Randomized controlled trial comparing simultaneous versus optimized sequential interventricular stimulation during...

Area of Science:

• Cardiology
• Medical Devices
• Heart Failure Management

Background:

• Cardiac resynchronization therapy (CRT) is established for heart failure (HF) with ventricular dyssynchrony.
• This study investigates optimizing the interventricular stimulating interval (V-V) versus simultaneous stimulation during CRT.

Purpose of the Study:

• To evaluate if optimizing V-V interval for sequential ventricular activation improves clinical outcomes compared to simultaneous V-V stimulation in CRT patients.
• To demonstrate noninferiority of optimized V-V timing using a composite clinical endpoint.

Main Methods:

• A randomized, double-blind, controlled study in NYHA class III/IV HF patients indicated for CRT and ICD.
• Patients received either simultaneous CRT or CRT with optimized V-V settings for 6 months.
• Echocardiography guided AV delay optimization and V-V optimization to minimize septal-to-posterior wall motion delay.

Main Results:

• The composite clinical endpoint improved in 75.4% of optimized patients versus 64.7% of simultaneous patients (P < .001 for noninferiority).
• Superiority was demonstrated with more optimized patients showing improvement (P = .03).
• NYHA functional class improved significantly more in the optimized group (75.0% vs 58.0%, P = .01).

Conclusions:

• Optimized sequential V-V stimulation during CRT offers modest clinical benefit in NYHA class III/IV HF patients.
• Optimizing V-V timing can be a valuable tool to increase the proportion of patients responding to CRT.