Incidence of and risk factors for pacemaker implantation after the modified Cryo-Maze procedure for atrial fibrillation

The impact of permanent pacemaker implantation on long-term survival after cardiac surgery: A systematic review and meta-analysis

OBJECTIVES

The long-term impact of permanent pacemaker (PPM) implantation on survival after cardiac surgery remains ill defined. We aimed to investigate the effect of PPM on survival and explore factors driving outcomes using meta-regression according to the type of surgery.

METHODS

MEDLINE, EMBASE, and the Cochrane Library Central Register of Controlled Trials were searched through October 2023 to identify studies reporting the long-term outcomes of PPM implantation. The primary outcome was all-cause mortality during follow-up. The secondary outcome was heart failure rehospitalization. The subgroup analysis and meta-regression analysis were performed according to the type of surgery.

RESULTS

A total of 28 studies met the inclusion criteria. 183,555 patients (n = 6298; PPM, n = 177,257; no PPM) were analyzed for all-cause mortality, with a weighted median follow-up of 79.7 months. PPM implantation was associated with increased risks of all-cause mortality during follow-up (hazard ratio, 1.22; confidence interval, 1.08-1.38, P < .01) and heart failure rehospitalization (hazard ratio, 1.24; confidence interval, 1.01-1.52, P = .04). Meta-regression demonstrated the adverse impact of PPM was less prominent in patients undergoing mitral or tricuspid valve surgery, whereas studies with a greater proportion with aortic valve replacement were associated with worse outcomes. Similarly, a greater proportion with atrioventricular block as an indication of PPM was associated with worse survival.

CONCLUSIONS

PPM implantation after cardiac surgery is associated with a greater risk of long-term all-cause mortality and heart failure rehospitalization. This impact is more prominent in patients undergoing aortic valve surgery or atrioventricular block as an indication than those undergoing mitral or tricuspid valve surgery.

Late Survival Benefits of Concomitant Surgical Ablation for Atrial Fibrillation During Cardiac Surgery: A Systematic Review and Meta-Analysis

The long-term survival benefits after surgical ablation for atrial fibrillation (AF) during cardiac surgery were not confirmed in previous randomized controlled trials or meta-analyses. This study aimed to investigate the long-term efficacy of surgical ablation in patients with AF. MEDLINE, EMBASE, and CENTRAL were searched to identify studies comparing concomitant surgical AF ablation with no surgical ablation during cardiac surgery. The primary outcome was long-term all-cause mortality. Secondary outcomes were stroke, heart failure rehospitalization, major bleeding, freedom from AF, and permanent pacemaker implantation during follow-up. To minimize confounding, only adjusted outcomes were used from observational studies. A total of 38 studies met the inclusion criteria. Of those, 9 randomized controlled trials and 15 observational studies with 41,678 patients (surgical ablation: n = 19,125; no surgical ablation: n = 22,553) were analyzed for all-cause mortality, with a weighted median follow-up of 62.0 months. Surgical ablation was associated with decreased risks of long-term mortality (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.71 to 0.84), stroke (HR 0.60, 95% CI 0.48 to 0.76), heart failure rehospitalization (HR 0.92, 95% CI 0.87 to 0.96), and more freedom from AF during follow-up (relative risk 1.93, 95% CI 1.50 to 2.49), whereas surgical ablation was associated with a higher risk of permanent pacemaker implantation during follow-up (HR 1.35, 95% CI 1.03 to 1.77). There was no significant difference in major bleeding during follow-up between the 2 groups. In patients with AF who underwent cardiac surgery, surgical ablation was associated with decreased risks of long-term mortality, stroke, and heart failure rehospitalization compared with patients with untreated AF. Given that the survival benefits were predominantly observed in observational studies, further randomized trials are necessary to confirm these findings.

Long-Term Outcome Following Concomitant Surgical Ablation for Atrial Fibrillation at University Hospital Basel: A Retrospective Study

Background and Objectives: This study aims to examine the success of concomitant surgical ablation in patients with atrial fibrillation after one, three, and five years. Additionally, important predictors for rhythm outcome and rates of permanent pacemaker implantations were analyzed. Materials and Methods: In this retrospective study, we included patients who were referred to the University Hospital of Basel, Switzerland, between 2011 and 2017. Primary outcome was one-year success of surgical ablation. Secondary outcomes include heart rhythm during entire follow-up, three- and five-years success, and need for additional arrhythmia interventions (incl. pacemaker implantation). Results: A total of 120 patients were analyzed and divided into two groups: pulmonary vein isolation (n = 55) and left atrial (n = 65). The median follow-up time was 4.4 years. Sinus rhythm was present in 66%, 64%, and 67% after one, three, and five years, respectively. When adjusted for preoperative type of atrial fibrillation, left atrial lesion set increased the chance of achieving sinus rhythm within 5 years by factor 6.5. The pacemaker-implantation rate was 22%, with significantly more pacemaker implantations in the left atrial group (9% vs. 32%, p = 0.0043). Conclusions: These real-world data demonstrate the high success rate of concomitant surgical ablation for atrial fibrillation. Our study highlights the importance of preoperative discussion in an interdisciplinary heart team to weigh the effectiveness of surgical ablation against the risk of a pacemaker implantation.

Optimal site of pacemaker lead implantation for persistent atrial standstill guided by electroanatomical mapping following a cox-maze procedure: a case report

Background

Atrial standstill is characterized by the absence of atrial activity. We report a case of a patient with extensive atrial fibrosis who underwent electrophysiologic study (EPS) and electroanatomical mapping (EAM) to identify surviving atrial sites amenable for pacemaker lead implantation.

Case summary

A 72-year-old man with persistent atrial fibrillation (AF) and atrial functional mitral regurgitation/tricuspid regurgitation (MR/TR) underwent a Cox-Maze surgery, mitral and tricuspid valve repair, and biatrial plication. He was referred because of post-operative presyncope symptoms. Electrocardiography revealed atrial standstill and junctional rhythm (JR); however, EAM revealed that both atria were almost entirely scarred and isolated fibrillation in left pulmonary veins and coronary sinus. Junctional rhythm retrogradely conducted around an atrioventricular (AV) node and pacing at this area could conduct to the ventricle through the AV node. An atrial pacing lead was implanted at this area, which yielded a QRS wave similar to the own beat. However, the atrial lead voltage was quite low; hence, ventricular pacing lead was implanted to avoid a future occurrence of pacing failure.

Discussion

This report demonstrates the benefits of EPS and EAM in informing optimal pacemaker implantation for patients with extensive scar in atrium.

The Society of Thoracic Surgeons 2023 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation

The Society of Thoracic Surgeons 2023 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation incorporate the most recent evidence for surgical ablation and left atrial appendage occlusion in different clinical scenarios. Substantial new evidence regarding the risks and benefits of surgical left atrial appendage occlusion and the long-term benefits of surgical ablation has been produced in the last 5 years. Compared with the 2017 clinical practice guideline, the current update has an emphasis on surgical ablation in first-time, nonemergent cardiac surgery and its long-term benefits, an extension of the recommendation to perform surgical ablation in all patients with atrial fibrillation undergoing first-time, nonemergent cardiac surgery, and a new class I recommendation for left atrial appendage occlusion in all patients with atrial fibrillation undergoing first-time, nonemergent cardiac surgery. Further guidance is provided for patients with structural heart disease and atrial fibrillation being considered for transcatheter valve repair or replacement, as well as patients in need of isolated left atrial appendage management who are not candidates for surgical ablation. The importance of a multidisciplinary team assessment, treatment planning, and long-term follow-up are reiterated in this clinical practice guideline with a class I recommendation, along with the other recommendations from the 2017 guidelines that remained unchanged in their class of recommendation and level of evidence.

Outcomes and residual gap analysis after the modified cryomaze procedure performed via right minithoracotomy versus sternotomy

Objectives

Developments in both technique and technology have enabled surgeons to perform the maze procedure via right minithoracotomy (RMT) to treat atrial fibrillation (AF). This study aimed to clarify the outcomes of the modified cryomaze procedure via the RMT approach compared with the sternotomy approach.

Methods

The study cohort comprised 803 consecutive patients who underwent a modified cryomaze procedure (130 via RMT and 673 via sternotomy) for paroxysmal AF and persistent AF from January 2001 to March 2022. The Gray test was applied to compare the incidence of recurrent atrial tachyarrhythmias. Additionally, residual electrical gaps were investigated in the patients who underwent additional catheter ablation for recurrent atrial tachyarrhythmias.

Results

The respective 1-, 2-, and 3-year cumulative incidences of recurrent atrial tachyarrhythmias were 13.1%, 19.5%, and 23.1% in the RMT group, and 9.3%, 10.9%, and 12.8% in the sternotomy group (Gray test P = .036). All 31 patients with recurrent atrial tachyarrhythmias underwent additional catheter ablation, comprising 14 (10.8%) in the RMT group and 17 (2.5%) in the sternotomy group. There was a significant intergroup difference in the site of residual electrical gaps; the RMT group more frequently had residual gaps in the tricuspid annulus than the sternotomy group (6.2% vs 0.4%; P < .001).

Conclusions

In the modified cryomaze procedure via the RMT approach, ablation failure is more likely to occur at the tricuspid annulus, where the surgical field of view is relatively poor compared with the sternotomy approach. Therefore, surgical ablation should be performed with caution when the RMT approach is used.