Less is more: Can we achieve cardiac resynchronization with 2 leads only?

Area of Science:

• Cardiology
• Medical Devices
• Electrophysiology

Background:

• Cardiac Resynchronization Therapy (CRT) is a treatment for heart failure.
• Conventional CRT uses a three-lead Cardiac Resynchronization Therapy Defibrillator (3L CRTD).
• A new two-lead CRTD (DX CRTD) with a floating dipole for atrial signal detection has been developed.

Purpose of the Study:

• To compare the clinical and technical outcomes of the new DX CRTD with the conventional 3L CRTD.
• To evaluate the efficacy and safety of the DX CRTD system in heart failure patients.

Main Methods:

• A comparative study involving 37 patients implanted with either 3L CRTD (n=25) or DX CRTD (n=12).
• Clinical assessments included echocardiography, cardiopulmonary exercise tests, and heart failure status at 12 months follow-up.
• Device diagnostics were monitored for lead performance, sensing issues, and pacing parameters.

Main Results:

• No significant differences were observed in clinical outcomes, including NYHA class improvement, left ventricular reverse remodeling, and exercise tolerance between the two groups.
• The DX CRTD group showed a trend towards less far-field R-wave oversensing compared to the 3L CRTD group.
• Atrial undersensing did not occur in any patient, and no patient required atrial stimulation at 3-year follow-up.

Conclusions:

• Cardiac Resynchronization Therapy can be effectively delivered using a two-lead system (DX CRTD) in most patients.
• The DX CRTD is a viable alternative to the 3L CRTD, particularly when atrial pacing is not indicated.
• The DX CRTD system demonstrates comparable efficacy and potentially improved lead performance regarding oversensing.