Five-Year Outcomes of Concomitant Maze Procedure Using Nitrous Oxide vs Argon-Based Cryoablation

Area of Science:

• Cardiology
• Medical Devices
• Electrophysiology

Background:

• Cryoablation is a recognized method for myocardial ablation, preserving tissue structure.
• Limited comparative data exists for nitrous oxide (N2O)-based versus argon gas-based cryoprobes.

Purpose of the Study:

• To compare the long-term efficacy and safety of N2O-based and argon gas-based cryoprobes for myocardial ablation.
• To evaluate sinus rhythm maintenance and major adverse cardiovascular and cerebrovascular events (MACCEs) at 5-year follow-up.

Main Methods:

• A follow-up of a single-center, prospective, randomized controlled trial involving 60 patients.
• Patients were randomized into N2O or argon cryoprobe groups.
• Primary endpoint: sinus rhythm maintenance; Secondary endpoint: MACCEs (cardiac death, stroke, major bleeding, heart failure readmission).

Main Results:

• Comparable baseline and operative characteristics between N2O and argon groups.
• At 5-year follow-up, sinus rhythm maintenance was 81.8% (N2O) vs. 78.5% (argon) (P > .999).
• No significant difference in freedom from MACCEs (80.6% N2O vs. 81.9% argon; P = .978); significant reduction in left atrial volume index in both groups.

Conclusions:

• Both N2O and argon cryoprobes exhibit similar long-term efficacy in maintaining sinus rhythm.
• Comparable safety profiles were observed, with similar rates of MACCEs at 5-year follow-up.
• N2O and argon cryoprobes may offer similar efficacy and safety for arrested heart procedures long-term.