Improving haemodynamic optimization of cardiac resynchronization therapy for heart failure

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Devices

Background:

• Cardiac resynchronization therapy (CRT) optimization is crucial for patient outcomes.
• Non-invasive hemodynamic parameters are increasingly used for CRT optimization.
• Previous studies suggest high atrial paced heart rates improve optimization reliability.

Purpose of the Study:

• To determine if increased heart rate or atrial pacing itself is responsible for improved CRT optimization.
• To compare the reliability of hemodynamic optimization at rest, during slow atrial pacing, and fast atrial pacing.

Main Methods:

• Forty-three CRT patients underwent hemodynamic optimization of atrioventricular (AV) delay using beat-to-beat systolic blood pressure.
• Measurements were taken at rest (atrial-sensing), slow atrial pacing, and fast atrial pacing.
• A subset of 20 patients also underwent optimization during exercise.

Main Results:

• Intraclass correlation coefficients (ICCs) for optimization reliability were significantly higher during slow (0.45) and fast (0.52) atrial pacing compared to rest (0.20).
• Approximately 78% of the improvement in ICC from sinus rhythm to fast atrial pacing was achieved by pacing just above the sinus rate.
• Atrial pacing increased the signal (difference between best and worst AV delay) and reduced noise (SD of systolic blood pressure).

Conclusions:

• Atrial pacing, rather than solely an increased heart rate, is the primary driver for improved CRT optimization reliability.
• The enhancement in optimization is mainly due to an increased measured signal during atrial pacing.
• These findings support the use of atrial pacing for more robust non-invasive CRT optimization.