Comparing Three Types of Specialist Pacemakers to Improve Heart Function and Reduce Rhythm Problems in Heart Failure
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18+
SponsorImperial College London
About this trial
The goal of this clinical trial is to find out which type of specialist pacemaker-known as cardiac resynchronisation therapy (CRT)-works best for people with heart failure and a delay in how the lower chambers of the heart beat together (called electrical dyssynchrony).
The main aims of the study are:
To compare the effects of conventional biventricular pacing (BVP), conduction system pacing (CSP) and left-bundle optimised CRT (LOT-CRT) on heart failure symptoms and heart rhythm problems over six months.
To explore how these pacing methods affect heart muscle strength, electrical activity, and overall heart function.
Participants will:
Attend four hospital visits over a six-month period.
At Visit 1, meet a member of the research team to discuss the study and have screening tests to check eligibility. Participants will also have a smartphone app installed and receive training on how to record their daily heart failure symptoms.
At Visit 2, have a CRT pacemaker implanted. The type of pacemaker will be chosen at random, with a 1 in 3 chance of receiving:
* Biventricular pacing (BVP); the current standard treatment * Conduction system pacing (CSP) * LOT-CRT (Left-bundle optimised CRT); a combination of both
At Visit 3 (around 12 weeks after implantation) and Visit 4 (6 months after implantation), take part in routine follow-up assessments to check the pacemaker and heart function.
At Visits 2 and 4, also undergo non-invasive electrical mapping tests, including wearing a specialised vest and having a low-dose CT scan of the chest. These tests help researchers understand how the heart's electrical system responds to different pacing methods.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Symptomatic heart failure (NYHA II-IV)
Reduced ejection fraction (LVEF≤40%)
Prolonged QRS duration (≥130ms) and left bundle branch block ECG morphology or very prolonged QRS duration (>150ms) and non-left bundle branch block ECG
Optimal medical therapy for HF
Disqualifiers
Unable to provide informed consent
<18 years old
Pregnant patients (with female patients of childbearing age requiring a negative urine BHCG)
Trial design
Design model
Parallel
Treatments tested in this trial
Biventricular pacing
DeviceCardiac resynchronisation therapy with one lead to right ventricular endocardium and one lead to left ventricular epicardium, accessed via the coronary sinus.
Conduction system pacing
DeviceCardiac resynchronisation therapy with single lead targeting direct capture of the conduction system. Primary target should be left bundle area, with backup target of His bundle. If direct capture of the conduction system cannot be achieved by conventional clinical criteria, left septal pacing targeted at the left bundle branch area will be accepted.
Left bundle optimised cardiac resynchronisation therapy
DeviceCardiac resynchronisation therapy delivered by conduction system optimised hybrid configurations. Primary configuration should be conduction system pacing lead targeted at the left bundle area combined with left ventricular epicardial lead accessed via the coronary sinus (LOT-CRT). Backup configuration of conduction system pacing lead targeted at the His bundle combined with left ventricular epicardial lead accessed via the coronary sinus (HOT-CRT).
Treatment groups
60 Participants
are divided into 3 treatment groupsGroup A: Biventricular pacingActive comparator 1 intervention
Group B: Conduction system pacingExperimental treatment 1 intervention
Group C: Left bundle optimised cardiac resynchronisation therapy (LOT-CRT)Experimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Primary outcome: Daily ordinal symptom score with clinical over-rides
Daily ordinal scale with mobile application based assessment of quality of life (using visual analogue scale), with clinical over-rides as detailed below: 1. Death 2. Intractable symptoms leading to trial exit/unblinding 3. Heart failure hospitalisation 4. Non-heart failure hospitalisation 5. Appropriate implantable cardioverter defibrillator therapy (anti-tachycardia pacing or shock, deemed appropriate as per clinical care team interrogating device) 6. Symptom score (1-600, with 1 representing minimum limitation from patient ascribed heart failure symptom and 600 representing maximum limitation)
Time frame
From randomisation to 6-months post device implant2
Primary arrhythmia outcome
Ordinal arrhythmia scale using clinical endpoints as detailed below: 1. Death 2. Appropriate implantable cardioverter defibrillator therapy (anti-tachycardia pacing or shock, deemed appropriate as per clinical care team interrogating device) 3. Sustained ventricular arrhythmia (VA) (\>30s of rhythm determined to be ventricular in origin by clinical team on device interrogation) 4. Sustained atrial arrhythmia 5. Non-sustained VA 6. \>10% ventricular ectopy on 24h ECG
Time frame
From randomisation to 6-months post device implant3
Primary contractility outcome
Ordinal contractility scale using clinical endpoints as detailed below: 1. Death 2. Intractable symptoms leading to trial exclusion/unblinding 3. Heart failure hospitalisation 4. Non-heart failure hospitalisation 5. Left ventricular ejection fraction (measured on transthoracic echocardiogram)
Time frame
From randomisation to 6-months post device implantSecondary outcomes
1
Rate of death
Death, any cause
Time frame
From randomisation up to 36 months, or death from any cause, whichever came first.2
Number of participants with intractable symptoms leading to trial exit/unblinding
Intractable symptoms leading to exit of trial considered to be a single event. Symptoms will be assessed routinely at a single remote consultation with a blinded research team member 1-4 months after device implant. If at this visit or after a patient directed consultation, symptoms are felt to have deteriorated after the device implant likely due to the device, the case will be discussed with the blinded principal-investigator to adjudicate. If the conclusion is that the deterioration is device mediated, the patient will be unblinded, exit from the trial and the device will be programmed to whatever is felt to be optimal by the clinical team.
Time frame
From randomisation up to 36 months, or intractable symptoms leading to trial exit/unblinding, whichever came first.3
Rate of heart failure hospitalisation
Adjudicated unplanned heart failure acute care (hospital admissions or ambulatory diuretic therapy i.e. diuretic lounge visit)
Time frame
From randomisation up to 36 months4
Rate of non-heart failure hospitalisation
Adjudicated unplanned non-heart failure acute care (hospital admissions or ambulatory service i.e. ambulatory emergency clinic).
Time frame
From randomisation up to 36 monthsSponsors and contacts
Click on the lead sponsor to view all of their trials.
Imperial College London
Lead sponsor
Imperial College Healthcare NHS Trust
Collaborator
Source ClinicalTrials.gov