NCT06332391 · Denice Hodgson-Zingman, MD
Paced Heart Rate Acceleration for Cardiac Conditioning
(HeartExcel)
What this study is about
A clinical trial of exercise-similar heart rate acceleration delivered via cardiac pacing vs. sham intervention in subjects at rest will be performed.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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 milliseconds
Exclusion criteria
- Age \< 18 years
- Inability to ambulate safely
- Congenital or primary valve disease
- Ongoing (not suppressed) atrial arrhythmias
- Left ventricular thrombus
- Severe peripheral arterial disease that limits mobility
- Hospital admission for life-threatening condition (e.g. heart failure, stroke) in the past 3 months
- Major surgery in the past 3 months or anticipated during the period of study
- Ventricular pacing indication in the absence of biventricular pacing
- Life expectancy \< 1 year
- Hemodialysis
- Hematocrit \< 30%
- Severe chronic lung disease that limits activity or requires oxygen
- Implantable cardioverter defibrillator battery longevity \< 1 year
- Vulnerable populations such as prisoners and institutionalized individuals
Where
- Iowa City, Iowa
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 25, 2026 · Source of record for eligibility and locations