Late results of the Cox-maze IV procedure in patients undergoing coronary artery bypass grafting

Surgical Coronary Revascularization in Patients With Underlying Atrial Fibrillation: State-of-the-Art Review

The number of individuals referred for coronary artery bypass grafting (CABG) with preoperative atrial fibrillation (AF) is reported to be 8% to 20%. Atrial fibrillation is a known marker of high-risk patients as it was repeatedly found to negatively influence survival. Therefore, when performing surgical revascularization, consideration should be given to the concomitant treatment of the arrhythmia, the clinical consequences of the arrhythmia itself, and the selection of adequate surgical techniques. This state-of-the-art review aimed to provide a comprehensive analysis of the current understanding of, advancements in, and optimal strategies for CABG in patients with underlying AF. The following topics are considered: stroke prevention, prophylaxis and occurrence of postoperative AF, the role of surgical ablation and left atrial appendage occlusion, and an on-pump vs off-pump strategy. Multiple acute complications can occur in patients with preexisting AF undergoing CABG, each of which can have a significant effect on patient outcomes. Long-term results in these patients and the future perspectives of this scientific area were also addressed. Preoperative arrhythmia should always be considered for surgical ablation because such an approach improves prognosis without increasing perioperative risk. While planning a revascularization strategy, it should be noted that although off-pump coronary artery bypass provides better short-term outcomes, conventional on-pump approach may be beneficial at long-term follow-up. By collecting the current evidence, addressing knowledge gaps, and offering practical recommendations, this state-of-the-art review serves as a valuable resource for clinicians involved in the management of patients with AF undergoing CABG, ultimately contributing to improved outcomes and enhanced patient care.

Concomitant Treatment of Atrial Fibrillation in Isolated Coronary Artery Bypass Grafting

BACKGROUND

Societal guidelines support concomitant management of atrial fibrillation (AF) in patients undergoing cardiac surgery. To assess real-world adoption and outcomes, this study evaluated Medicare beneficiaries with AF who underwent isolated coronary artery bypass grafting (CABG) with surgical ablation (SA) or left atrial appendage obliteration (LAAO) or both procedures in combination (SA + LAAO).

METHODS

The US Centers for Medicare & Medicaid Services inpatient claims database identified all patients with AF who underwent isolated CABG from 2018 to 2020. Diagnosis-related group and International Classification of Diseases-10th revision procedure codes defined covariates for doubly robust risk adjustment.

RESULTS

A total of 19,524 patients with preoperative AF who underwent isolated CABG were stratified by SA + LAAO (3475 patients; 17.8%), LAAO only (4541 patients; 23.3%), or no AF treatment (11,508 patients; 58.9%). After doubly robust risk adjustment, longitudinal analysis highlighted that concomitant AF treatment with SA + LAAO (hazard ratio [HR], 0.74; P = .049) or LAAO alone (HR, 0.75; P = . 031) was associated with a significant reduction in readmission for stroke at 3 years compared with no AF treatment. Furthermore, SA + LAAO (HR, 0.86; P = .016) but not LAAO alone (HR, 0.97; P = .573) was associated with improved survival compared with no AF treatment. Finally, SA + LAAO was associated with a superior composite outcome of freedom from stroke or death at 3 years compared with LAAO alone (HR, 0.86;, P = .033) or no AF treatment (HR, 0.81; P = .001).

CONCLUSIONS

In Medicare beneficiaries with AF who underwent isolated CABG, concomitant AF treatment was associated with reduced 3-year readmission for stroke. SA + LAAO was associated with superior reduction in stroke or death at 3 years compared with LAAO alone or no AF treatment.

Atrial fibrillation ablation improves late survival after concomitant cardiac surgery

OBJECTIVE

Preoperative atrial fibrillation (AF) increases risk of stroke, heart failure, and all-cause mortality after cardiac surgery. Despite encouraging results and guideline recommendations, surgical ablation (SA) for AF concomitant with other heart surgery remains low. In the current study we aimed to address the long-term mortality after SA concomitant with cardiac surgery.

METHODS

This report pertains to the HEart surgery In atrial fibrillation and Supraventricular Tachycardia (HEIST) registry. We identified 20,765 adult patients (62% male) with preoperative AF who underwent conventional sternotomy heart surgery between 2010 and 2021 in 8 tertiary centers in Poland, Netherlands, and Italy. We used Cox proportional hazards models for computations and propensity score matching to minimize differences in baseline characteristics.

RESULTS

Of included patients, 2755 (13.4%) underwent SA for AF. The highest rates of SA were observed for mitral interventions (mitral valve repair or replacement and tricuspid intervention, 25.2%), lowest for isolated coronary artery bypass grafting (6.2%). Patients in the SA group were younger (mean age 64.5 ± 9.0 years vs 68.7 ± 16.0 years; P < .001) and lower risk (mean European System for Cardiac Operative Risk Evaluation [EuroSCORE] II, 4.1 vs 5.7; P < .001). During the 11-year study period, there was a mortality reduction associated with SA (hazard ratio, 0.57; 95% CI, 0.52-0.62; P < .001). After propensity matching, 2750 pairs with similar baseline characteristics were identified. SA was associated with 16% mortality decline (hazard ratio, 0.84; 95% CI, 0.75-0.94; P = .003).

CONCLUSIONS

In this multicenter, retrospective, propensity matched study, SA concomitant with other cardiac surgery was associated with improved long-term survival regardless of baseline surgical risk.

Mid‐term outcomes of concomitant Cox‐Maze IV: Results from a multicenter prospective registry

Background

Benefits of concomitant atrial fibrillation (AF) surgical treatment are well established. Cardiac societies support treating AF during cardiac surgery with a class I recommendation. Despite these guidelines, adoption has been inconsistent. We report results of routine performance of concomitant Cox‐Maze IV (CMIV) from participating centers using a standardized, prospective registry.

Methods

Nine surgeons at four cardiac surgery programs enrolled 807 patients undergoing concomitant CMIV surgery over 12 years. Lesions were created using bipolar radiofrequency clamps and cryoablation probes. Follow‐up occurred at 3‐ and 6‐months, then annually for 3 years. Freedom from AF was defined as no episode >30 s of atrial arrhythmia.

Results

Sixty‐four percent of patients were male, mean age 69 years, mean left atrial size 4.6 cm, mean preoperative AF duration 4.0 years, mean EuroSCORE 6.4, and mean CHADS₂ score 3.1. Thirty‐day postoperative mortality and neurologic event rates were 3.3% and 1.3%, respectively. New pacemaker implant rate was 6.3%. Freedom from AF rates at 1‐ and 3‐years stratified by preoperative AF type were: paroxysmal 94.6% and 87.5%, persistent 82.1% and 81.9%, and longstanding persistent 84.1% and 78.1%. At 3‐year follow up, 84% of patients were off antiarrhythmic drugs and 74% of sinus rhythm patients were off oral anticoagulants.

Conclusions

Routine CMIV is safe and effective. Acceptable outcomes can be achieved across multiple centers and multiple operators even in a moderate risk patient population undergoing more complex procedures. Surgeons and institutions should be encouraged by all cardiac societies to adopt the CMIV procedure to maximize patient benefit.

The long-term outcomes and durability of the Cox-Maze IV procedure for atrial fibrillation

OBJECTIVE

Surgical ablation of atrial fibrillation (AF) is indicated both in patients with AF undergoing concomitant cardiac surgery and in those who have not responded to medical and/or catheter-based ablation therapy. This study examined our long-term outcomes following the Cox-Maze IV procedure (CMP-IV).

METHODS

Between May 2003 and March 2018, 853 patients underwent either biatrial CMP-IV (n = 765) or a left-sided CMP-IV (n = 88) lesion set with complete isolation of the posterior left atrium. Freedom from atrial tachyarrhythmia (ATA) was assessed for up to 10 years. Rhythm outcomes were compared in multiple subgroups. Predictors of recurrence were determined using Fine-Gray regression, allowing for death as the competing risk.

RESULTS

The majority of patients (513/853, 60%) had nonparoxysmal AF. Twenty-four percent of patients (201/853) had not responded to at least 1 catheter-based ablation. Prolonged monitoring was used in 76% (647/853) of patients during their follow-up. Freedom from ATA was 92% (552/598), 84% (213/253), and 77% (67/87) at 1, 5, and 10 years, respectively. By competing risk analysis, incidence of first ATA recurrence was 11%, 23%, and 35% at 1, 5, and 10 years, respectively. On Fine-Gray regression, age, peripheral vascular disease, nonparoxysmal AF, left atrial size, early postoperative ATAs, and absence of sinus rhythm at discharge were the predictors of first ATA recurrence over 10 years of follow-up.

CONCLUSIONS

The CMP-IV had an excellent long-term efficacy at maintaining sinus rhythm. At late follow-up, the results of the CMP-IV remained superior to those reported for catheter ablation and other forms of surgical ablation for AF. Age, left atrial size, and nonparoxysmal AF were the most relevant predictors of late recurrence.

Atrial fibrillation in patients with coronary heart disease: current state of the problem

Atrial fibrillation is one of the most common types of cardiac arrhythmia observed in clinical practice. Despite advances in the diagnosis and treatment, atrial fibrillation remains one of the leading causes of cardiovascular mortality and morbidity. In addition, atrial fibrillation is quite often combined with other pathologies of the cardiovascular system and is a marker of an unfavorable outcome. Several previous studies have demonstrated reduced survival in patients with coronary artery disease and atrial fibrillation who have not undergone surgery for arrhythmia. According to other data, the presence of preoperative atrial fibrillation among patients undergoing isolated coronary artery bypass grafting was associated with significantly higher rates of major postoperative complications. Nowadays, no one doubts the fact that atrial fibrillation during a coronary artery bypass surgery is a risk factor for increased hospital mortality, postoperative morbidity and leads to a decrease in the long-term survival. The studies confirm the necessity of surgical ablation for atrial fibrillation during coronary revascularization to reduce both short-term and long-term postoperative mortality and late complications.

Is pulmonary vein isolation enough for persistent atrial fibrillation?

Pulmonary vein isolation (PVI) is a well-established treatment for atrial fibrillation (AF); however, studies report suboptimal outcomes in persistent AF. Adjuvant ablation targeting the substrate outside the pulmonary veins has been proposed to improve the success rates of the procedure. In this review, we summarize the current evidence regarding additional ablation over PVI in persistent AF. We describe the different approaches for adjuvant ablation, outcomes, and future perspectives.

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

INTRODUCTION

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Management of Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting: Review of the Literature

Untreated atrial fibrillation is associated with an increased risk of all-cause mortality and morbidity. Despite the current guidelines recommending surgical ablation of atrial fibrillation at the time of coronary artery bypass surgery, most patients with concomitant atrial fibrillation and coronary artery disease do not receive surgical ablation for their atrial fibrillation. This review reports the efficacy of different surgical ablation techniques used for the treatment of atrial fibrillation during coronary artery bypass. PubMed was systematically searched for studies reporting outcomes of concomitant surgical ablation in coronary artery bypass patients between January 2002 and March 2018. Data were independently extracted and analyzed by two investigators. Twenty-four studies were included. Twelve studies exclusively reported outcomes of surgical ablation in patients undergoing coronary artery bypass, whereas the remaining 12 reported outcomes of concomitant cardiac surgery with subgroup analysis. Only four studies performed the concomitant Cox-Maze procedure. Freedom from atrial tachyarrhythmia was reported as high as 98% at 1 year and 76% at 5 years with Cox-Maze procedure, whereas lesser lesion sets had more variable outcomes, ranging from 35% to 93%. In most studies, the addition of surgical ablation was not associated with increased morbidity and mortality. Although the Cox-Maze procedure had the greatest short- and long-term success rates, most studies comprising the evidence documenting the safety and efficacy of adding surgical ablation were of low or moderate quality. There was a great deal of heterogeneity among study populations, follow-up times, methods, and definition of failure. To establish a consensus regarding a surgical ablation technique for atrial fibrillation in coronary artery bypass population, larger multicenter randomized controlled studies need to be designed.

Concomitant surgical atrial fibrillation ablation is safe and efficacious in patients undergoing double valve replacement - A cohort study

BACKGROUND

Current European Society of Cardiology Guidelines recommend concomitant atrial fibrillation (AF) ablation for all symptomatic patients undergoing other cardiac surgeries, but the safety and potential benefits of concomitant atrial fibrillation (AF) ablation at the time of double valve replacement (DVR: aortic and mitral valve replacement) remains unexamined.

MATERIALS AND METHODS

We conducted a retrospective review of 238 patients with AF who underwent DVR with or without concomitant surgical ablation (Ablation group, n = 113; Non-ablation group, n = 125) at a single institute from April 2006 to September 2011.

RESULTS

There were no significant group differences in early postoperative mortality and morbidity, late survival, and freedom from major cardiac and cerebrovascular events (MACCEs). However, the Ablation group exhibited higher rates of sinus rhythm restoration at discharge (86.7% vs. 5.6%, P < 0.01) and at last follow-up (71.2% vs. 8.5%, P < 0.01). Follow-up echocardiography demonstrated smaller left atrial dimension and higher ejection fraction in the Ablation group (both P < 0.01).

CONCLUSION

Concomitant surgical ablation for AF did not increase perioperative mortality or morbidity in patients undergoing DVR, but significantly increased sinus rhythm restoration, improved heart function, and decreased oral anticoagulation requirements.

The Cox-maze IV procedure in its second decade: still the gold standard?

Atrial fibrillation (AF) is the most common cardiac arrhythmia and the treatment options include medical treatment and catheter-based or surgical interventions. AF is a major cause of stroke, and its prevalence is increasing. The surgical treatment of AF has been revolutionized over the past 2 decades through surgical innovation and improvements in endoscopic imaging, ablation technology and surgical instrumentation. The Cox-maze (CM) procedure, which was developed by James Cox and introduced clinically in 1987, is a procedure in which multiple incisions are created in both the left and the right atria to eliminate AF while allowing the sinus impulse to reach the atrioventricular node. This procedure became the gold standard for the surgical treatment of AF. Its latest iteration is termed the CM IV and was introduced in 2002. The CM IV replaced the previous cut-and-sew method (CM III) by replacing most of the incisions with a combination of bipolar radiofrequency and cryoablation. The use of ablation technologies, made the CM IV technically easier, faster and more amenable to minimally invasive approaches. The aims of this article are to review the indications and preoperative planning for the CM IV, to describe the operative technique and to review the literature including comparisons of the CM IV with the previous cut-and-sew method. Finally, this review explores future directions for the surgical treatment of patients with AF.