A New Pacing Approach for Cardiac Conditioning and Enhanced Cardioprotection
Denice Hodgson-Zingman, MD
Summary
A clinical trial of exercise-similar heart rate acceleration delivered via cardiac pacing vs. sham intervention in subjects at rest will be performed. The study population comprises subjects with guideline-directed medically managed left ventricular dysfunction due to ischemic or non-ischemic cardiomyopathy and an existing implantable cardioverter defibrillator or biventricular implantable cardioverter defibrillator. The purpose of the study is to understand how the heart rate pattern of exercise contributes to the considerable cardiac conditioning effects of exercise and estimate whether the pacing approach may have translational clinical applicability. Fifty-two subjects will be randomized, single-blinded, to either the pacing intervention or a sham intervention which they will receive once daily, 3 days/week for 6 weeks. Baseline symptoms and clinical test results will be compared to the same measures at 2 weeks, 4 weeks and 6 weeks of intervention/sham and at 3 months and one-year post-intervention. The primary endpoint will be the change in left ventricular ejection fraction from baseline in intervention vs. sham groups (mixed effects linear regression with time and treatment arm as fixed effects and pre-specified covariates of sex and cardiomyopathy type as random effects). Secondary endpoints will include changes in quality of life, 6-minute walk distance, cardiopulmonary exercise test (CPET) measures, daily activity and major adverse cardiac events (MACE) at 3 and 12 months between pacing and sham groups. A "dose-response" analysis of outcomes at 2, 4, and 6 weeks of the intervention vs. sham compared with baseline will be performed.
Description
Subjects and protocol: This is a phase II randomized, controlled, prospective clinical trial in subjects with systolic heart failure. It is designed to assess the effect on symptoms, functional, structural, and medical outcomes in response to an atrial paced reproduction of the heart rate exercise pattern delivered regularly over a 6-week period. A single center (University of Iowa) will execute the intervention/sham and subject testing. A separate center (Cleveland Clinic) will perform statistical analysis of deidentified data. Fifty-two subjects will be randomized 1:1 by computer generated c…
Eligibility
- Age range
- 18–120 years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria: * Provision of signed and dated informed consent form * Stated willingness to comply with all study procedures and availability for the duration of the study * Male or female sex * Age 18 years or greater * Available transportation for study visits * Left ventricular ejection fraction \< or = 40% despite at least 3 months guideline-directed medial therapy * NYHA class II-III heart failure symptoms * Atrial-lead inclusive implantable cardioverter defibrillator or biventricular defibrillator in place \> 3 months * Intrinsic or biventricular paced QRS duration of \<= 120 mill…
Interventions
- DeviceExercise-similar cardiac pacing
Cardiac pacing using subjects already-implanted cardioverter defibrillator to reproduced exercise heart rate envelope.
- DeviceSham cardiac pacing
Simulated (rates selected using programmer but not initiated) cardiac pacing using subjects already-implanted cardioverter defibrillator to reproduced exercise heart rate envelope.
Location
- University of Iowa Hospitals and ClinicsIowa City, Iowa