His-bundle Pacing vs. Right Ventricular Apical Pacing in Patients With Reduced Ejection Fraction

His-bundle Pacing vs. Right Ventricular Apical Pacing in Patients With Reduced Ejection

The study compares standard right ventricle apical pacing with so called His-bundle pacing, for patients with slightly or moderately reduced ejection fraction and atrioventricular block requiring pacemaker therapy. The primary outcome is left ventricular ejection fraction measured after 6 months.

Patients with reduced systolic ejection fraction (40≤ ejection fraction ≤55%) and pacemaker indication due to high degree AV block are included. The study has a randomized double blinded crossover design. Patients are implanted with a standard right ventricle lead and right atrial lead (if indicated), and in addition a His-bundle lead. Randomization is performed as to which pacing modality is used during the first 6 months. After 6 months the pacing modality is changed. Patients are blinded and endpoint adjudicators, including echocardiography staff, are blinded. Device nurse and physician are not blinded.

Primary endpoint is difference in left ventricular ejection fraction after 6 months, paired comparisons are used and each patient is their own control. Secondary endpoints include complications and safety of the device/electrode, and quality of life.

Inclusion Criteria:

• AV block II or III with high expected pacing need
• Left ventricular ejection fraction between 40% and 55% (inclusive)
• Willing to participate and sign informed consent

Exclusion Criteria:

• Under 18 years old
• Pregnant
• Hypertrophic cardiomyopathy
• Cardiac sarcoidosis
• Cardiac amyloidosis
• Previous myocardial infarction within last 3 months
• Ventricular septum defect or other other left ventricular corrective surgery
• Congenital heart disease surgically corrected
• Atrial fibrillation with uncontrolled rate (if not planned for AV node ablation)