NCT03781427

Brief Summary

Aims: To explore the clinical effect on exercise tolerance and quality of life, safety and tolerability of pacing at higher outputs in patients with chronic heart failure and a pacemaker. Background: Heart failure (HF) is a very common condition of breathlessness or fatigue associated with heart muscle weakness. In around 30% of people with HF, a pacemaker-based treatment known as cardiac resynchronization therapy (CRT) can improve symptoms and prognosis by retuning the timing of the contraction of the heart. However, the effect of CRT is variable and unpredictable, with around 1 in 3 of people obtaining no obvious symptomatic benefit. One of the reasons for this might be that the pacemaker pulse does not activate all of the heart muscle cells at the same time or at all. In order to provide the longest possible battery life span, the default programming for all pacemakers is to provide a stimulus at an arbitrary level above the capture threshold (at which the spike leads to contraction). Whilst this is reasonable in a normal heart where the aim is to treat a slow heart rate, in heart failure, where the aim is to retune all parts of the heart, it is possible that this is not enough to provide consistent contraction of all heart muscle cells. It is possible that providing a higher output electrical signal from the pacemaker will activate more of the heart muscle cells immediately and thereby improve the contraction of the heart. The investigators think that this might be important at rest, but even more important during activity. This concept has never been tested before in a systematic manner but could have large implications for people with heart failure and existing CRT devices which could simply be reprogrammed to derive greater benefits for patients during everyday activities. Design: The proposed project has two parts: Study 1 - 105 patients with a CRT pacemaker for heart failure but ongoing symptoms will be invited to attend the National Institute of Health Research Clinical Research Facility. Symptoms, medication, hospitalisation information will be collected and a heart ultrasound scan using the pacemaker to increase the heart rate will be done to describe the force frequency relationship. Patients will perform a cardiopulmonary exercise test. Of these patients, 40 will be invited to return for two further visits, to perform an exercise test each time with the pacemaker programmed to its usual output or high output pacing. At each visit, including the heart scans, the order of the programming will be random, and neither the observer nor the patient will know how the device has been programmed. Study 2 - 70 patients will be invited to participate in a longer term study of whether high output pacing is safe, well tolerated and has effects on walk time (on a treadmill) and heart pumping function. Participants will be randomly allocated to one of two groups: high output or standard pacemaker settings. In the high output group, the pacemaker will be programmed to deliver the highest output possible or tolerated. In the standard care group patients will have standard output settings.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
70

participants targeted

Target at below P25 for phase_3

Timeline
Completed

Started Feb 2020

Typical duration for phase_3

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

December 18, 2018

Completed
1 day until next milestone

First Posted

Study publicly available on registry

December 19, 2018

Completed
1.1 years until next milestone

Study Start

First participant enrolled

February 1, 2020

Completed
3.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

July 1, 2023

Completed
1 month until next milestone

Study Completion

Last participant's last visit for all outcomes

August 1, 2023

Completed
Last Updated

November 2, 2022

Status Verified

October 1, 2022

Enrollment Period

3.4 years

First QC Date

December 18, 2018

Last Update Submit

October 31, 2022

Conditions

Keywords

PacemakerCardiac resynchronization therapy

Outcome Measures

Primary Outcomes (1)

  • Change in treadmill based exercise time

    Time (seconds)

    6 months

Secondary Outcomes (5)

  • Quality of life

    6 Months

  • Modified Packer score

    6 months

  • Left ventricular end diastolic and end systolic diameter

    6 months

  • Left ventricular end diastolic and end systolic volumes

    6 months

  • Left ventricular ejection fraction

    6 months

Study Arms (2)

Standard care

ACTIVE COMPARATOR

Cardiac resynchronization therapy: Usual output programming

Device: Cardiac resynchronization therapy

High output

EXPERIMENTAL

Cardiac resynchronization therapy: High output programming

Device: Cardiac resynchronization therapy

Interventions

Left ventricular pacing

High outputStandard care

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Symptomatic heart failure due to left ventricular systolic dysfunction (LVEF\<50%)
  • Willing and able to give informed consent
  • CRT-D or CRT-P device in situ (\>6 months)

You may not qualify if:

  • Angina pectoris symptoms limiting exercise tolerance
  • Unstable heart failure symptoms (medical therapy changes in last three months)
  • Poor imaging quality (details of patients excluded for this reason will be recorded)
  • Calcium channel blocker use (these depress the force of contraction at all heart rates)
  • Uncontrolled heart rate (either atrial fibrillation or sinus rhythm (\>80bts/min))
  • Co-morbidities significantly affecting exercise or symptoms such as severe chronic airways disease or arthritis
  • Haemodynamically significant aortic stenosis

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Leeds General Infirmary

Leeds, United Kingdom

RECRUITING

MeSH Terms

Interventions

Cardiac Resynchronization Therapy

Intervention Hierarchy (Ancestors)

Cardiac Pacing, ArtificialElectric Stimulation TherapyTherapeutics

Study Officials

  • Klaus K Witte

    University of Leeds

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Klaus K Witte, MD

CONTACT

Study Design

Study Type
interventional
Phase
phase 3
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Senior Lecturer in Cardiology

Study Record Dates

First Submitted

December 18, 2018

First Posted

December 19, 2018

Study Start

February 1, 2020

Primary Completion

July 1, 2023

Study Completion

August 1, 2023

Last Updated

November 2, 2022

Record last verified: 2022-10

Locations