Perioperative Considerations and Outcomes of the Hybrid Convergent Procedure for Atrial Fibrillation: A Prospective Observational Study

Technical Summary: Perioperative Considerations and Outcomes of the Hybrid Convergent Procedure for Atrial Fibrillation

Problem Statement
Atrial fibrillation (AF) represents a growing global health and economic burden, associated with increased morbidity and mortality. While traditional management focuses on rhythm or rate control, large studies have not consistently demonstrated a mortality benefit of rhythm control in heterogeneous populations. However, emerging evidence suggests that aggressive rhythm control, particularly in early AF, may prevent atrial remodeling and related complications such as stroke and heart failure. For patients with symptomatic paroxysmal or persistent AF refractory to class I/III anti-arrhythmic therapy, the hybrid convergent procedure has emerged as a therapeutic option. This two-stage approach combines a surgical thoracoscopic epicardial ablation with a subsequent endocardial catheter ablation. Despite its increasing utilization, there is a need to characterize the perioperative course, early complications, and rhythm outcomes to inform anesthetic and critical care management for this evolving patient population.

Methodology
This study was a prospective observational cohort study conducted at a single-center private hospital (Hollywood Private Hospital, Western Australia) over a two-year period (May 2019 to October 2021). The study received approval as a prospective clinical audit from the local Research Ethics Committee.

• Participants: The cohort included 62 patients with symptomatic paroxysmal or persistent AF refractory to anti-arrhythmic drugs. Exclusion criteria included prior cardiac surgery or indications for separate cardiac surgery. Perioperative data were available for 55 patients.
• Intervention: The surgical stage involved a subxiphoid incision to access the pericardial space via thoracoscope. An irrigated radiofrequency catheter was used to perform epicardial ablation of the posterior left atrial wall on the beating heart without cardiopulmonary bypass. A thoracoscopic left atrial appendage (LAA) occlusion was also performed. Pulmonary vein ablation was deferred to the second stage.
• Second Stage: Approximately six weeks to months later, patients underwent endocardial catheter ablation to complete pulmonary vein isolation and address any gaps in the posterior wall.
• Data Collection: Patients were admitted to the Intensive Care Unit (ICU) for a planned 24-hour stay. Data collected included demographics, baseline echocardiography, procedural details, analgesic requirements, daily troponin and BNP levels, complications, and rhythm monitoring. Rhythm status was assessed using implantable loop recorders (ILRs), cardiac implantable electronic devices, or Holter monitoring at 1, 3, and 12 months post-procedure.
• Statistical Analysis: Continuous variables were analyzed as mean ± standard deviation or median (interquartile range), and categorical variables as counts and percentages using Stata version 17.

Key Contributions
This study provides one of the first in-depth prospective analyses of the perioperative course of the hybrid convergent procedure. Its primary contributions include:

1. Perioperative Profile: Establishing a baseline for ICU length of stay, critical care support requirements, and pain management strategies specific to this procedure.
2. Biomarker Characterization: Documenting the expected trajectory of cardiac biomarkers (troponin and BNP) and ECG changes (ST elevation) post-epicardial ablation to distinguish expected inflammatory responses from ischemic complications.
3. Safety and Efficacy Data: Reporting early complication rates and 12-month rhythm outcomes, including freedom from atrial arrhythmia and AF burden reduction.

Results

• Demographics: The cohort was predominantly male (74.2%) with a mean age of 63.2 years. Most patients had persistent AF (56%) and a median of three prior ablations.
• Perioperative Course: The mean ICU length of stay was 25.2 ± 13.3 hours. Inotropic support was required in only 7.3% of patients, and no patients required postoperative mechanical ventilation. The mean hospital length of stay was 3.96 nights.
• Biomarkers and ECG: Troponin and BNP levels rose postoperatively, peaking on day 3 (mean troponin 884 ng/L; mean BNP 2665 ng/L). ST-segment elevation was observed in 32.7% of patients on day 2, most commonly across all leads.
• Complications: Major complications were uncommon. There were no deaths, strokes, cardiac tamponades, or phrenic nerve injuries. Pericarditis was the most common complication, occurring in 25.5% of patients. Two patients required ICU readmission (pneumonia and acute kidney injury/delirium).
• Rhythm Outcomes:
  • Early: Postoperative AF occurred in 23.7% of patients by day 3.
  • 12-Month: At 12 months, 62.9% of patients were free from atrial arrhythmia (on or off anti-arrhythmic drugs), and 58.1% were free from arrhythmia off anti-arrhythmic drugs.
  • Burden: 75.8% of patients had an AF burden of less than 5% at 12 months.
  • Long-term: At a median follow-up of 25 months, 51.6% of patients remained free from atrial arrhythmia.
• LAA Occlusion: Cardiac CT at 4 weeks confirmed 100% occlusion of the left atrial appendage in all patients.

Significance and Claims
The authors claim that the hybrid convergent procedure demonstrates a favorable perioperative profile characterized by short ICU stays, low rates of major complications, and limited need for advanced critical care support. The study highlights that while early postoperative arrhythmias and pericarditis are common, longer-term outcomes show meaningful reductions in AF burden.

The paper posits that these findings have important implications for the perioperative and critical care management of patients undergoing this procedure, particularly regarding the interpretation of postoperative biomarker elevations and ST-segment changes as expected inflammatory responses rather than ischemic events. The authors conclude that the procedure is a relatively safe option for patients with persistent AF who have failed prior ablation attempts, though they acknowledge limitations including the single-center design, small sample size, and the need for longer-term follow-up to fully assess durability and refine patient selection criteria.