Efficacy Study of Pacemakers to Treat Slow Heart Rate in Patients With Heart Failure

Inclusion Criteria

Age >18 years and able to provide informed consent to enroll in the trial, or consent through a legal guardian or power of attorney.
Previous clinical diagnosis of HF with current NYHA Class II-III symptoms
At least one of the following: Hospitalization for decompensated HF, Acute treatment for HF with intravenous loop diuretic or hemofiltration, Chronic treatment with a loop diuretic for control of HF symptoms + left atrial enlargement on echocardiography or E/e' ratio (≥14 average, ≥15 septal ) on echocardiography, Resting PCWP >15 mm Hg or LV end-diastolic pressure >18 mmHg at catheterization for dyspnea and/or exercise PCWP/LV end-diastolic pressure >25 mmHg, or Elevated NT-proBNP level (≥300 pg/ml )
Left ventricular EF ≥40% within 12 months with clinical stability
Stable cardiac medical therapy for ≥30 days
Sinus rhythm
Chronotropic incompetence on recent (within 6 months) clinical or screening exercise test, defined as heart rate reserve (HRR) <0.80 or <0.62 if on beta blockers
Meet both screening criteria on clinically-performed cardiopulmonary exercise testing within 12 months.

Exclusion Criteria

Inability to exercise, or non-cardiac condition that precludes exercise testing
Any contraindication to a pacemaker system
Non-cardiac condition limiting life expectancy to less than one year
Significant left sided structural valve disease (>mild stenosis, >moderate regurgitation)
Hypertrophic cardiomyopathy
Infiltrative or inflammatory myocardial disease (amyloid, sarcoid)
Pericardial disease
Non-group 2 pulmonary arterial hypertension
Chronic stable exertional angina
Acute coronary syndrome or revascularization within 60 days
Other clinically important causes of dyspnea
Atrial fibrillation
PR interval >210 msec
Resting heart rate (HR) > 100 bpm
A history of reduced ejection fraction (EF<40%)
Advanced chronic kidney disease (GFR < 20 ml/min/1.73m2 by modified MDRD equation)
Women of child bearing potential without negative pregnancy test and effective contraception
Severe anemia (Hemoglobin <10 g/dL)
Severe hepatic disease
Complex congenital heart disease
Listed for cardiac transplantation
Other class I indications for pacing