Personalized pacing for diastolic dysfunction and heart failure with preserved ejection fraction: Design and rationale for the PACE randomized controlled trial.

BACKGROUND

Patients with pacemakers and heart failure with preserved ejection fraction (HFpEF) or isolated diastolic dysfunction (DD) may benefit from a higher backup heart rate (HR) setting compared with the standard setting of 60 bpm.

OBJECTIVE

The purpose of this study was to assess the effects of a personalized backup HR setting (PACE group) compared with 60 bpm (control group).

METHODS

In this prospective, blinded, randomized controlled study, pacemaker patients with DD or HFpEF and atrial pacing with intrinsic ventricular conduction or conduction system or biventricular pacing are randomized to the PACE group or control group for 1 year. The primary outcome is the change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores. Secondary endpoints include changes in N-terminal pro-brain natriuretic peptide levels, physical and emotional MLHFQ subscores, and pacemaker-detected atrial arrhythmia burden, patient activity levels, and thoracic impedance; hospitalization for heart failure, atrial fibrillation, cerebrovascular accident, or myocardial infarction; and loop diuretic or antiarrhythmic medication initiation or up-titration. A sample size of 118 subjects is expected to allow detection of a 5-point change in MLHFQ score in an intention-to-treat analysis and allow initial assessment of clinical outcomes and subgroup analyses.

RESULTS

Enrollment began in July 2019. As of November 2020, 107 subjects have been enrolled. It is projected that the 1-year follow-up will be completed by December 2021.

CONCLUSION

Atrial pacing with intrinsic ventricular conduction or advanced ventricular pacing at a higher, personalized backup HR may be a therapeutic target for patients with isolated DD or HFpEF. The PACE trial is designed to test this hypothesis.