Impact of Optimized Pacing Strategies on Clinical and Hemodynamic Outcomes in Heart Failure Patients With Pacemaker (OPTPACE-HF)

April 28, 2026 updated by: Juwon Kim, Samsung Medical Center

Clinical and Hemodynamic Outcomes of OPTimized PACing StratEgies in Heart Failure Patients With Pacing Indications: Randomized-Controlled Trial (OPTPACE-HF)

This study aims to evaluate the clinical impact of an optimized pacing strategy in patients with heart failure.

  • Intervention: Adjustment of the pacemaker lower rate limit to an individualized, hemodynamically optimized heart rate.
  • Primary Endpoint: Heart failure symptoms, assessed by the Kansas City Cardiomyopathy Questionnaire score.
  • Hypothesis: In patients with heart failure requiring permanent pacing, an optimized pacing strategy will lead to a significant improvement in heart failure symptoms (Kansas City Cardiomyopathy Questionnaire score) at 12 months compared with the conventional pacing strategy.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Heart failure is a growing health concern with increasing prevalence in the aging population, and permanent pacemaker implantation is frequently required due to concomitant bradyarrhythmias. Heart rate is closely associated with hemodynamic status in patients with heart failure; however, evidence guiding the optimal pacemaker lower rate setting remains limited. Although the conventional lower rate is typically set at 50-60 bpm, recent studies suggest that a moderately increased pacing rate may improve hemodynamics and clinical outcomes. Furthermore, advances in physiological pacing techniques, such as conduction system pacing, provide the potential for greater clinical benefits through optimized heart rate settings in this patient population.

Enrolled subjects are randomized in a 1:1 ratio into either the optimized pacing group or the conventional pacing strategy group based on stratification factors.

The optimized pacing group undergoes post-procedural right heart catheterization with adjustments to the lower rate limit, where the heart rate (HR) that yields the lowest mean pulmonary capillary wedge pressure (mPCWP) or the highest cardiac output is determined as the optimal HR. In the conventional pacing strategy group, the lower rate limit is set at 60 bpm. Clinical symptoms and parameters of both groups are subsequently compared over a one-year follow-up period.

Study Type

Interventional

Enrollment (Estimated)

106

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • South Korea
    • Seoul
      • Seoul, Seoul, South Korea, 06351
        • Recruiting
        • Samsung Medical Center
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with symptomatic bradycardia who meet the indication for permanent pacemaker implantation and fulfill one of the following conditions:

    1. Sick sinus syndrome with or without impaired atrioventricular conduction
    2. Persistent or permanent atrial fibrillation with slow ventricular response
    3. Chronotropic incompetence
  • Patients diagnosed with heart failure with left ventricular ejection fraction ≥ 50% on transthoracic echocardiography with at least one of the following:
  • H2FPEF score ≥ 6 or HFA-PEFF score ≥ 5
  • N-terminal pro-B-type natriuretic peptide ≥ 300 pg/mL (sinus rhythm) or ≥ 600 pg/mL (atrial fibrillation)
  • Prior hospitalization for heart failure or documented use of loop diuretics for heart failure symptoms

Exclusion Criteria:

  • Patients expected to have a ventricular pacing burden ≥ 20% without sufficient capture of cardiac physiologic pacing, which includes biventricular pacing, His bundle pacing, and left bundle branch area pacing.

(Sufficient cardiac physiologic pacing is defined as a paced QRS duration ≤ 140 ms.)

  • Patients not expected to achieve sufficient pacing dependency, defined as:

    1. In sinus rhythm: baseline atrial rate > 60 bpm on Holter monitoring or inpatient ECG monitoring
    2. In atrial fibrillation/flutter: baseline ventricular rate > 60 bpm on Holter monitoring or inpatient ECG monitoring
  • Patients with contraindications to permanent pacemaker implantation
  • Patients with moderate or greater valvular stenosis or regurgitation.
  • Patients with dyspnea not attributable to heart failure, due to uncontrolled comorbid conditions
  • Pregnant or breastfeeding women.
  • Patients who have refused active treatment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Optimized pacing strategy

Optimized Pacing Strategy

  • Definition of Optimal Heart Rate: After permanent pacemaker implantation, a hemodynamic evaluation will be performed using right heart catheterization with stepwise incremental pacing rates of 60, 70, 80, and 90 bpm. If the optimal heart rate is identified at one of these 10-bpm intervals, additional assessments will be conducted in 5-bpm increments around that rate to further refine the optimal pacing rate.
  • Invasive hemodynamic parameters assessed include: Mean pulmonary capillary wedge pressure, Cardiac output (thermodilution)
  • The optimal heart rate is defined as the pacing rate associated with the lowest mean pulmonary capillary wedge pressure or highest cardiac output.
  • To ensure hemodynamic stabilization, a 5-minute washout period will be applied between rate changes.
  • To minimize the confounding effects of intrinsic bradycardia below 60 bpm, optimized pacing will be performed after a stabilization period of 2 weeks following permanent pacemaker.
Procedure: Adjustment of the pacemaker/ICDs lower rate limit (LRL)
Optimized Pacing Strategy
Active Comparator: Conventional pacing strategy

Conventional Pacing Strategy

• The conventional pacing group will have the pacemaker's lower rate limit set at a fixed 60 bpm, in accordance with current standard practice.
Procedure: Conventional lower rate (60bpm)
Conventional Pacing Strategy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Kansas City Cardiomyopathy Questionnaire
Time Frame: From enrollment to 1year after the procedure
Higher scores indicate better health status and a higher quality of life, score 0 to 100
From enrollment to 1year after the procedure

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
NTproBNP
Time Frame: From enrollment to 1year after the procedure
pg/mL (picograms per milliliter)
From enrollment to 1year after the procedure
Functional status (NYHA class)
Time Frame: From enrollment to 1year after the procedure
class I to IV, higher NYHA classes indicate poorer functional status.
From enrollment to 1year after the procedure
Distance in 6-minute walk test
Time Frame: From enrollment to 1year after the procedure
m
From enrollment to 1year after the procedure
Occurrence of atrial fibrillation
Time Frame: From enrollment to 1year after the procedure
Documented incidence of atrial fibrillation on 12-lead ECG
From enrollment to 1year after the procedure
Atrial fibrillation burden
Time Frame: From enrollment to 1year after the procedure
Atrial fibrillation burden(%) recorded by CIEDs
From enrollment to 1year after the procedure
Invasive hemodynamics parameters in right heart catheterization
Time Frame: At the time of CIED implantation
pressure of RA, RV, PA, PCWP as mmHg Cardiac output as L/min (Liters per minute)
At the time of CIED implantation
CIED Battery longevity
Time Frame: From enrollment to 1year after the procedure
year
From enrollment to 1year after the procedure
All-cause mortality
Time Frame: From enrollment to 1year after the procedure
All-cause mortality rate(%) during 1year follow-up
From enrollment to 1year after the procedure
Cardiac mortality
Time Frame: From enrollment to 1year after the procedure
Cardiac mortality rate(%) during 1year follow-up
From enrollment to 1year after the procedure
Re-hospitalization due to all cause
Time Frame: From enrollment to 1year after the procedure
All cause re-hospitalization rate(%) during 1year follow-up
From enrollment to 1year after the procedure
Hospitalization due to heart failure
Time Frame: From enrollment to 1year after the procedure
Hospitalization due to heart failure rate(%) during 1year follow-up
From enrollment to 1year after the procedure
Average heart rate
Time Frame: From enrollment to 1year after the procedure
Average heart rate(bpm) monitored by the device
From enrollment to 1year after the procedure
Heart rate distribution
Time Frame: From enrollment to 1year after the procedure
heart rate distribution recorded in CIED (% of total time) 60bpm to 70 70bpm to 80 80bpm to 90 90bpm to 100 over 100bpm
From enrollment to 1year after the procedure
Pacing burden
Time Frame: From enrollment to 1year after the procedure
Atrial pacing and ventricular pacing burden(%) recorded in CIEDs
From enrollment to 1year after the procedure
Peak oxygen consumption(Peak VO2) and Oxygen consumption at anaerobic threshold(VO2 at AT)
Time Frame: From enrollment to 1year after the procedure
Peak VO2 and VO2 at AT measured by cardiopulmonary exercise test. Both parameter calculated in mL/kg/min
From enrollment to 1year after the procedure
LV ejection fraction (LVEF)
Time Frame: From enrollment to 1year after the procedure
LVEF(%) measured by echocardiogram
From enrollment to 1year after the procedure
E/e' ratio measured by echocardiogram
Time Frame: From enrollment to 1year after the procedure
E/e' ratio, calculated as the ratio of early mitral inflow velocity (E) to early diastolic mitral annular velocity (e'), both velocities measured in m/s.
From enrollment to 1year after the procedure
Cardiac index
Time Frame: From enrollment to 1year after the procedure
Cardiac index(as L/min/m^2) measured with echocardiogram and body surface area
From enrollment to 1year after the procedure
Peak TR velocity
Time Frame: From enrollment to 1year after the procedure
Peak TR velocity(TR V max) measured by echocardiogram (m/s)
From enrollment to 1year after the procedure
Left atrial strain
Time Frame: From enrollment to 1year after the procedure
Left atrial strain(%) measured by echocardiogram
From enrollment to 1year after the procedure
ECG parameters
Time Frame: From enrollment to 1year after the procedure
QRS duration, QT interval, P wave duration, PR interval (as ms)
From enrollment to 1year after the procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Samsung Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 18, 2025

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2028

Study Registration Dates

First Submitted

January 14, 2026

First Submitted That Met QC Criteria

April 28, 2026

First Posted (Actual)

May 1, 2026

Study Record Updates

Last Update Posted (Actual)

May 1, 2026

Last Update Submitted That Met QC Criteria

April 28, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SMC 2025-05-136
  • KCT0010987 (Other Identifier: Korea National Institute of Health)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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