Comparison of Two Radiofrequency Ablation Devices for Atrial Fibrillation Concomitant With a Rheumatic Valve Procedure

Atrial fibrillation (AF)—a rapid, irregular heart rhythm that disrupts blood flow and raises stroke risk—often goes hand-in-hand with rheumatic heart valve disease. For patients needing valve surgery, adding a Cox Maze procedure (a surgical ablation to fix AF) can restore normal “sinus rhythm” (SR) and improve long-term health. But with two common radiofrequency (RF) ablation tools—non-irrigation forceps (AtriCure) and irrigation devices (Medtronic)—surgeons and patients alike wonder: Which works better?

A 2019 study from Chinese researchers sought to answer that question. Led by Qin Jiang of the Sichuan Provincial People’s Hospital and Sheng-Shou Hu of Fuwai Hospital (a top cardiovascular center), the team compared the two devices in 278 patients with rheumatic valve disease and permanent AF (AF lasting 12+ months without spontaneous recovery). Here’s what they found.

What the Study Examined

The retrospective study included adult patients treated between May 2013 and May 2017 who:

Had rheumatic valve disease (e.g., mitral/aortic valve damage) and a left atrium (LA) no larger than 70mm.
Needed valve replacement surgery plus RF ablation for AF.
Were excluded if they had active coronary artery disease (needing bypasses) or infective endocarditis.

Patients were split into two groups:

Group A (149 patients): Used AtriCure’s non-irrigation bipolar RF forceps (straight design, no saline cooling).
Group M (129 patients): Used Medtronic’s irrigation RF device (curved probe, saline cooling at 4–6mL/min, 25W power, 60°C tip temperature).

All procedures were done by senior surgeons via a median sternotomy (chest incision) with a heart-lung machine (cardiopulmonary bypass, CPB) and moderate hypothermia (28–32°C). The heart was stopped with a cold cardioplegia solution to protect it during surgery. If the LA was larger than 60mm, it was reduced in size.

Follow-up included:

24-hour Holter ECG monitoring at discharge, 6 months, and 12 months.
Routine checkups (history, physical exam, echocardiogram, blood tests).
Tracking of SR restoration (normal rhythm) and complications like stroke or pacemaker needs.

Key Results: Both Devices Work Equally Well

The study’s most important finding? There was no significant difference in how well the two devices restored sinus rhythm.

Ablation Time and LA Size

Ablation took ~29 minutes on average for both groups (28.9 ± 3.8 minutes for Group A vs. 29.5 ± 2.8 minutes for Group M). The time correlated with LA size: bigger LAs required longer ablation—a logical result, since enlarged atria have thicker walls that need more energy to create effective scar tissue.

Post-Operative Recovery

Inflammation (measured by the neutrophil-lymphocyte ratio, NLR) and heart injury (measured by troponin I, TnI) were similar between groups 12 hours after surgery. This means neither device caused more damage or inflammation—a critical safety check.

A few patients had temporary heart block (7 in Group A, 5 in Group M), which resolved with a temporary pacemaker or medication. Only 2 patients per group needed a permanent pacemaker—far below the 6–23% rate reported in other studies.

Sinus Rhythm Restoration

The goal of RF ablation is to stop AF and restore SR. For both groups, the success rates were nearly identical:

At discharge: 75.2% (Group A) vs. 73.6% (Group M).
6 months later: 72.5% vs. 71.3%.
12 months later: 70.5% vs. 69.8%.

None of these differences were statistically significant—meaning the devices performed equally well over time.

Why Both Devices Work Similarly

Bipolar RF ablation is popular because it creates transmural lesions—scar tissue that completely blocks abnormal electrical signals in the heart. For AF to stop, these lesions must be deep enough to reach through the atrial wall.

In healthy people, the LA wall between the pulmonary veins is 2–3mm thick. In patients with mitral valve disease (common in rheumatic heart disease), the LA can thicken to 5–6mm. Both devices deliver enough energy (70–80°C for ~1 minute) to create 3–6mm deep lesions—perfect for transmural blockage.

The study also noted that:

Surgeons were equally skilled with both devices, so no “learning curve” bias.
Inflammation (NLR) is linked to AF recurrence, but both groups had similar inflammation levels—explaining why SR rates stayed consistent.

Limitations and Future Directions

Like all studies, this one has caveats:

Retrospective design: Data was collected from past records, so there’s a risk of selection bias (e.g., surgeons might have chosen devices based on unrecorded factors).
AF recurrence tracking: The team used 24-hour Holter monitors, but longer monitoring (72 hours) might have caught more cases of AF.
No electrophysiological mapping: They couldn’t confirm if failed ablations were due to incomplete lesions or unaddressed AF mechanisms (like atrial fibrosis).

Future research should include:

Prospective trials: Randomly assigning patients to devices to eliminate bias.
Longer monitoring: 72-hour Holter or implantable monitors to better track AF recurrence.
Patient-specific factors: How age, LA fibrosis, or other conditions affect device performance.

What This Means for Patients and Surgeons

For patients with rheumatic valve disease and long-term AF who need valve surgery, this study is reassuring: both non-irrigation and irrigation RF ablation devices are equally effective at restoring sinus rhythm.

Surgeons can choose based on availability, cost, or personal preference—without worrying about one device being “better” than the other. The key takeaway? The skill of the surgeon and patient-specific factors (like LA size) matter more than the device itself.

The original study was published in the Chinese Medical Journal in 2019 by Qin Jiang, Sheng-Zhong Liu, Lu Jiang, Ke-Li Huang, Jing Guo, and Sheng-Shou Hu.

doi.org/10.1097/CM9.0000000000000276

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