Surgery for Lone Atrial Fibrillation: Present State-of-the-Art

Ten year experience with the concomitant Maze IV procedure for atrial fibrillation

OBJECTIVE

The Maze IV (M-IV) procedure is regarded as the golden standard in treatment for surgical ablation of atrial fibrillation (AF); however, long-term follow-up results are scarce. We present our institutional 10-year experience.

METHODS

We collected data of 117 consecutive patients who have undergone a concomitant M-IV procedure between April 2006 and April 2016. Primary endpoints are freedom of atrial arrhythmias and freedom of atrial arrhythmias off antiarrhythmic drugs (AAD).

RESULTS

Forty-seven patients (40.2%) had paroxysmal AF. Two-thirds of the procedures included mitral valve surgery. The average follow-up time per patient was 3.8 years (SD 2.8). Freedom of AF at 1 year was 79%, at 5 years freedom of AF was 69% and freedom of AF off AAD was 56%. Predictors of AF recurrence in multivariate analysis were age, preoperative pacemakers, redo cardiac surgery and in-hospital AF. Preoperative PVI ablation was found to be a protective factor.

CONCLUSIONS

The long-term outcomes of the M-IV procedure are good and remain stable over the years. Results could be improved if follow-up were to be intensified and recurrences dealt with aggressively. Key question: How many patients are free from AF in a 10-year period after concomitant M-IV surgical ablation? Key findings: In the long term around 70% of patients are free of AF with an increasing need for anti-arrhythmic drugs. Take home message: Early to midterm freedom from AF after concomitant M-IV procedure is high and remains stable after 3 years.

Risk factors and outcomes of intraoperative atrial fibrillation in patients undergoing thoracoscopic anatomic lung surgery

Background

Atrial fibrillation (AF) is common after thoracoscopic anatomic lung surgery and can be associated with increased adverse outcomes. However, the incidence, risk factors, and related outcomes of intraoperative AF in thoracoscopic anatomical lung surgery are unknown.

Methods

We retrospectively analyzed the files of 14,986 patients who had presented to the Shanghai Chest Hospital for thoracoscopic anatomic lung operations between January 2016 and December 2018. Univariate and multivariate analyses were conducted to identify risk factors for intraoperative AF, and a 1:1 propensity score-matched (PSM) analysis was performed to compare postoperative outcomes.

Results

The incidence of intraoperative AF was 1.2% (177/14,986). Multivariate analysis identified age older than or equal to 60 years [odds ratio (OR) =1.872, P<0.001], male sex (OR =2.979, P<0.001), diabetes mellitus (OR =2.287, P=0.014), lesion diameter of 1.4 cm or larger (OR =1.855, P=0.002), clinical nodal involvement (OR =1.920, P=0.005), lobectomy resection (OR =2.958, P=0.001), and right resection (OR =1.475, P=0.021) as independent risk factors for intraoperative AF. After 1:1 PSM, we evaluated outcomes in 350 (175 pairs) patients with or without intraoperative AF. Patients who had intraoperative AF were associated with prolonged median ICU stay {28 [26-54] vs. 24 [22-44] hours, P=0.001} and length of stay (LOS) {6 [4-7] vs. 5 [4-6] days, P=0.009}. However, the differences in cardiovascular, pulmonary, and other complications were not significant. In the subgroup analysis, patients who recovered sinus rhythm during operation (n=16) had a shorter median LOS {4 [4-6] vs. 6 [4-7] days, P=0.031}, and a similar incidence of complications compared with patients who recovered sinus rhythm after surgery (n=159).

Conclusions

We identified 7 independent risk factors for intraoperative AF, which were associated with prolonged ICU and hospital stays. The findings may help clinicians identify high-risk patients and take preventive measures to minimize the incidence and adverse outcomes of intraoperative AF.

European prospective multicentre study of hybrid thoracoscopic and transcatheter ablation of persistent atrial fibrillation: the HISTORIC-AF trial

OBJECTIVES

The HISTORIC-AF trial is a prospective, multicentre, single-arm study designed to evaluate the outcomes of a staged endoscopic and transcatheter ablation in patients with stand-alone, persistent or long-standing persistent atrial fibrillation (AF).

METHODS

From 2012 to 2015, 100 consecutive patients were enrolled and underwent thoracoscopic left atrial epicardial isolation ('box lesion') followed by transcatheter ablation in case of AF recurrency. The safety end point was the composite outcome of freedom from major adverse events at 30-days, while efficacy end points were: (i) primary: freedom from AF and stable sinus rhythm following isolated thoracospic ablation >60% and (ii) secondary: freedom from AF and stable sinus rhythm >80% following hybrid ablation (as per HRS criteria).

RESULTS

No death occurred and surgical thoracoscopic procedure was successfully completed in all patients. Survival free from major adverse events at 30 days was 94%: there were 3 permanent pacemaker implants, 2 episodes of stroke and 1 revision for bleeding. At discharge, 87% of patients were in sinus rhythm. A staged transcatheter ablation was carried out in all patients with AF recurrences at the end of 3 months blanking period (17% of patients). At 12-months follow-up, a stable restoration of sinus rhythm was achieved in 75% and 88% of patients following isolated thoracoscopic ablation and hybrid ablation, respectively.

CONCLUSIONS

The HISTORIC-AF trial showed that thoracoscopic isolated surgical ablation reached both the safety and the efficacy end points. Hybrid ablation steadily improved rhythm outcomes and may be considered in the future as the treatment of choice for patients with persistent and long-standing persistent AF.

ClinicalTrials.gov Identifier

NCT01622907.

Diagnosis and management of atrial fibrillation: an overview

Atrial fibrillation (AF) has been defined as the new cardiovascular "epidemic". Its prevalence is rising in developed countries, and the associated social and economic costs are high. In the last few years, there has been an increasing interest in understanding the mechanisms of AF and its management. New pharmacotherapies together with novel techniques for surgical and catheter treatment of AF have been developed, allowing the maintenance of sinus rhythm and the alleviation of symptoms in a large number of patients with AF. However, there are still some challenges that need to be addressed. This article gives an overview of the current state of the art on novel techniques for diagnosis and management of AF.

Hybrid Therapy for Atrial Fibrillation - Optimizing Treatment Strategies

Endocardial atrial fibrillation (AF) ablation techniques enable one to characterize the underlying substrate in order to tailor the ablation procedure but these ablation lesions are not always transmural nor long lasting. Surgical AF ablation techniques, on the other hand, create reliable linear lesions but the lesion set is based on empirical assumptions rather than specific patient characteristics. Performed in combination, both approaches seem to be complementary as they overcome their mutual shortcomings. Several hybrid or convergent ablation strategies with the use of various energy sources have been described. Medium and long term results are encouraging, especially in challenging settings such as persistent AF and failed endocardial catheter ablations.

Hybrid thoracoscopic and transvenous catheter ablation of atrial fibrillation

The hybrid approach combines an epicardial ablation with a percutaneous endocardial ablation in a single-step or sequential procedure. This study provides an overview of the hybrid procedure for the treatment of stand-alone atrial fibrillation (AF). Papers selected for this review were identified on PubMed and the final selection included nine studies. The total number of patients was 335 (range 15-101). Mean age ranged from 55.2 to 62.9 years. The hybrid approach achieved satisfactory results, with AF-antiarrhythmic drug-free success rates higher than those in isolated procedures. In particular, the bilateral approach with a bipolar device showed a high success rate independently of the AF type and seems to be the better choice for the hybrid procedure. Despite good preliminary results, large, multicentre trials of hybrid AF ablation that target a population of patients with long-standing persistent disease are necessary to establish whether this approach may represent, in the future, a gold-standard treatment for AF.

Hybrid approach for the treatment of long-standing persistent atrial fibrillation: electrophysiological findings and clinical results

OBJECTIVES

The sequential, staged hybrid approach has recently emerged as a novel strategy for the treatment of long-standing persistent atrial fibrillation (AF); nevertheless, the potential modifications in terms of electrophysiological findings and their correlation with mid-term results have not been fully elucidated so far.

METHODS

Forty-five patients with long-standing persistent AF underwent a hybrid procedure combining surgical closed-chest posterior left atrium (LA) and pulmonary veins (PV) isolation (box lesion) first, followed by transcatheter evaluation at least 1 month afterwards. Electrophysiological findings and their correlation with rhythm outcomes were assessed at different time points, i.e. following the surgical ablation (T1), during (T2) and at the end (T3) of the transcatheter evaluation and at 28-month follow-up (T4).

RESULTS

At T1, exit and entrance blocks were achieved in 100 and 91.1% (41 of 45) of patients, respectively. At T2, the percentage of conduction block was unchanged, while at T3 also entrance block was achieved in all instances. In terms of electrophysiological findings (at T2), PV reconnection occurred in 6.7% (3 of 45) of patients, fractionated electrograms were targeted in 44.4% (20 of 45) while right atrium isthmus lesion was performed in 24.4% (11 of 45) of patients. Sinus rhythm was restored in 75.6% (34 of 45) at T1, at T2 (with AF induction) in 68.9% (31 of 45), at T3 in 93.3% (42 of 45) and at T4 in 88.9% (40 of 45) of patients, respectively. In those patients with a bidirectional block at T1, sinus rhythm restoration steadily improved from 78 (32 of 41) at T1 to 82.9 (34 of 41) at T2 and finally 92.6% (38 of 41) at T4.

CONCLUSION

Complete posterior LA and PV isolation with the box lesion in a staged hybrid approach is associated with incremental benefits in terms of sinus rhythm maintenance in patients with long-standing persistent AF.

The hybrid approach for the surgical treatment of lone atrial fibrillation: one-year results employing a monopolar radiofrequency source

BACKGROUND

The hybrid technique combines a mono or bilateral epicardial approach with a percutaneous endocardial ablation in a single-step procedure. We present our early results with this technique employing a monopolar radiofrequency source through a right thoracoscopy in patients with lone atrial fibrillation (LAF).

METHODS

Between June 2009 and December 2010 nineteen consecutive patients (mean 60.8 ± 8.6 years, 84.2% male) underwent right unilateral minimally invasive hybrid procedure for LAF at our Institution. Ten patients (52.6.6%) had long-standing persistent AF while four (21.1%) had persistent and five (26.3%) paroxysmal AF. All patients were followed-up according the Heart Rhythm Society/European Heart Rhythm Association/European Cardiac Arrhythmia Society (HRS/EHRA/ECA) and Society of Thoracic Surgeon (STS) guidelines.

RESULTS

There were neither early nor late deaths. It was possible to complete all the procedures as planned without any conversion to cardiopulmonary bypass. No patient died during the follow up. At one year, 7/19 (36.8%) patients were in sinus rhythm with no episode of AF and off antiarrhythmic drugs (AAD). Time-related prevalence of postoperative AF peaked at 44.4% (41.3-47.4) at two weeks, was 30.4% (27.3-34.9) at three months, fell to 14.2% (11.6-18.1) by 6 months and was 13.3% (11.0-17.4) at 12 months Among patients with long-standing persistent (LSP) AF, 20% (2/10) were in Sinus rythm and off AAD. One-year success rates were 50% (2/4) in persistent and 60% (3/5) in paroxysmal AF. At 12 months estimated prevalence of antyarrhythmic drugs and Warfarin use were 26% (22.4-33.1) and 48% (37.2-53.2), respectively.

CONCLUSIONS

One year results combining the percutaneous endocardial with the right thoracoscopic epicardial technique were, in our experience, not satisfactory, particularly in patients with LSP and persistent AF. Our findings need to be confirmed by larger studies.

Treatment of lone atrial fibrillation: a look at the past, a view of the present and a glance at the future

Despite its proven efficacy, the Cox-Maze III procedure did not gain widespread acceptance for the treatment of lone atrial fibrillation (LAF) because of its complexity and technical difficulty. Surgical ablation for LAF can now be successfully performed utilizing minimally invasive techniques. This article provides an overview of the current state of the art in the surgical treatment of LAF. A brief review of pathophysiology, pharmacological treatment as well as catheter ablation is also provided. The most widely employed minimally invasive approach to LAF has been the video-assisted bilateral mini-thoracotomy or thoracoscopic pulmonary vein island creation and left atrial appendage removal or exclusion, usually with ganglionic plexi evaluation and destruction. Recently, a hybrid approach has been introduced, which combines a mono or bilateral epicardial approach with a percutaneous endocardial ablation in a single-step procedure to limit the shortcomings of both techniques. Suboptimal results of both catheter ablation and surgery suggest that success in the treatment of LAF will probably rely on a close collaboration between the surgeon and the electrophysiologist. Further studies are warranted to determine whether the hybrid approach is effective, especially in patients with long-standing persistent and persistent LAF.