Recruiting

Cardiac Conditioning

Sponsor:

Denice Hodgson-Zingman, MD

Code:

NCT06332391

Conditions

Heart Failure, Systolic

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Exercise-similar cardiac pacing

Sham cardiac pacing

Study Details

Brief 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.

Conditions

Heart Failure, Systolic

Study ID

NCT06332391

Start date

Jun 26, 2024

Status verified date

Jun, 2026

Completion date

Nov 30, 2028

Anticipated

Primary completion date

Jun 30, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

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
  • Pregnancy
  • Implantable cardioverter defibrillator battery longevity < 1 year
  • Vulnerable populations such as prisoners and institutionalized individuals

Study Design

Enrollment

52 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Exercise-similar cardiac pacing

Atrial pacing to replicate exercise heart rate envelope once daily, 3 days per week, over 6 weeks while symptoms and vital signs are monitored and outcome measures assessed.

sham comparator: Sham cardiac pacing

Sham pacing to replicate exercise heart rate envelope once daily, 3 days per week, over 6 weeks while symptoms and vital signs are monitored and outcome measures assessed.

Interventions

Exercise-similar cardiac pacing

Cardiac pacing using subjects already-implanted cardioverter defibrillator to reproduced exercise heart rate envelope.

Sham cardiac pacing

Simulated (rates selected using programmer but not initiated) cardiac pacing using subjects already-implanted cardioverter defibrillator to reproduced exercise heart rate envelope.

Primary outcome measure

  • Change in left ventricular ejection fraction by echocardiogram [ Time Frame: at baseline versus 2 weeks, 4 weeks, 6 weeks from start of intervention/sham and at 3 months and 12 months after completion of intervention vs. sham. ]

Central Contacts and Locations

Central contacts

Denice Hodgson-Zingman, MD

+1 319 384 2915denice-zingman@uiowa.edu

Locations

University of Iowa Hospitals and Clinics

Recruiting

Iowa City, Iowa, United States, 52242

Contacts

Denice Hodgson-Zingman, MD

319-356-1616

Melissa Yoder, RN

319-384-1628melissa-yoder@uiowa.edu

Principal Investigator:

Denice Hodgson-Zingman, MD

More Information

Sponsor

Denice Hodgson-Zingman, MD

Last update posted

Jun 25, 2026

Last verified

Jun, 2026

Keywords

  • heart failure
  • exercise
  • heart rate
  • implantable defibrillator
  • cardiac conditioning
  • exercise tolerance
  • pacing
  • cardiac output
  • quality of life
  • walking distance

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Denice Hodgson-Zingman, MD on 2026-06-25.