Study for the Treatment of Heart Failure With Preserved Ejection Fraction Associated With High Blood Pressure Using Right Atrial Pacing Controlled by the PressurePaceTM System

This study is a prospective, double blind, self-controlled, randomized, cross-over study to evaluate the feasibility, efficacy, and safety of treating patients with Heart Failure with preserved Ejection Fraction (HFpEF) associated with hypertension using the PressurePace™ system of Right Atrial Pacing regulated by blood pressure in subjects with dual chamber pacemakers. No surgery, intervention or implant will occur during this study. All subjects enrolled in the study already have a dual chamber pacemaker implanted for standard clinical indications. The objective of this study is to show that blood pressure-controlled right atrial pacing improves exercise tolerance, improves heart failure symptoms and improves hypertension control in subjects with HFpEF associated with hypertension compared to conventional bradycardia pacing alone. Each subject will have an office/clinic visit. Once the subject signs informed consent, the pacemaker will be interrogated by trained personnel. If all the inclusion/exclusion criteria are met, then the pacemaker will be connected to the pacemaker manufacturer's interrogation module which will be connected to the BaroPace interface. The system will run with clinical oversight in the office to determine suitability for outpatient function and subject usability. The system will then be used by the subjects for the duration of the study always with the direct supervision of a trained Clinical Research Coordinators. Subjects that met all inclusion and exclusion criteria will be entered into the baseline phase (Day 1 to Day 7) where subjects will continue to receive their baseline antihypertensive medications while on standard baseline pacing parameters. Subjects will have at baseline screening day and day 7, 24-hour Ambulatory BP monitoring (ABPM). On Screening Day subjects will undergo a 2 D echo to assess ejection fraction, 6-Minute Walk test and a treadmill using the Modified Bruce Protocol on screening and Day 7. On Day 7, if subject has \>3 lbs. weight loss, or \>10 mmHg drop in SBP or \>5 mmHg drop in DBP (mean of the past 3 12-hour BP readings at home) or is unable to tolerate at least 3 minutes on the Modified Bruce Protocol treadmill, or walk at least 225 meters during the 6-Minute Walk test, the subject will be discontinued from the study. Subjects that continue in the study will be randomized into two groups (8 subjects in each group), group 1 will use BaroPacing for the first 3 weeks (day 8 to day 28) and then switch to standard treatment for another 3 weeks (day 29 to day 49). Group 2 will use standard treatment for the first 3 weeks (day 8 to day 28) and then switch to BaroPacing for another 3 weeks (day 29 to day 49). Total study duration for a subject will be 7 weeks (49 +/- 5 days). At the end of 49 days, the subject will return to the office/clinic, the external system components will be disconnected, and the subject's pacemaker will be returned to pre-study parameters.