New therapy tested in heart failure with preserved ejection fraction (HFpEF) patients with approved indications for pacing to determine if elevated pacing therapy is tolerated and whether there is a signal for efficacy.

Inclusion Criteria:

• Subject has had a market released dual chamber Medtronic Pacemaker with a Sleep function for at least 3 months
• Subject is stable on current medications
• Subject has dyspnea with exertion or diagnosed as New York Heart Association (NYHA) Class II or III Heart Failure
• Subject has had a prior Echo in past 6 months with: Ejection Fraction (EF) ≥ 50% and Diastolic volume <80 ml/m²
• Subject has evidence of hypertrophy (indexed to body surface area: men 115 g/m², women 95 g/m² or indexed to height: men 49.2 g/m2.7, women 46.7 g/m2.7) or Relative Wall thickness >0.42, or Wall Thickness>1.2cm (posterior wall)
• Subject is willing to sign and date the study Informed Consent Form (IC Form) - Subject is 18 years of age or older, or of legal age to give informed consent per local law
• Subject is expected to remain available for follow-up visits

Exclusion Criteria:

• Subject has permanent atrial fibrillation (AF) or AF noted on baseline interrogation rhythm strip
• Subject has uncontrolled BP; (systolic pressure needs to be >100 mmHg and <160 mmHg on medications)
• Subject has severe stenosis of the aortic or mitral valve, defined as valve area ≤1.0 cm² or severe regurgitation of the aortic or mitral valve
• Subject has symptomatic Chronic Obstructive Pulmonary Disease (COPD) requiring oxygen
• Subject's Pacemaker has less than 6 months of Pacemaker battery life
• Subject had an aortic valve replacement (surgical or TAVR) procedure less than 9 months prior to enrollment
• Subject's programmed upper rate limit is less than 100 bpm because of concerns of elevated pacing
• Subject is unable or unwilling to perform the 6 Minute Walk Test at all scheduled study visits
• Subject is currently enrolled or planning to enroll in a potentially confounding trial during the course of the study (co-enrollment in concurrent studies is only allowed when documented pre-approval is obtained from the Medtronic study manager)
• Subject is pregnant
• Subject meets any exclusion criteria required by local law
• Subject's life expectancy is less than 12 weeks
• Subject with medical condition that precludes the patient from participation in the opinion of the investigator
• Subject has known coronary disease with Class II angina

All enrolled subjects

Adverse events were collected for all patients from the time of enrollment through the time of study exit, which occurred 12 weeks after the baseline visit for subjects that did not exit early.

Definitions are consistent with clinicaltrials.gov definitions.

The study ended with fewer participants than was desired for the investigation. The study ended due to difficulty finding eligible patients.