, data on the effectiveness of the Cox-Maze procedure after concomitant mitral valve surgery (MVS) are not well established. The aim of this study was to assess the safety and efficacy of Cox-Maze procedure versus no-maze procedure n in AF patients undergoing mitral valve surgery through a systematic review of the literature and meta-analysis.

METHODS

A systematic search on PubMed/MEDLINE, EMBASE, and Cochrane Central Register of Clinical Trials (Cochrane Library, Issue 02, 2017) databases were performed using three databases from their inception to March 2023, identifying all relevant randomized controlled trials (RCTs) comparing Cox-Maze procedure versus no procedure in AF patients undergoing mitral valve surgery. Data were extracted and analyzed according to predefined clinical endpoints.

RESULTS

Nine RCTs meeting the inclusion criteria were included in this systematic review with 663 patients in total (341 concomitant Cox-Maze with MVS and 322 MVS alone). Across all studies with included AF patients undergoing MV surgery, the concomitant Cox-Maze procedure was associated with significantly higher sinus rhythm rate at discharge, 6 months, and 12 months follow-up when compared with the no-Maze group. Results indicated that there was no significant difference between the Cox-Maze and no-Maze groups in terms of 1 year all-cause mortality, pacemaker implantation, stroke, and thromboembolism.

CONCLUSIONS

Our systematic review suggested that RCTs have demonstrated the addition of the Cox-Maze procedure for AF leads to a significantly higher rate of sinus rhythm in mitral valve surgical patients, with no increase in the rates of mortality, pacemaker implantation, stroke, and thromboembolism.

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.

Efficiency and safety of ablation procedure for the treatment of atrial fibrillation in valve surgery: A PRISMA-compliant cumulative systematic review and meta-analysis

BACKGROUND

Atrial fibrillation is the main complication of patients who suffer from valvular heart disease (VHD), which may lead to an increased susceptibility to ventricular tachycardia, atrial dysfunction, heart failure, and stroke. Therefore, seeking a safe and effective therapy is crucial in prolonging the lives of patients with VHD and improving their quality of life.

METHODS

Our target database included PubMed, Web of Science, Embase, and Cochrane Library, from which published articles were retrieved from inception to June 2020. We retrieved all randomized controlled trials (RCTs) that compared patients undergoing valve surgery with (VSA) or without ablation (VS) procedure. Studies to be included were screened and data extraction was performed independently by 2 investigators. The Cochrane risk-of-bias table was used to evaluate the methodological quality of the included RCTs. The mean difference (MD) with 95% confidence interval (CI) and relative risk (RR) ratio was calculated to analyze the data. Heterogeneity was evaluated using I2 and chi-square tests. Egger test and the trim and fill analysis were used to further determine publication bias.

RESULTS

Fourteen RCTs that included 1376 patients were eventually selected for this meta-analysis. Surgical ablation was found to be effective in restoring sinus rhythm in valvular surgery patients at discharge (RR 2.91, 95% CI [1.17, 7.20], I2 97%, P = .02), 3 to 6 months (RR 2.85, 95% CI [2.27, 3.58], I2 49%, P < .00001), 12 months, and more than 1 year after surgery (RR 3.54, 95% CI [2.78, 4.51], I2 27%, P < .00001). All-cause mortality (RR 0.98, 95% CI [0.64, 1.51], I2 0%, P = .94) and stroke (RR 1.29, 95% CI [0.70, 2.39], I2 0%, P = .57) were similar in the VSA and VS groups. Compared with VS, VSA prolonged cardiopulmonary bypass time (MD 30.44, 95% CI [17.55, 43.33], I2 88%, P < .00001) and aortic cross-clamping time (MD 19.57, 95% CI [11.10, 28.03], I2 89%, P < .00001). No significant differences were found between groups with respect to the risk of bleeding (RR 0.64, 95% CI [0.37, 1.12], I2 0%, P = .12), heart failure (RR 1.11, 95% CI [0.63, 1.93], I2 0%, P = .72), and low cardiac output syndrome (RR 1.41, 95% CI [0.57, 3.46], I2 18%, P = .46). However, the demand for implantation of a permanent pacemaker was significantly higher in the VSA group (RR 1.84, 95% CI [1.15, 2.95], I2 0%, P = .01).

CONCLUSION

Although we found high heterogeneity in the restoration of sinus rhythm at discharge, we assume that the comparison is valid at this time, given the current state in the operating room. This study provides evidence of the efficacy and security of concomitant ablation intervention for patients with VHD and atrial fibrillation. Surgical ablation would increase the safety of implantation of a permanent pacemaker in the population that underwent valve surgery.

Three-year outcomes of the postapproval study of the AtriCure Bipolar Radiofrequency Ablation of Permanent Atrial Fibrillation Trial

OBJECTIVES

The Cox Maze IV operation is commonly performed concomitant with other cardiac operations and effectively reduces the burden of atrial fibrillation. Prospective randomized trials have reported outcomes early and at 12 months, but only single-center late durability results are available. As part of the postapproval process for a bipolar radiofrequency ablation system, we sought to determine early and midterm outcomes of patients undergoing the Cox Maze IV operation.

METHODS

A prospective, multicenter, single-arm study of 363 patients (mean age, 70 years, 82% valve surgery) with nonparoxysmal atrial fibrillation (mean duration, 60 months, 94% Congestive heart failure, Hypertension, Age ≥ 75, Diabetes, Stroke, VAScular disease, Age 65-74, Sex category ≥2) undergoing concomitant Maze IV atrial fibrillation ablation at 40 sites with 70 surgeons was performed between June 2010 and October 2014. Compliance with the study lesion set was 94.5%, and 99% had left atrial appendage closure. Freedom from atrial fibrillation was determined by extended monitoring, with a 48-hour Holter monitor minimum.

RESULTS

There were no device-related complications. Freedom from atrial fibrillation off antiarrhythmic medications at 1, 2, and 3 years was 66%, 65%, and 64%, respectively, and including those using antiarrhythmics was 80%, 78%, and 76%, respectively. Warfarin was used in 49%, 44%, and 40%, respectively.

CONCLUSIONS

In patients with nonparoxysmal atrial fibrillation, compliance with the protocol was high, and freedom from atrial fibrillation off antiarrhythmics was high and sustained to 3 years. The safety and effectiveness of the system and Cox Maze IV procedure support the Class I guideline recommendation for concomitant atrial fibrillation ablation in patients undergoing cardiac surgery.

Amaze: a double-blind, multicentre randomised controlled trial to investigate the clinical effectiveness and cost-effectiveness of adding an ablation device-based maze procedure as an adjunct to routine cardiac surgery for patients with pre-existing atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) can be treated using a maze procedure during planned cardiac surgery, but the effect on clinical patient outcomes, and the cost-effectiveness compared with surgery alone, are uncertain.

OBJECTIVES

To determine whether or not the maze procedure is safe, improves clinical and patient outcomes and is cost-effective for the NHS in patients with AF.

DESIGN

Multicentre, Phase III, pragmatic, double-blind, parallel-arm randomised controlled trial. Patients were randomised on a 1 : 1 basis using random permuted blocks, stratified for surgeon and planned procedure.

SETTING

Eleven acute NHS specialist cardiac surgical centres.

PARTICIPANTS

Patients aged ≥ 18 years, scheduled for elective or in-house urgent cardiac surgery, with a documented history (> 3 months) of AF.

INTERVENTIONS

Routine cardiac surgery with or without an adjunct maze procedure administered by an AF ablation device.

MAIN OUTCOME MEASURES

The primary outcomes were return to sinus rhythm (SR) at 12 months and quality-adjusted life-years (QALYs) over 2 years after randomisation. Secondary outcomes included return to SR at 2 years, overall and stroke-free survival, drug use, quality of life (QoL), cost-effectiveness and safety.

RESULTS

Between 25 February 2009 and 6 March 2014, 352 patients were randomised to the control (n = 176) or experimental (n = 176) arms. The odds ratio (OR) for return to SR at 12 months was 2.06 [95% confidence interval (CI) 1.20 to 3.54; p = 0.0091]. The mean difference (95% CI) in QALYs at 2 years between the two trial arms (maze/control) was -0.025 (95% CI 0.129 to 0.078; p = 0.6319). The OR for SR at 2 years was 3.24 (95% CI 1.76 to 5.96). The number of patients requiring anticoagulant drug use was significantly lower in the maze arm from 6 months after the procedure. There were no significant differences between the two arms in operative or overall survival, stroke-free survival, need for cardioversion or permanent pacemaker implants, New York Heart Association Functional Classification (for heart failure), EuroQol-5 Dimensions, three-level version score and Short Form questionnaire-36 items score at any time point. Sixty per cent of patients in each trial arm had a serious adverse event (p = 1.000); most events were mild, but 71 patients (42.5%) in the maze arm and 84 patients (45.5%) in the control arm had moderately severe events; 31 patients (18.6%) in the maze arm and 38 patients (20.5%) in the control arm had severe events. The mean additional cost of the maze procedure was £3533 (95% CI £1321 to £5746); the mean difference in QALYs was -0.022 (95% CI -0.1231 to 0.0791). The maze procedure was not cost-effective at £30,000 per QALY over 2 years in any analysis. In a small substudy, the active left atrial ejection fraction was smaller than that of the control patients (mean difference of -8.03, 95% CI -12.43 to -3.62), but within the predefined clinically equivalent range.

LIMITATIONS

Low recruitment, early release of trial summaries and intermittent resource-use collection may have introduced bias and imprecise estimates.

CONCLUSIONS

Ablation can be practised safely in routine NHS cardiac surgical settings and increases return to SR rates, but not survival or QoL up to 2 years after surgery. Lower anticoagulant drug use and recovery of left atrial function support anticoagulant drug withdrawal provided that good atrial function is confirmed.

FURTHER WORK

Continued follow-up and long-term clinical effectiveness and cost-effectiveness analysis. Comparison of ablation methods.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN82731440.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 19. See the NIHR Journals Library website for further project information.

Outcomes of Surgical Ablation in Patients With Atrial Fibrillation Undergoing Cardiac Surgeries

BACKGROUND

Surgical ablation procedure is commonly performed in patients with atrial fibrillation (AF) undergoing cardiac surgeries; however, the evidence regarding its impact on in-hospital cardiovascular outcomes is controversial.

METHODS

We queried the Nationwide Inpatient Sample Database for patients with AF who underwent cardiac surgeries from 1998 to 2013. We performed a propensity-score matching including 21 various baseline characteristics to compare those who underwent surgical ablation with those who had not.

RESULTS

A total of 47,964 hospitalizations were included in our final analysis. On propensity matching, 23,975 were in the surgical ablation group and 23,990 in the control group. The primary outcome of in-hospital mortality was lower in the surgical ablation group compared with the control group (3.6% versus 4.2%, p < 0.001). The surgical ablation group was associated with lower in-hospital cerebrovascular accident (2.0% versus 2.8%, p < 0.001), cardiogenic shock (2.6% versus 3.6%, p < 0.001), use of intraaortic balloon pump (5.1% versus 5.8%, p = 0.001), and shorter length of hospital stay (12.3 ± 10.1 versus 12.5 ± 10.3 days, p = 0.008). There was no difference between the surgical ablation and control groups in the incidence of cardiac tamponade (0.4% versus 0.3%, p = 0.296). The surgical ablation group was associated with a higher rate of complete heart block (5.2% versus 4.3%, p < 0.001) and permanent pacemaker insertion (8.6% versus 8.0%, p = 0.01).

CONCLUSIONS

In this large analysis of almost 50,000 patients with AF undergoing cardiac surgery, surgical ablation appears to be safe in the short term. Future studies should focus on evaluating the long-term effectiveness of this procedure.

Biatrial maze procedure versus pulmonary vein isolation for atrial fibrillation during mitral valve surgery: New analytical approaches and end points

OBJECTIVE

To use novel statistical methods for analyzing the effect of lesion set on (long-standing) persistent atrial fibrillation (AF) in the Cardiothoracic Surgical Trials Network trial of surgical ablation during mitral valve surgery (MVS).

METHODS

Two hundred sixty such patients were randomized to MVS + surgical ablation or MVS alone. Ablation was randomized between pulmonary vein isolation and biatrial maze. During 12 months postsurgery, 228 patients (88%) submitted 7949 transtelephonic monitoring (TTM) recordings, analyzed for AF, atrial flutter (AFL), or atrial tachycardia (AT). As previously reported, more ablation than MVS-alone patients were free of AF or AF/AFL at 6 and 12 months (63% vs 29%; P < .001) by 72-hour Holter monitoring, without evident difference between lesion sets (for which the trial was underpowered).

RESULTS

Estimated freedom from AF/AFL/AT on any transmission trended higher after biatrial maze than pulmonary vein isolation (odds ratio, 2.31; 95% confidence interval, 0.95-5.65; P = .07) 3 to 12 months postsurgery; estimated AF/AFL/AT load (ie, proportion of TTM strips recording AF/AFL/AT) was similar (odds ratio, 0.90; 95% confidence interval, 0.57-1.43; P = .6). Within 12 months, estimated prevalence of AF/AFL/AT by TTM was 58% after MVS alone, and 36% versus 23% after pulmonary vein isolation versus biatrial maze (P < .02).

CONCLUSIONS

Statistical modeling using TTM recordings after MVS in patients with (long-standing) persistent AF suggests that a biatrial maze is associated with lower AF/AFL/AT prevalence, but not a lower load, compared with pulmonary vein isolation. The discrepancy between AF/AFL/AT prevalence assessed at 2 time points by Holter monitoring versus weekly TTM suggests the need for a confirmatory trial, reassessment of definitions for failure after ablation, and validation of statistical methods for assessing atrial rhythms longitudinally.

Management of atrial fibrillation in patients with rheumatic mitral stenosis

Atrial fibrillation (AF) is frequent in patients with rheumatic mitral stenosis (MS). Pressure overload leads to marked structural and electrical remodelling of left atrium. The frequency of persistent AF increases with age and paroxysmal, asymptomatic, AF seems even more frequent. The occurrence of AF worsens the haemodynamic tolerance of MS and markedly increases the risk of thromboembolic events. AF has a negative impact on the natural history of MS and on its outcome after commissurotomy. The respective indications of rhythm and rate control should be adapted to patient characteristics, particularly the consequences of MS, and take into account the high risk of recurrence of AF. Oral anticoagulant therapy is mandatory when AF complicates MS, regardless of its severity and CHA2DS2-VASc score. Non-vitamin K antagonists oral anticoagulants are not recommended in moderate-to-severe MS due to the lack of data. Percutaneous mitral commissurotomy does not appear to prevent the occurrence of AF in MS but should be considered as the first-line therapy when AF is associated with severe symptomatic MS, followed by the discussion of cardioversion or ablation. AF ablation should be considered in patients with mitral disease requiring intervention, but the ideal timing and techniques are difficult to determine due to the lack of appropriate specific randomised trials in patients with MS.

Left atrial concomitant surgical ablation for treatment of atrial fibrillation in cardiac surgery: A meta-analysis of randomized controlled trials

INTRODUCTION

Surgical ablation is a generally established treatment for patients with atrial fibrillation undergoing concomitant cardiac surgery. Left atrial (LA) lesion set for ablation is a simplified procedure suggested to reduce the surgery time and morbidity after procedure. The present meta-analysis aims to explore the outcomes of left atrial lesion set versus no ablative treatment in patients with AF undergoing cardiac surgery.

METHODS

A literature research was performed in six database from their inception to July 2017, identifying all relevant randomized controlled trials (RCTs) comparing left atrial lesion set versus no ablative treatment in AF patient undergoing cardiac surgery. Data were extracted and analyzed according to predefined clinical endpoints.

RESULTS

Eleven relevant RCTs were included for analysis in the present study. The prevalence of sinus rhythm in ablation group was significantly higher at discharge, 6-month and 1-year follow-up period. The morbidity including 30 day mortality, late all-cause mortality, reoperation for bleeding, permanent pacemaker implantation and neurological events were of no significant difference between two groups.

CONCLUSIONS

The result of our meta-analysis demonstrates that left atrial lesion set is an effective and safe surgical ablation strategy for AF patients undergoing concomitant cardiac surgery.

Concomitant atrial fibrillation surgery for people undergoing cardiac surgery

BACKGROUND

People with atrial fibrillation (AF) often undergo cardiac surgery for other underlying reasons and are frequently offered concomitant AF surgery to reduce the frequency of short- and long-term AF and improve short- and long-term outcomes.

OBJECTIVES

To assess the effects of concomitant AF surgery among people with AF who are undergoing cardiac surgery on short-term and long-term (12 months or greater) health-related outcomes, health-related quality of life, and costs.

SEARCH METHODS

Starting from the year when the first "maze" AF surgery was reported (1987), we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (March 2016), MEDLINE Ovid (March 2016), Embase Ovid (March 2016), Web of Science (March 2016), the Database of Abstracts of Reviews of Effects (DARE, April 2015), and Health Technology Assessment Database (HTA, March 2016). We searched trial registers in April 2016. We used no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials evaluating the effect of any concomitant AF surgery compared with no AF surgery among adults with preoperative AF, regardless of symptoms, who were undergoing cardiac surgery for another indication.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We evaluated the risk of bias using the Cochrane 'Risk of bias' tool. We included outcome data on all-cause and cardiovascular-specific mortality, freedom from atrial fibrillation, flutter, or tachycardia off antiarrhythmic medications, as measured by patient electrocardiographic monitoring greater than three months after the procedure, procedural safety, 30-day rehospitalisation, need for post-discharge direct current cardioversion, health-related quality of life, and direct costs. We calculated risk ratios (RR) for dichotomous data with 95% confidence intervals (CI) using a fixed-effect model when heterogeneity was low (I² ≤ 50%) and random-effects model when heterogeneity was high (I² > 50%). We evaluated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework to create a 'Summary of findings' table.

MAIN RESULTS

We found 34 reports of 22 trials (1899 participants) with five additional ongoing studies and three studies awaiting classification. All included studies were assessed as having high risk of bias across at least one domain. The effect of concomitant AF surgery on all-cause mortality was uncertain when compared with no concomitant AF surgery (7.0% versus 6.6%, RR 1.14, 95% CI 0.81 to 1.59, I² = 0%, 20 trials, 1829 participants, low-quality evidence), but the intervention increased freedom from atrial fibrillation, atrial flutter, or atrial tachycardia off antiarrhythmic medications > three months (51.0% versus 24.1%, RR 2.04, 95% CI 1.63 to 2.55, I² = 0%, eight trials, 649 participants, moderate-quality evidence). The effect of concomitant AF surgery on 30-day mortality was uncertain (2.3% versus 3.1%, RR 1.25 95% CI 0.71 to 2.20, I² = 0%, 18 trials, 1566 participants, low-quality evidence), but the intervention increased the risk of permanent pacemaker implantation (6.0% versus 4.1%, RR 1.69, 95% CI 1.12 to 2.54, I² = 0%, 18 trials, 1726 participants, moderate-quality evidence). Investigator-defined adverse events, including but limited to, need for surgical re-exploration or mediastinitis, were not routinely reported but were not different between the two groups (other adverse events: 24.8% versus 23.6%, RR 1.07, 95% CI 0.85 to 1.34, I² = 45%, nine trials, 858 participants), but the quality of this evidence was very low.

AUTHORS' CONCLUSIONS

For patients with AF undergoing cardiac surgery, there is moderate-quality evidence that concomitant AF surgery approximately doubles the risk of freedom from atrial fibrillation, atrial flutter, or atrial tachycardia off anti-arrhythmic drugs while increasing the risk of permanent pacemaker implantation. The effects on mortality are uncertain. Future, high-quality and adequately powered trials will likely affect the confidence on the effect estimates of AF surgery on clinical outcomes.

Surgical Treatment of Concomitant Atrial Fibrillation: Focus onto Atrial Contractility

BACKGROUND

Maze procedure aims at restoring sinus rhythm (SR) and atrial contractility (AC). This study evaluated multiple aspects of AC recovery and their relationship with SR regain after ablation.

METHODS

122 mitral and fibrillating patients underwent radiofrequency Maze. Rhythm check and echocardiographic control of biatrial contractility were performed at 3, 6, 12, and 24 months postoperatively. A multivariate Cox analysis of risk factors for absence of AC recuperation was applied.

RESULTS

At 2-years follow-up, SR was achieved in 79% of patients. SR-AC coexistence increased from 76% until 98%, while biatrial contraction detection augmented from 84 to 98% at late stage. Shorter preoperative arrhythmia duration was the only common predictor of SR-AC restoring, while pulmonary artery pressure (PAP) negatively influenced AC recuperation. Early AC restoration favored future freedom from arrhythmia recurrence. Minor LA dimensions correlated with improved future A/E value and vice versa. Right atrial (RA) contractility restoring favored better left ventricular (LV) performance and volumes.

CONCLUSIONS

SR and left AC are two interrelated Maze objectives. Factors associated with arrhythmia "chronic state" (PAP and arrhythmia duration) are negative predictors of procedural success. Our results suggest an association between postoperative LA dimensions and "kick" restoring and an influence of RA contraction onto LV function.

Modified Maze Procedure for Atrial Fibrillation as an Adjunct to Elective Cardiac Surgery: Predictors of Mid-Term Recurrence and Echocardiographic Follow-Up

The radiofrequency maze procedure achieves sinus rhythm in 45%-95% of patients treated for atrial fibrillation. This retrospective study evaluates mid-term results of the radiofrequency maze-performed concomitant to elective cardiac surgery-to determine sinus-rhythm predictive factors, and describes the evolution of patients' echocardiographic variables. From 2003 through 2011, 247 patients (mean age, 64 ± 9.5 yr) with structural heart disease (79.3% mitral disease) and atrial fibrillation underwent a concomitant radiofrequency modified maze procedure. Patients were monitored by 24-hour Holter at 3, 6, 12, and 24 months, then annually. Eighty-four mitral-valve patients underwent regular echocardiographic follow-up. Univariate and multivariate analysis for risk factors of maze failure were identified. The in-hospital mortality rate was 1.2%. During a median follow-up of 39.4 months, the late mortality rate was 3.6%, and pacemaker insertion was necessary in 26 patients (9.4%). Sinus rhythm was present in 63% of patients at the latest follow-up. Predictive factors for atrial fibrillation recurrence were arrhythmia duration (hazard ratio [HR]=1.296, P=0.045) and atrial fibrillation at hospital discharge (HR=2.03, P=0.019). The monopolar device favored maze success (HR=0.191, P <0.0001). Left atrial area and indexed left ventricular end-diastolic volume showed significant decrease both in sinus rhythm and atrial fibrillation patients. Early sinus rhythm conversion was associated with improved left ventricular ejection fraction. Concomitant radiofrequency maze procedure provided remarkable outcomes. Shorter preoperative atrial fibrillation duration, monopolar device use, and prompt treatment of arrhythmia recurrences increase the midterm success rate. Early sinus rhythm restoration seems to result in better left ventricular ejection fraction recovery.

Patients with minimal atrial fibrillation events should not undergo concomitant atrial ablation during open heart procedures

Several randomized controlled trials and meta-analyses have demonstrated improved freedom from atrial fibrillation with intraoperative atrial ablation. However, the increased bypass time and the risk for ablation-related complications should be weighed against the benefits in the decision-making. It is important to establish reasonable criteria to define candidates for surgical ablation. Furthermore, the efficacy and short- and long-term risks related to surgical ablation need to be considered. This article reviews the data on surgical ablation of atrial fibrillation as it pertains to these important issues. As shown the evidence does not support surgical ablation at the time of coronary artery bypass graft in some patients.

Surgical ablation of atrial fibrillation during mitral-valve surgery

BACKGROUND

Among patients undergoing mitral-valve surgery, 30 to 50% present with atrial fibrillation, which is associated with reduced survival and increased risk of stroke. Surgical ablation of atrial fibrillation has been widely adopted, but evidence regarding its safety and effectiveness is limited.

METHODS

We randomly assigned 260 patients with persistent or long-standing persistent atrial fibrillation who required mitral-valve surgery to undergo either surgical ablation (ablation group) or no ablation (control group) during the mitral-valve operation. Patients in the ablation group underwent further randomization to pulmonary-vein isolation or a biatrial maze procedure. All patients underwent closure of the left atrial appendage. The primary end point was freedom from atrial fibrillation at both 6 months and 12 months (as assessed by means of 3-day Holter monitoring).

RESULTS

More patients in the ablation group than in the control group were free from atrial fibrillation at both 6 and 12 months (63.2% vs. 29.4%, P<0.001). There was no significant difference in the rate of freedom from atrial fibrillation between patients who underwent pulmonary-vein isolation and those who underwent the biatrial maze procedure (61.0% and 66.0%, respectively; P=0.60). One-year mortality was 6.8% in the ablation group and 8.7% in the control group (hazard ratio with ablation, 0.76; 95% confidence interval, 0.32 to 1.84; P=0.55). Ablation was associated with more implantations of a permanent pacemaker than was no ablation (21.5 vs. 8.1 per 100 patient-years, P=0.01). There were no significant between-group differences in major cardiac or cerebrovascular adverse events, overall serious adverse events, or hospital readmissions.

CONCLUSIONS

The addition of atrial fibrillation ablation to mitral-valve surgery significantly increased the rate of freedom from atrial fibrillation at 1 year among patients with persistent or long-standing persistent atrial fibrillation, but the risk of implantation of a permanent pacemaker was also increased. (Funded by the National Institutes of Health and the Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT00903370.).

Surgical options in atrial fibrillation

Atrial fibrillation (AF) is not benign and its prevalence is increasing. The two main goals in management of atrial fibrillation are to optimize hemodynamics through rate or rhythm control and to prevent systemic thrombo-embolism. To date, these two goals are still sub-optimally achieved, raising the need for alternative methods and strategies both pharmacologically and through interventions. In this review, we discuss surgical strategies of achieving both goals with insights on the evolution and potential future of these strategies.

Comparing energy sources for surgical ablation of atrial fibrillation: a Bayesian network meta-analysis of randomized, controlled trials

Simplified maze procedures involving radiofrequency, cryoenergy and microwave energy sources have been increasingly utilized for surgical treatment of atrial fibrillation as an alternative to the traditional cut-and-sew approach. In the absence of direct comparisons, a Bayesian network meta-analysis is another alternative to assess the relative effect of different treatments, using indirect evidence. A Bayesian meta-analysis of indirect evidence was performed using 16 published randomized trials identified from 6 databases. Rank probability analysis was used to rank each intervention in terms of their probability of having the best outcome. Sinus rhythm prevalence beyond the 12-month follow-up was similar between the cut-and-sew, microwave and radiofrequency approaches, which were all ranked better than cryoablation (respectively, 39, 36, and 25 vs 1%). The cut-and-sew maze was ranked worst in terms of mortality outcomes compared with microwave, radiofrequency and cryoenergy (2 vs 19, 34, and 24%, respectively). The cut-and-sew maze procedure was associated with significantly lower stroke rates compared with microwave ablation [odds ratio <0.01; 95% confidence interval 0.00, 0.82], and ranked the best in terms of pacemaker requirements compared with microwave, radiofrequency and cryoenergy (81 vs 14, and 1, <0.01% respectively). Bayesian rank probability analysis shows that the cut-and-sew approach is associated with the best outcomes in terms of sinus rhythm prevalence and stroke outcomes, and remains the gold standard approach for AF treatment. Given the limitations of indirect comparison analysis, these results should be viewed with caution and not over-interpreted.

Surgical options for treatment of atrial fibrillation

If we want to improve the outcomes, increase the success and reduce the complication rate of existing treatment strategies in concomitant and stand-alone atrial fibrillation (AF) procedures, we will have to increase our understanding of the pathophysiology, and of the disease, the limitations of current energy sources and ablation catheters, the different possible lesion sets, as well as improve communication between the electrophysiologist and cardiac surgeon. The technical limitations of percutaneous endocardial ablation procedures and the empirical techniques in surgical AF procedures necessitate new and innovative approaches. Surgeons should aim to improve the quality of the lesion set and minimize the invasiveness of existing techniques. The Maze procedure remains the basis upon which most of the more limited concomitant ablation procedures are and will be designed, but in stand-alone patients, recent progress has directed us towards either a single-step or sequential combined percutaneous endocardial procedure with a thoracoscopic epicardial procedure on the beating heart. A dedicated team of electrophysiologists and cardiothoracic surgeons can now work together to perform AF procedures. This can guide us to determine if there is an additional value of limiting the lesion set of the Maze procedure in concomitant surgery, and of an epicardial access in the treatment of stand-alone AF on the beating heart. If so, we will better understand which energy sources, lesion sets and surgical techniques are able to give us a three-dimensional knowledge and a three-dimensional treatment of AF. As a result, we can expect to obtain a higher single procedure long-term success rate with an acceptable low complication rate.

Nonpharmacologic stroke prevention in atrial fibrillation

Atrial fibrillation is associated with significant mortality and morbidity. The burden of morbidity in atrial fibrillation is mostly due to stroke, one of the major causes of death and the leading cause of long-term disability. Although highly effective in prevention of thromboembolic stroke, several factors limit utilization of chronic oral anticoagulation therapy. Eradication of atrial fibrillation and restoration of effective atrial contraction by surgical methods, or recently, by percutaneous catheter ablation methods, are two attractive approaches for stroke prophylaxis. Surgical exclusion of the left atrial appendage has generated considerable interest in the past decades and it is now performed routinely during mitral valve surgery in many centers. Recently, minimally invasive and percutaneous methods for the exclusion of left atrial appendage have been introduced. Currently, these approaches are being evaluated in ongoing trials. This review will discuss the current status of nonpharmacologic methods in the prevention of stroke in atrial fibrillation.

Assessment of the adherence of cardiologists to guidelines for the treatment of atrial fibrillation

BACKGROUND

No local studies evaluating the knowledge of cardiologists on the management of atrial fibrillation (AF) and their adherence to these guidelines are available.

OBJECTIVE

To evaluate the knowledge of cardiologists on the guidelines and clinical practices for the treatment of AF, correlating it to the time since medical graduation.

METHODS

Cross-sectional study randomly including cardiologists affiliated to the Society of Cardiology of the State of Rio Grande do Sul (Sociedade de Cardiologia do Estado do Rio Grande do Sul - SOCERGS). The physicians were divided into two groups, according to time since graduation: those graduated for more (G1) or less (G2) than 25 years.

RESULTS

Of the 859 SOCERGS members, 150 were interviewed, and six refused to participate in the study. G1 comprised 71 physicians, and G2, 73. Differences were observed in regard to the following variables: use of betablockers as the first-choice drug for the control of AF response in 59.2% (G1) vs 91.8% (G2) (p<0.0001); use of digoxin as the preferred drug for the control of AF response in 19.7% (G1) vs 0% (G2) (p< 0.0001); warfarin as the preferred anticoagulant in 71.8% (G1) vs 93.2% (G2) (p=0.009); application of a risk score for anticoagulation in 73.2% (G1) vs 87.7% (G2) (p=0.02). In questions regarding the knowledge about the Brazilian Society of Cardiology's guideline for AF, the overall percentage of right answers was 82.3%.

CONCLUSION

Most of the clinical measures regarding the management of AF comply with the guidelines, and the clinical practice differs according with the time since graduation.

Design and rationale of the PRAGUE-12 trial: a large, prospective, randomized, multicenter trial that compares cardiac surgery with left atrial surgical ablation with cardiac surgery without ablation in patients with coronary and/or valvular heart disease plus atrial fibrillation

Surgical ablation procedure can restore sinus rhythm (SR) in patients with atrial fibrillation (AF) undergoing cardiac surgery. However, it is not known whether it has any impact on clinical outcomes. There is a need for a randomized trial with long‐term follow‐up to study the outcome of surgical ablation in patients with coronary and/or valve disease and AF. Patients are prospectively enrolled and randomized either to group A (cardiac surgery with left atrial ablation) or group B (cardiac surgery alone). The primary efficacy outcome is the SR presence (without any AF episode) during a 24‐hour electrocardiogram after 1 year. The primary safety outcome is the combined end point of death, myocardial infarction, stroke, and renal failure at 30 days. Long‐term outcomes are a composite of total mortality, stroke, bleeding, and heart failure at 1 and 5 years. We finished the enrollment with a total of 224 patients from 3 centers in 2 countries in December 2011. Currently, the incomplete 1‐year data are available, and the patients who enrolled first will have their 5‐year visits shortly. PRAGUE‐12 is the largest study to be conducted so far comparing cardiac surgery with surgical ablation of AF to cardiac surgery without ablation in an unselected population of patients who are operated on for coronary and/or valve disease. Its long‐term results will lead to a better recognition of ablation's potential clinical benefits.

The PRAGUE‐12 trial is partially funded by the Charles University Research Projects MSM0021620817 and UNCE 204010/2012.

The authors have no other funding, financial relationships, or conflicts of interest to disclose.

Comparison of cardiac surgery with left atrial surgical ablation vs. cardiac surgery without atrial ablation in patients with coronary and/or valvular heart disease plus atrial fibrillation: final results of the PRAGUE-12 randomized multicentre study

Aims

Surgical ablation procedure can restore sinus rhythm (SR) in patients with atrial fibrillation (AF) undergoing cardiac surgery. However, it is not known whether it has any impact on long-term clinical outcomes.

Methods and results

This multicentre study randomized 224 patients with AF scheduled for valve and/or coronary surgery: group A (left atrial surgical ablation, n = 117) vs. group B (no ablation, n = 107). The primary efficacy outcome was the SR presence (without any AF episode) during a 24 h electrocardiogram (ECG) after 1 year. The primary safety outcome was the combined endpoint of death/myocardial infarction/stroke/renal failure at 30 days. A Holter-ECG after 1 year revealed SR in 60.2% of group A patients vs. 35.5% in group B (P = 0.002). The combined safety endpoint at 30 days occurred in 10.3% (group A) vs. 14.7% (group B, P = 0.411). All-cause 1-year mortality was 16.2% (A) vs. 17.4% (B, P = 0.800). Stroke occurred in 2.7% (A) vs. 4.3% (B) patients (P = 0.319). No difference (A vs. B) in SR was found among patients with paroxysmal (61.9 vs. 58.3%) or persistent (72 vs. 50%) AF, but ablation significantly increased SR prevalence in patients with longstanding persistent AF (53.2 vs. 13.9%, P < 0.001).

Conclusion

Surgical ablation improves the likelihood of SR presence post-operatively without increasing peri-operative complications. However, the higher prevalence of SR did not translate to improved clinical outcomes at 1 year. Further follow-ups (e.g. 5-year) are warranted to show any potential clinical benefit which might occur later.

Microwave Ablation in Mitral Valve Surgery for Atrial Fibrillation (MAMA)

Objective: Microwave ablation in conjunction with open heart surgery is effective in restoring sinus rhythm (SR) in patients with atrial fibrillation (AF). In patients assigned for isolated mitral valve surgery no prospective randomized trial has reported its efficacy. Methods: 70 patients with longlasting AF where included from 5 different centres. They were randomly assigned to mitral valve surgery and atrial microwave ablation or mitral valve surgery alone. Results: Out of 70 randomized, 66 and 64 patients were available for evaluation at 6 and 12 months. At 12 months SR was restored and preserved in 71.0 % in the ablation group vs 36.4 % in the control group (P=0.006), corresponding figures at 6 months was 62.5 % vs 26.5 % (P=0.003). The 30-day mortality rate was 1.4 %, with one death in the ablation group vs zero deaths in the control group. At 12 months the mortality rate was 7,1 % (Ablation n=3 vs Control n=2). No significant differences existed between the groups with regard to the overall rate of serious adverse events (SAE) during the perioperative period or at the end of the study. 16 % of patients randomized to ablation were on antiarrhytmic drugs compared to 6 % in the control group after 1 year (p=0.22). Conclusion: Microwave ablation of left and right atrium in conjunction with mitral valve surgery is safe and effectively restores sinus rhythm in patients with longlasting AF as compared to mitral valve surgery alone.

Designing comparative effectiveness trials of surgical ablation for atrial fibrillation: experience of the Cardiothoracic Surgical Trials Network

OBJECTIVE

Since the introduction of the cut-and-sew Cox maze procedure for atrial fibrillation, there has been substantial innovation in techniques for ablation. Use of alternative energy sources for ablation simplified the procedure and has resulted in dramatic increase in the number of patients with atrial fibrillation treated by surgical ablation. Despite its increasingly widespread adoption, there is lack of rigorous clinical evidence to establish this procedure as an effective clinical therapy.

METHODS

This article describes a comparative effectiveness randomized trial, supported by the Cardiothoracic Surgical Clinical Trials Network, of surgical ablation with left atrial appendage closure versus left atrial appendage closure alone in patients with persistent and long-standing persistent atrial fibrillation undergoing mitral valve surgery. Nested within this trial is a further randomized comparison of 2 different lesions sets: pulmonary vein isolation and the full maze lesion set.

RESULTS

This article addresses trial design challenges, including how best to characterize the target population, operationalize freedom from atrial fibrillation as a primary end point, account for the impact of antiarrhythmic drugs, and measure and analyze secondary end points, such as postoperative atrial fibrillation load.

CONCLUSIONS

This article concludes by discussing how insights that emerge from this trial may affect surgical practice and guide future research in this area.

Surgical Maze procedure as a treatment for atrial fibrillation: a meta-analysis of randomized controlled trials

Surgical or modified Maze procedures have been promoted to treat atrial fibrillation (AF); however, few randomized controlled clinical trials (RCTs) examine their outcomes. The purpose of this meta-analysis is to compare the efficacy of surgical Maze procedures performed concomitantly with referral cardiac surgery versus pharmacologic therapy for the treatment of AF. We searched MEDLINE, Cochrane database, FDA web-portal, and clinicaltrials.gov for all RCTs comparing surgical Maze procedures with medical therapy for sinus rhythm maintenance. Primary outcomes were either freedom from AF within 12 months postprocedure off antiarrhythmic drug (AAD), or freedom from AF while taking an AAD. Secondary outcomes included operative mortality, all-cause mortality, hospital length of stay, and postoperative complications. Both fixed- and random-effects models were used for a meta-analysis of 9 randomized controlled trials (n = 472, of which 249 underwent a Maze procedure and 213 underwent referral surgery alone). The surgical Maze procedure significantly increased the odds of freedom from AF within 12 months compared with cardiac surgery alone (OR 5.22, 95% CI 1.71-15.88). There was significant heterogeneity among the trials for freedom from AF (chi-square = 15.98 for 4 degrees of freedom, P= 0.003). Among the two studies that fully reported AAD use, there was no evidence of improved survival free from AF and AAD therapy (OR 1.78, 95% CI 0.73-4.34). Among patients with valvular AF, surgical Maze procedures are associated with a decrease in AF one year postprocedure without significant increase in mean length of hospital stay, perioperative complications, operative, or all-cause mortality. Large RCTs defining rates of freedom from AF without AADs postprocedure, are still needed to evaluate outcomes and determine the appropriate role for surgical Maze procedures in the management of AF.

Comparison of surgical cut and sew versus radiofrequency pulmonary veins isolation for chronic permanent atrial fibrillation: a randomized study

BACKGROUND

Surgical pulmonary veins isolation (PVI) is done to restore sinus rhythm (SR) in patients with chronic permanent atrial fibrillation (CPAF) and mitral valve disease. Here we compare the efficacy of electrical block lines performed with radiofrequency (RF) compared with conventional surgery.

METHODS

Randomized trial of 22 patients with CPAF and indication for mitral valve surgery. Ten patients underwent conventional surgery (SURG) and 12 RF. To prove the efficacy of the blockage lines, epicardial pacemaker wires were placed in the isolated pulmonary veins region (IPVR) and right atria (RA).

RESULTS

There were no differences in the baseline data among the groups. All patients remained in SR during the immediate postoperative period. Block lines were tested in patients who remained in SR during the following days (eight in SURG and nine in RF). The median value of thresholds to conduct the stimulus of IPVR for the RA was 18 mA in SURG and 3 mA in RF (P < 0.022). Eight SURG patients and seven RF patients (P < 0.38) remained in SR at hospital discharge. Eleven RF patients and one SURG required amiodarone to maintain SR (P < 0.001). The incidence of recurrent atrial fibrillation (AF) in the follow-up was 10.7/100 patients/year in the SURG group versus 73.1/100 patients/year in the RF group (P = 0.009).

CONCLUSIONS

PVI by SURG formed more effective block lines than RF. SR at hospital discharge was similar among the groups, but more amiodarone was used in RF. During follow-up, incidence of recurrent AF was higher in the RF group.

Novel approaches for the surgical treatment of atrial fibrillation: time for a guideline revision?

Atrial fibrillation is a major health problem in Western countries, and is associated with considerable morbidity and resource consumption. Safe and reliable surgical techniques for the termination of this arrhythmia have been developed since the time of the original Cox "maze I" procedure. Novel equipment based on radiofrequency and microwave technologies can be employed to create transmural atrial lesions, even in the context of minimally invasive surgery to the atrioventricular valves via right minithoracotomy. The aim of this paper is to review the recent literature on this approach, and the clinical results in terms of arrhythmia termination and postoperative morbidity. With the aim to substantiate the practice of a simple, yet reliable, surgical ablation during minimally invasive heart valve surgery, we discuss the results of different patterns of atrial lesions having different degrees of surgical complexity. Finally, minimally invasive epicardial ablation for lone atrial fibrillation represents an emerging surgical indication. The results of state-of-the-art transcatheter ablation represent now its benchmark of comparison.

Surgical Ablation for Atrial Fibrillation in Cardiac Surgery a Consensus Statement of the International Society of Minimally Invasive Cardiothoracic Surgery (ISMICS) 2009

Objective

This purpose of this consensus conference was to determine whether surgical atrial fibrillation (AF) ablation during cardiac surgery improves clinical and resource outcomes compared with cardiac surgery alone in adults undergoing cardiac surgery for valve or coronary artery bypass grafting.

Methods

Before the consensus conference, the consensus panel reviewed the best available evidence, whereby systematic reviews, randomized trials, and nonrandomized trials were considered in descending order of validity and importance. Evidence-based statements were created, and consensus processes were used to determine the ensuing recommendations. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of recommendation.

Results

The consensus panel agreed on the following statements in patients with AF undergoing cardiac surgery concomitant surgical ablation: 1. Improves the achievement of sinus rhythm at discharge and 1 year (level A); this effect is sustained up to 5 years (level B). Does not reduce the use of antiarrhythmic drugs at 12 months after surgery (level A; 36.0% vs. 45.4%), although trials were not designed to answer this question. 2. Does not increase the requirement for permanent pacemaker implantation (4.4% vs. 4.8%; level A). 3. Does not increase the risk of perioperative mortality (level A), stroke (level A), myocardial infarction (level B), cardiac tamponade (level A), reoperative bleeding (level A), esophageal injury (level B), low cardiac output (level A), intraaortic balloon (level B), congestive heart failure (level B), ejection fraction (EF; level B), pleural effusion (level A), pneumonia (level A), renal dysfunction (level B), and mediastinitis (level A). The incidence of esophageal injury remains to be low (level B). 4. Does not reduce mortality at 1 year (level A). There is a possible reduction in mortality beyond 1 year (level B), but no difference in stroke (level A), myocardial infarction (level A), and heart failure (level B). EF is increased (+4.1% more than control; level A). 5. Has been shown to improve exercise tolerance at 1 year (level A), but no impact on quality of life at 3 months and 1 year (level A); however, the methodology used and the number of trials studying these outcomes are insufficient. 6. Increases cardiopulmonary bypass and cross-clamp times (level A), with no difference in intensive care unit and hospital length of stay (level A). Overall costs were not reported.

Conclusions

Given these evidence-based statements, the consensus panel stated that, in patients with persistent and permanent AF undergoing cardiac surgery, concomitant surgical ablation is recommended to increase incidence of sinus rhythm at short- and long-term follow-up (class 1, level A); to reduce the risk of stroke and thromboembolic events (class 2a, level B); to improve EF (class 2a, level A); and to exercise tolerance (class 2a, level A) and long-term survival (class 2a, level B).

Surgical Ablation for Atrial Fibrillation in Cardiac Surgery a Meta-Analysis and Systematic Review

Objectives

This meta-analysis sought to determine whether surgical ablation improves clinical outcomes and resource utilization compared with no ablation in adult patients with persistent and permanent atrial fibrillation (AF) undergoing cardiac surgery.

Methods

A comprehensive search was undertaken to identify all randomized (RCT) and nonrandomized (non-RCT) controlled trials of surgical ablation versus no ablation in patients with AF undergoing cardiac surgery up to April 2009. The primary outcome was sinus rhythm. Secondary outcomes included survival and any other reported clinically relevant outcome or indicator of resource utilization. Odds ratios (OR) and weighted mean differences (WMD) and their 95% confidence intervals (95% CI) were analyzed as appropriate using the random effects model. Heterogeneity was measured using the I2 statistic. Meta-regression was performed to explore the relationship between the benefit from surgical AF and duration of follow-up.

Results

Thirty-three studies met the inclusion criteria (10 RCTs and 23 non-RCTs) for a total of 4647 patients. The number of patients in sinus rhythm was significantly improved at discharge in the surgical AF ablation group versus (68.6%) the surgery alone group (23.0%) in RCTs (OR 10.1, 95% CI 4.5–22.5) and non-RCTs (OR 7.15, 95% CI 3.42–14.95). This effect on sinus rhythm (74.6% vs. 18.4%) remained at follow-up of 1 to 5 years (OR 6.7, 95% CI 2.8–15.7 for RCT, and OR 15.5, 95% CI 6.6–36.7 for non-RCT). The risk of all-cause mortality at 30 days was not different between the groups in RCT (OR 1.20, 95% CI 0.52–3.16) or non-RCT studies (OR 0.99, 95% CI 0.52–1.87). In studies reporting all-cause mortality at 1 year or more (up to 5 years), mortality did not differ in RCT studies (OR 1.21, 95% CI 0.59–2.51) but was significantly reduced in non-RCT studies (OR 0.54, 95% CI 0.31–0.96). Stroke incidence was not reduced significantly; however, in meta-regression, the risk of stroke decreased significantly with longer follow-up. Other clinical outcomes were similar between groups. Operation time was significantly increased with surgical AF ablation; however, overall impact on length of stay was variable.

Conclusions

In patients with persistent or permanent AF who present for cardiac surgery, the addition of surgical AF ablation led to a significantly higher rate of sinus rhythm in RCT and non-RCT studies compared with cardiac surgery alone, and this effect remains robust over the longer term (1–5 years). Although non-RCT studies suggest the possibility of reduced risk of stroke and death, this remains to be proven in prospective RCTs with adequate power and follow-up.

Left atrial radiofrequency ablation during mitral valve surgery: a prospective randomized multicentre study (SAFIR)

BACKGROUND

Randomized studies evaluating left atrial radiofrequency ablation (RFA) in patients with persistent atrial fibrillation undergoing mitral valve surgery are scarce and monocentric.

AIM

To evaluate the efficacy of left atrial RFA concomitant with mitral valve surgery to restore and maintain sinus rhythm.

METHODS

The SAFIR is a multicentre, double-blinded, centrally randomized study involving four university hospitals. Between December 2002 and September 2005, 43 patients with mitral valve disease and long-standing, persistent atrial fibrillation (duration>6 months) were included. We compared valvular surgery alone (n=22) or with left atrial RFA (n=21). The main endpoint was sinus rhythm at 12 months without recurrence of arrhythmia during follow-up. Secondary endpoints were surgical adverse events, atrial fibrillation relapses, stroke and echocardiographic measurements after three and 12 months' follow-up. Analyses of the efficacy criteria were performed on an intention-to-treat basis.

RESULTS

The primary endpoint occurred significantly more often in the RFA group than in the control group (respectively, 12/21 patients [57%] vs 1/22 patients [4%]; p=0.004). There were more patients with sinus rhythm in the RFA group than in the control group at discharge (72.7% vs 4.8%; p<0.005), 3-month follow-up (85.7% vs 23.8%; p<0.01) and 12-month follow-up (95.2% vs 33.3%; p<0.005). The patients in the RFA group had similar rates of postoperative complications and stroke during follow-up as those in the control group.

CONCLUSIONS

This multicentre study suggests that left atrial RFA is effective and safe in patients with chronic atrial fibrillation and mitral valve disease.

Randomized study of surgical isolation of the pulmonary veins for correction of permanent atrial fibrillation associated with mitral valve disease

OBJECTIVE

Chronic permanent atrial fibrillation is often due to mitral valve disease. The Cox maze procedure is the gold standard for treating this arrhythmia. Simpler techniques and ablation methods should have their efficacy tested in clinical practice. Our objective was to evaluate the effectiveness of surgical pulmonary vein isolation as compared with the Cox maze procedure.

METHODS

Sixty patients were randomly assigned to control group, modified maze group (Cox maze III), and surgical isolation of the pulmonary veins (SPVI) group from July 1999 to October 2004. All patients had mitral valve lesions treated concomitantly. Preoperative characteristics were similar between groups.

RESULTS

There were 4 deaths: 3 in the Cox maze group and 1 in the SPVI group (P = .31). The Cox maze group presented longer times of extracorporeal circulation and myocardial ischemia (P < .001). The relative risk of late postoperative development of atrial fibrillation was 0.07 in the SPVI group (P < .001; 95% confidence intervals: 0.02-0.27) and 0.195 in the Cox maze group (P = .002; 95% confidence intervals: 0.07-0.56) as compared with the control group. No difference was found between the SPVI and Cox maze groups concerning prevention of atrial fibrillation recurrence (relative risk: 0.358; P = .215; 95% confidence intervals: 0.08-1.67).

CONCLUSIONS

The modified Cox maze procedure and surgical pulmonary vein isolation were similarly effective in restoring sinus or regular rhythm in permanent atrial fibrillation associated with mitral valve disease. These results favor the adoption of surgical isolation as a preferable technique, simpler and equally effective in controlling atrial fibrillation. The results also can bring further information for understanding the mechanisms involved in origins and treatment of chronic permanent atrial fibrillation.

Intermediate to long-term results of radiofrequency modified Maze procedure as an adjunct to open-heart surgery

BACKGROUND

Of patients scheduled for elective open heart surgery, a substantial number of patients have preoperative atrial fibrillation (AF). The cut-and-sew Maze procedure and variant Maze procedures abolish AF in 45% to 95% during short- to intermediate-term follow-up. Limited data are available about maintenance of sinus rhythm during intermediate- to long-term follow-up. The objective of the present study was to assess the association between postoperative rhythm and mortality and stroke.

METHODS

From November 1995 to November 2003, 258 patients with structural heart disease and permanent AF with a duration of longer than 12 months were scheduled for elective cardiac surgery and included in a registry. They underwent a radiofrequency modified Maze procedure as an adjunct to the open heart operation. Patients were followed in the outpatient clinic, and follow-up data were obtained from medical correspondence of attending physicians. For this paper, follow-up ended November 2006; however, patients are being followed in an ongoing registry.

RESULTS

Two hundred fifty-eight patients (mean age, 68.1 +/- 9.5 years) with permanent AF underwent cardiac surgical procedures and concomitant radiofrequency Maze surgery; 213 patients (82.5%) underwent more than one procedure. Mean duration of permanent AF was 66.6 +/- 69.8 months (range, 16 to 96). Preoperatively, 82.9% of patients were in New York Heart Association class III. In-hospital mortality was 3.9% (10 patients), and during a mean follow-up of 43.7 +/- 25.9 months (range, 27 to 114), 73 patients (28.3%) died. Left ventricular ejection fraction was normal in 44.6%, moderately decreased in 42.5%, and poor in 12.9% of patients. Sustained sinus rhythm, including atrial rhythm or an atrial-based paced rhythm was present in 69% of patients at 1 year, in 56% at 3 years, in 52% at 5 years, and in 57% of patients at the latest follow-up. Antiarrhythmic drugs were used by 64% of survivors who were free of atrial fibrillation. Oral anticoagulation therapy was taken by 99% of patients. Stroke was reported in 4 patients (1.6%).

CONCLUSIONS

The RF modified Maze procedure abolishes AF in the majority of patients with structural heart disease and longstanding permanent AF. Postoperative rhythm was not predictive of all-cause mortality, cardiac mortality, and stroke, neither in the whole group nor in the subgroups defined by preoperative left ventricular ejection fraction and New York Heart Association class. The stroke rate was very low in this group with longstanding AF.

Long-term results after ablation for long-standing atrial fibrillation concomitant to surgery for organic heart disease: is microwave energy reliable?

OBJECTIVE

Microwave ablation has been reported as efficient for the surgical treatment of long-standing atrial fibrillation. However, the influence of ablation lesions on long-term results is not known.

METHODS

From August of 2000 to November of 2003, 41 patients underwent a left atrial endocardial microwave ablation procedure after a Cox-Maze-like lesion set for long-standing atrial fibrillation concomitant to surgery for valvular or coronary artery disease. Mitral valve surgery alone or combined was performed in 31 cases (75.6%). The mean diameter of the left atrium was 7.19 +/- 1.44 cm. The mean duration of preoperative atrial fibrillation was 4.7 +/- 3.6 years. Patient follow-up was conducted by means of direct clinical examination, electrocardiography, and transthoracic echocardiography. The mean follow-up was 5.37 +/- 0.91 years.

RESULTS

Patient follow-up was achieved in 82% of cases (n = 28). Seven patients (17%) died during follow-up. Stroke was the cause of death in 1 patient with persistence of atrial fibrillation. Major complications occurred in 4 (14.3%) of the patients that were related to the persistence of atrial fibrillation. At 5 years follow-up, 39.3% of patients (11/28) were in sinus rhythm. Seventeen patients (60.7%) were in New York Heart Association classes I and II, and 11 patients (39.3%) were in New York Heart Association class III at the time of follow-up.

CONCLUSION

In our experience, left atrial endocardial microwave ablation for long-standing atrial fibrillation after a Cox-Maze-like ablation lesion set during surgery for organic heart disease is not a reliable method of achieving long-term conversion to sinus rhythm.