A new procedure for elimination of atrial fibrillation associated with mitral valve disease: a proof-of-concept study

BACKGROUND

Left atrial enlargement and fibrosis have been linked to the pathogenesis of atrial fibrillation (AF). The authors aimed to introduce a novel concept and develop a new procedure for AF treatment based on these characteristics.

METHODS

The study included three stages. The first stage was a descriptive study to clarify the characteristics of the left atrial enlargement and fibrosis' distribution in patients with mitral valve disease and long-standing persistent AF. Based on these characteristics, the authors introduced a novel concept for AF treatment, and then translated it into a new procedure. The second stage was a proof-of-concept study with this new procedure. The third stage was a comparative effectiveness research to compare the clinical outcomes between patients with this new procedure and those who received Cox-Maze IV treatment.

RESULTS

Based on the nonuniform fashion of left atrial enlargement and fibrosis' distribution, the authors introduced a novel concept: reconstructing a left atrium with appropriate geometry and uniform fibrosis' distribution for proper cardiac conduction, and translated it into a new procedure: left atrial geometric volume reduction combined with left appendage base closure. As compared to the Cox-Maze IV procedure, the new procedure spent significantly shorter total surgery time, cardiopulmonary bypass time, and aortic cross-clamp time ( P <0.001). Besides, the new procedure was related to a shorter ICU stay period (odd ratio (OR)=0.45, 95% CI=0.26-0.78), lower costs (OR=0.15, 95% CI=0.08-0.29), and a higher rate of A wave of transmitral and transtricuspid flow reappearance (OR=1.76, 95% CI=1.02-3.04).

CONCLUSIONS

The new procedure is safe and effective for eliminating AF associated with mitral valve disease.

The first experience of a hybrid approach in the surgical treatment of atrial fibrillation

Background: Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is associated with an increased risk of death, progression of heart failure, and the development of cardiogenic thromboemboli. Despite the significant success in the management of AF in the paroxysmal form, the results of the treatment for patients with persistent forms of AF remain unsatisfactory. Though the surgical approach provides higher rates of efficiency regarding the restoration of a sinus rhythm, transmural lesions are not always attainable, as a result, the rate of AF recurrence in the long-term period remains fairly high. It is also impossible to create ablative patterns to the mitral and tricuspid valves during thoracoscopic epicardial ablation, which can cause the development of recurrent AF, perimitral and typical atrial flutter. Therefore, the development of hybrid approaches combining the advantages of catheter and thoracoscopic techniques is an urgent task of contemporary surgical and interventional arrhythmology. Aims: to estimate the immediate results of a hybrid approach in the management of patients with persistent AF. Methods: We report the first experience of a hybrid treatment of patients with persistent AF. 6 patients aged 53-64 years (1 female, 5 males) were included in the study. At the first stage, thoracoscopic epicardial bipolar ablation was performed (modified GALAXY protocol); the second stage (in 3 to 6 months after the thoracoscopic stage) included an intracardiac electrophysiological study with three-dimensional endocardial mapping followed by endocardial ablation. Results: The thoracoscopic stage of the hybrid treatment included ablation according to the box lesion scheme using a bipolar irrigation equipment. No lethal outcomes and severe, life-threatening complications were registered. The duration of the inpatient period was 510 hospital-days. The 2nd stage of the hybrid treatment was limited to intracardiac electrophysiological examination only in 2 patients. In 4 patients, epicardial radiofrequency ablation was complemented by endocardial radiofrequency exposure. In 3 of the 4 patients who underwent endocardial radiofrequency ablation, catheter ablation of the mitral and cavotricuspid isthmus was required because of the induction of perimitral and typical flutter, respectively. After the 2nd stage of the hybrid treatment, at the time of discharge all the patients maintained a stable sinus rhythm. There were no severe complications or lethal outcomes. Conclusion: a hybrid approach in the AF management is a safe and effective method of treatment, which combines the advantages of minimally invasive surgery and endocardial intervention in patients with persistent AF. The technique is safe and has acceptable short-term results.

Pathophysiology, Echocardiographic Diagnosis, and Treatment of Atrial Functional Mitral Regurgitation: JACC State-of-the-Art Review

The conventional view holds that functional mitral regurgitation (MR) is caused by restriction of leaflet motion resulting from displacement of the papillary muscle-bearing segments of the left ventricle. In the past decade, evidence has accrued suggesting functional MR can also be caused by left atrial enlargement. This underrecognized cause of secondary MR-atrial functional MR (AF-MR)-is mechanistically linked to annular enlargement, perturbations of annular contraction, and atriogenic leaflet tethering. AF-MR has been described in patients with atrial fibrillation and heart failure with preserved ejection fraction. Preliminary data suggest rhythm control may decrease MR severity in patients with atrial fibrillation. Additionally, several studies have reported reductions in MR and symptomatic improvement with restrictive annuloplasty and transcatheter edge-to-edge repair. This review discusses the pathophysiology, echocardiographic diagnosis, and treatment of AF-MR. AF-tricuspid regurgitation is also discussed.

Higher F-wave frequency associates with poor procedural success rate after Maze procedure

OBJECTIVES

Persistent atrial fibrillation (AF) causes atrial remodeling, which causes myocardial fibrosis and micro-reentry. Fibrosis may reduce wave voltage and micro-reentry may enhance the dominant frequency (DF) of the F-wave. We investigated whether the DF predicts procedural success by the Maze procedure.

METHODS

In 138 consecutive patients who underwent mitral valve surgery and a modified Cox-Maze III procedure for persistent AF in Nagoya University in 2002-2018, 96 (70%) were successfully cardioverted (group S); 42 had persistent or relapsed AF after surgery (group F). Patient data were compared between the groups. Cut-off values were determined by an ROC analysis and predictors of procedural success were evaluated. The DF was obtained from the F-wave of V1 by a high-speed Fourier analysis using the CEPAS software program.

RESULTS

Group F showed a significantly larger LA diameter, better LVEF, lower F-wave voltage, higher DF, and longer duration of AF. The cut-off values were as follows: LA diameter, 56 mm; EF, 64.5%; F-wave voltage, 0.13 mV; DF, 7.3 Hz; and duration of AF, 44 months. Each factor showed statistical significance in a univariate analysis; DF lost significance in the multivariate analysis. The higher (DF ≥ 7.3 Hz) and lower voltage group (≤ 0.13 mV) showed the worst procedural success rate (36%), while the lower DF (< 7.3 Hz) and higher voltage group (> 0.13 mV) showed a good rate (86%).

CONCLUSIONS

The DF of the F-wave is a useful predictor of procedural success after the Maze procedure in addition to the voltage of F-wave.

Size matters in atrial fibrillation: the underestimated importance of reduction of contiguous electrical mass underlying the effectiveness of catheter ablation

Evidence has accumulated over the last century of the importance of a critical electrical mass in sustaining atrial fibrillation (AF). AF ablation certainly reduces electrically contiguous atrial mass, but this is not widely accepted to be an important part of its mechanism of action. In this article, we review data showing that atrial size is correlated in many settings with AF propensity. Larger mammals are more likely to exhibit AF. This is seen both in the natural world and in animal models, where it is much easier to create a goat model than a mouse model of AF, for example. This also extends to humans-athletes, taller people, and obese individuals all have large atria and are more likely to exhibit AF. Within an individual, risk factors such as hypertension, valvular disease and ischaemia can enlarge the atrium and increase the risk of AF. With respect to AF ablation, we explore how variations in ablation strategy and the relative effectiveness of these strategies may suggest that a reduction in electrical atrial mass is an important mechanism of action. We counter this with examples in which there is no doubt that mass reduction is less important than competing theories such as ganglionated plexus ablation. We conclude that, when considering future strategies for the ablative therapy of AF, it is important not to discount the possibility that contiguous electrical mass reduction is the most important mechanism despite the disappointing consequence being that enhancing success rates in AF ablation may involve greater tissue destruction.

Novel risk score for predicting recurrence of atrial fibrillation after the Cryo-Maze procedure

OBJECTIVES

This study aimed to develop a novel risk score model for quantitative prediction of the rate of atrial fibrillation (AF) recurrence after the Cryo-Maze procedure in patients with persistent AF.

METHODS

We enrolled 450 consecutive patients who underwent the Cryo-Maze procedure for persistent AF concomitant with other cardiac procedures in our institute between 2001 and 2019. We randomly divided the cohort into two groups. We derived a model in a 'development cohort' (270 patients; 60%) and validated it in a 'test cohort' (180 patients; 40%) by receiver operating characteristic curve analysis.

RESULTS

The median follow-up was 5.2 (interquartile range: 2.0-9.9) years. The 1-, 5-, 10- and 15-year rates of freedom from AF recurrence in the entire cohort were 91.4%, 83.5%, 76.2% and 57.1%, respectively. Risk factors for AF recurrence examined by logistic regression analysis included F-wave voltage in V1 < 0.2 mV, preoperative AF duration >5 years and left atrial volume index >100 ml/m2. Points were assigned to each risk factor according to its odds ratio. A novel risk score model was developed using these three variables and age, with a range up to 10 points. High score (>7) predicted high rates of AF recurrence after the Cryo-Maze procedure. The area under the receiver operating characteristic curve of the novel risk model score was 0.78 (95% confidence interval: 0.65-0.91) in the test cohort.

CONCLUSIONS

Use of the Cryo-Maze procedure should be carefully considered in patients with a higher model score because of a higher risk of AF recurrence.

Simultaneous hybrid maze procedure for long-standing persistent atrial fibrillation with dilated atrium

Background

The efficacy of catheter-based or thoracoscopic ablation for treating long-standing persistent atrial fibrillation (AF) with a dilated atrium remains suboptimal. This study aimed to assess the feasibility and initial results of simultaneous hybrid ablation with a new biatrial lesion set in these patients.

Methods

Twenty-seven consecutive patients with long-standing persistent AF and dilated atrium underwent simultaneous hybrid ablation with a new biatrial lesion set consistent with the principle of the Cox maze procedure at our institution. Patients were followed up at 3, 6, and 12 months after the procedure and annually thereafter.

Results

After thoracoscopic epicardial ablation, endocardial mapping confirmed complete bilateral pulmonary vein isolation in 25 patients (96.2%). All patients were followed for a mean of 18.7 ± 8.9 months. Freedom from atrial tachyarrhythmia at 1 year after the single hybrid procedure was 64% with antiarrhythmic drugs and 60% without antiarrhythmic drugs. Freedom from atrial tachyarrhythmia at latest follow-up after the hybrid procedure and redo catheter ablation was 77.8% with antiarrhythmic drugs and 74.1% without antiarrhythmic drugs. In patients with sinus rhythm restoration, mean left atrial diameter decreased from 54.4 ± 4.3 mm to 45.2 ± 4.1 mm (P < .001), and mean right atrial diameter decreased from 59.4 ± 3.9 mm to 54.9 ± 4.4 mm (P < .001). Postoperative pleural effusion was observed in 3 patients (11.1%), and no adverse events occurred during follow-up.

Conclusions

In patients with long-standing persistent AF and a dilated atrium, simultaneous hybrid ablation with the new biatrial lesion set, in combination with touch-up catheter ablation when necessary, can achieve promising results. More studies are needed to confirm these findings.

Concomitant Left Atrial Reduction in Rheumatic Mitral Valve Disease With Giant Left Atrium: Our Technique With Midterm Results

OBJECTIVE

The giant left atrium is a frequent finding with rheumatic heart disease. The enlarged left atrium was found to be a risk factor for early mortality and postoperative higher thromboembolic events, but its management remains controversial. Most of the surgeons just do the mitral valve procedure without any intervention for enlarged left atrium. We present our center's experience of patients with giant left atrium who underwent a newer technique of left atrium reduction concomitant with mitral valve procedure.

METHODS

Between January 2012 and February 2015, 25 patients, who underwent surgery for concomitant left atrium reduction with mitral valve disease, were included in the study after institute's ethics committee clearance. Patients having combined aortic and mitral valve disease were excluded. Preoperative, intraoperative, and postoperative data were collected. All the patients were also followed up clinically and echocardiographically in postoperative period.

RESULTS

There were 15 (60%) females. The mean ± SD age of the patients was 36.92 ± 5.4 years. Preoperatively, all patients were in long-standing persistent atrial fibrillation. The mean ± SD bypass and aortic cross-clamp time were 74.56 ± 3.85 and 51.72 ± 4.32 minutes, respectively. There was a significant reduction of left atrium diameter and volume from 94.48 ± 11.0 mm to 40.08 ± 1.35 mm and 348.3 ± 121.1 to 26.57 ± 2.9 mL/m, respectively. There was no early or late mortality. At a mean ± SD follow-up of 42.28 ± 12.1 months, all patients were in New York Heart Association I or II class and 24 (96%) patients were in normal sinus rhythm.

CONCLUSIONS

Concurrent left atrium reduction with mitral valve procedure is a feasible and effective technique for event-free survival of the patients having giant left atrium with mitral disease.

Contact-Force Guided Pulmonary Vein Isolation does not Improve Success Rate in Persistent Atrial Fibrillation Patients and Severe Left Atrial Enlargement: A 12-month Follow-Up Study

Background

Catheter ablation is a cornerstone treatment strategy in atrial fibrillation (AF). Left atrial (LA) size is one of the contributors in development of AF recurrences. The impact of contact-forced (CF) guided catheter ablation on the success rate of persistent AF patients with severe enlarged LA has not been investigated yet.

Methods

Sixty-six patients with diagnosis of longstanding persistent AF undergoing catheter ablation were enrolled. All patients underwent a standard transthoracic echocardiography according to the guidelines. LA size was considered severely enlarged when LA diameter was ≥ 50 mm. CF catheter ablation with a Tacticath Quartz catheter (St Jude Medical, St. Paul, MN, USA) was used in all patients.

Results

The mean age was 61.9 ± 9.9 years, and LAD 47.8 ± 11.6 mm. Among 66 patients with persistent AF, 32 (48%) patients were diagnosed with AF recurrences. Twenty-eight (42%) patients had severely enlarged LA. The recurrence of AF was comparable in patients with and without severe enlarged LA (47% vs. 42%, p=0.79). The recurrence of AF was lower in patients who underwent CF-guided ablation with a normal LA dimension (36 %, p=0.54). Procedure duration was longer in patients with severely enlarged LA. LA dimension was not significantly different between patients with and without AF recurrence (49.8 ± 7.9 mm vs. 45.9 ± 7.5 mm, p=0.15). LAD and was significantly correlated with the time to recurrence of AF (r:-0.60, p=0.02).

Conclusion

Our preliminary findings have demonstrated that CF guided ablation does not improve the success rate in longstanding persistent AF patients with severe LA enlargement.

The long-term efficacy of concomitant maze IV surgery in patients with atrial fibrillation

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and associated with increased risk of morbidity and mortality. AF surgery is widely used for rhythm control of AF, but previous studies have shown varying results. This study sought to investigate the long-term efficacy of concomitant maze IV (CMIV) surgery in an unselected AF population and identify predictors of late AF recurrence.

Methods

In total 144 consecutive patients, who underwent CMIV between January 2006 and December 2010 were enrolled. By data from electronic medical records, registers, and rhythm prints, late AF recurrences and heart rhythm at latest follow-up were retrospectively registered. All patients still alive were invited to an ambulant follow-up to update rhythm status.

Results

During a median (IQR) follow-up of 7.39 (2.67) years, 114 (79.2%) patients had recurrence. The cumulative incidence of sinus rhythm (SR) without antiarrhythmic drugs (AADs) was 52.3% after 1 year. Long-term results after 2, 5 and 7 years were 47.9%, 32.6% and 25.1%, respectively. At latest follow-up 34.7% were in SR off AADs. No difference in 10-year event-free survival stratified by recurrence were found (p = 0.678). Contrary, time to death (5.40 vs. 3.43 years, p = 0.004) revealed death as competing risk event. The Fine-Gray model identified preoperative sustained AF (SAF) (SHR 3.54, 95%CI [2.35;5.32], p < 0.001), AF duration (1.08, [1.05;1.11], p < 0.001), and postoperative atrial tachyarrhythmia (ATA) (2.29, [1.21;4.35], p = 0.011) as predictors.

Conclusion

CMIV in the present cohort provided limited long-term success in obtaining SR. SAF, longer AF duration, and postoperative ATA were associated with late AF recurrence.

The Need for Consistent Predictors of Success for Surgical Ablation of Atrial Fibrillation

Objective

As with any medical therapy, identification of consistent and reliable outcome predictors is essential to understanding the efficacy of surgical ablation for atrial fibrillation. We originally intended to conduct a meta-analysis on atrial fibrillation surgical ablation to identify clinical factors that are most often associated with success. However, these studies are greatly heterogeneous. We conducted a systematic review to identify trends in outcome predictors and to provide recommendations for more uniform data analysis and reporting.

Methods

Relevant studies published between January 2005 and September 2013 were identified. To minimize heterogeneity, data were extracted only from multivariate analyses of outcome predictors. The initial approach for meta-analytic analyses was abandoned for a systematic review approach.

Results

From 604 initial citations, 19 studies with 5200 patients were included in the review. Systematic review of multivariable atrial fibrillation recurrence rates after surgical ablation revealed that studies were statistically heterogeneous, but atrial fibrillation recurrence after surgical ablation in mid-term follow-up was most often predicted by left atrium size, duration of atrial fibrillation, fine-wave atrial fibrillation, age of patient, and atrial fibrillation type.

Conclusions

The innate heterogeneity of published data precludes a meta-analysis for predictors of surgical ablation success. Of the few published studies that allow comparison, the most consistent predictors of failure were enlarged left atrium and long atrial fibrillation duration. These results underscore the need for consistent and reliable outcome predictors. We strongly recommend the development of a standardized system of measurement for consistent clinical parameters that can be used in outcome analyses for surgical ablation of atrial fibrillation.

Late Results of Cox Maze III Procedure in Patients with Atrial Fibrillation Associated with Structural Heart Disease

Background

Cox-Maze III procedure is one of the surgical techniques used in the surgical treatment of atrial fibrillation (AF).

Objectives

To determine late results of Cox-Maze III in terms of maintenance of sinus rhythm, and mortality and stroke rates.

Methods

Between January 2006 and January 2013, 93 patients were submitted to the cut-and-sew Cox-Maze III procedure in combination with structural heart disease repair. Heart rhythm was determined by 24-hour Holter monitoring. Procedural success rates were determined by longitudinal methods and recurrence predictors by multivariate Cox regression models.

Results

Thirteen patients that obtained hospital discharge alive were excluded due to lost follow-up. The remaining 80 patients were aged 49.9 ± 12 years and 47 (58.7%) of them were female. Involvement of mitral valve and rheumatic heart disease were found in 67 (83.7%) and 63 (78.7%) patients, respectively. Seventy patients (87.5%) had persistent or long-standing persistent AF. Mean follow-up with Holter monitoring was 27.5 months. There were no hospital deaths. Sinus rhythm maintenance rates were 88%, 85.1% and 80.6% at 6 months, 24 months and 36 months, respectively. Predictors of late recurrence of AF were female gender (HR 3.52; 95% CI 1.21-10.25; p = 0.02), coronary artery disease (HR 4.73 95% CI 1.37-16.36; p = 0.01) and greater left atrium diameter (HR 1.05; 95% CI 1.01-1.09; p = 0.02). Actuarial survival was 98.5% at 12, 24 and 48 months and actuarial freedom from stroke was 100%, 100% and 97.5% in the same time frames.

Conclusions

The Cox-Maze III procedure, in our experience, is efficacious for sinus rhythm maintenance, with very low late mortality and stroke rates.

The Prognostic Scoring System Establishment and Validation for Chronic Atrial Fibrillation Patients Receiving Modified Cox-Maze IV and Concomitant Cardiac Surgery

OBJECTIVES

Traditional Cox maze III is the gold standard for treatment of atrial fibrillation (AF). Because of its invasiveness, it has been replaced by a simplified procedure involving radiofrequency ablation of modified Cox maze IV. Although the modified Cox maze IV has the advantages of simplicity and less morbidity, a lower rate of sinus rhythm conversion has been reported. We try to establish a scoring system to predict the outcome of this procedure.

METHODS AND RESULTS

The derivation group consisted of 287 patients with structural heart disease and chronic AF who underwent cardiac surgery and modified Cox-maze IV procedure between August 2005 and March 2013. Demographics, clinical and laboratory variables were retrospectively collected as sinus conversional predictors. Overall sinus conversion rate was 75.8%. The parameters of the Soft Markers Scoring system included AF duration, preoperative left atrial (LA) size, rheumatic pathology and postoperative LA remodeling. We compared 80 patients from another hospital between January 2004 and December 2011 as a validation group to evaluate the power of the scoring system. Soft Markers Score indicated a good discriminative power by using the areas under the receiver operating characteristic curve (AUROC: 0.759 ± 0.032). The score was further divided into three groups: low (0-2), intermediate (3-5), and high (6-10), with predicted sinus conversion rates of 92.4%, 74.2%, and 47.8%, respectively.

CONCLUSIONS

In patients with chronic AF receiving modified Cox-maze IV procedure, the Soft Markers Score demonstrated good discriminative power of predicting sinus recovery in our patients and applied well to the other validation populations.

Radiofrequency ablation of atrial fibrillation during mitral valve surgery

Objectives

Atrial fibrillation is the most common form of arrhythmia in mitral valve disease. Radiofrequency ablation is most commonly used for atrial fibrillation ablation during mitral valve surgery.

Methods

This prospective study evaluated the midterm outcomes of intraoperative radiofrequency atrial fibrillation ablation during mitral valve surgery.

Results

52 patients were eligible for the study. Fifteen (28.8%) had a transseptal approach and 37 had a left atriotomy. Mitral valve replacement was performed in 16 patients, mitral valve repair in 31, and tricuspid repair in 8. Mean crossclamp time was 58.14. ± 20.08 min, and mean cardiopulmonary bypass time was 71.28 ± 20.31 min. The mean ablation time was 6.41 ± 0.21 min. There was no postoperative mortality. Sinus rhythm was documented in 44 (84.6%) patients on discharge, and 8 (15.4%) were discharged with atrial fibrillation; 2 of them returned to sinus rhythm after 3 months. After 12 months of follow-up, 46 (88.5%) patients were in sinus rhythm.

Conclusion

Left atrial monopolar radiofrequency ablation during mitral valve surgery is a safe procedure with a high success rate.

Guideline for the surgical treatment of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and its prevalence is ∼1-2% of the general population, but higher with increasing age and in patients with concomitant heart disease. The Cox-maze III procedure was a groundbreaking development and remains the surgical intervention with the highest cure rate, but due to its technical difficulty alternative techniques have been developed to create the lesions sets. The field is fast moving and there are now multiple energy sources, multiple potential lesion sets and even multiple guidelines addressing the issues surrounding the surgical treatment of AF both for patients undergoing this concomitantly with other cardiac surgical procedures and also as stand-alone procedures either via sternotomy or via videothoracoscopic techniques. The aim of this document is to bring together all major guidelines in this area into one resource for clinicians interested in surgery for AF. Where we felt that guidance was lacking, we also reviewed the evidence and provided summaries in those areas. We conclude that AF surgery is an effective intervention for patients with all types of AF undergoing concomitant cardiac surgery to reduce the incidence of AF, as demonstrated in multiple randomized studies. There is some evidence that this translates into reduced stroke risk, reduced heart failure risk and longer survival. In addition, symptomatic patients with AF may be considered for surgery after failed catheter intervention or even as an alternative to catheter intervention where either catheter ablation is contraindicated or by patient choice.

The Role of Echocardiography as a Predictor of the Incidence and Progression of Atrial Fibrillation

Atrial fibrillation is the most frequent sustained arrhythmia and is an independent risk factor for stroke and death. In recent years, major echocardiographic advances have been made with the development of new techniques and applications that can be extremely useful for the management of these patients. This paper describes the role of echocardiography as a predictor of the incidence and progression of atrial fibrillation. A detailed description of the most relevant studies and recognition of unresolved questions regarding this subject are presented here. A special emphasis will be given on new techniques that allow the assessment of myocardial deformation and their possible role in the way we treat these patients.

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.

Cardiac remodeling as a consequence of atrial fibrillation: An anatomical study of perfusion-fixed human heart specimens

Background

Atrial fibrillation (AF) causes a continuum of atrial anatomical remodeling.

Methods

Using a library of perfusion-fixed human hearts, specimens with AF were compared to controls. During this preliminary assessment study, direct measurements were taken of atrial volume, pulmonary vein (PV) circumference, and left atrial (LA) wall thicknesses.

Results

Hearts with AF typically had larger atrial volumes, as well as a much larger variation in volume compared to controls (range of 59.6–227.1 mL in AF hearts compared to 65.1–115.9 mL in controls). For all hearts, right PVs were larger than left PVs (mean: 171.4 ± 84.6 mm[2] for right and 118.2 ± 50.1 mm[2] for left, P < 0.005). LA wall thicknesses ranged from 0.7 mm to 3.1 mm for both AF and control hearts.

Conclusions

Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF. The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.