Leadless Versus Conventional Pacemakers: Effects on Heart Function and Heart Failure
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AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults who need a permanent pacemaker for a slow heartbeat and whose heart pumping function is above 40%. Either a leadless or a wired pacemaker must be possible for them.
- Age
- 18 years or older.
- Sex
- All sexes can join.
- Disease stage
- Slow heartbeat needing permanent ventricular pacing, such as permanent atrial fibrillation with slow ventricular response, high-degree atrioventricular block, or pacing after atrioventricular junction ablation. Left ventricular ejection fraction above 40%, measured within 14 days before the implant.
- Earlier treatment
- No prior treatment requirement is stated.
- Biomarker or test result
- Left ventricular ejection fraction above 40%.
Main reasons for not taking part
- Needs a defibrillator, cardiac resynchronization therapy, or chronic atrial pacing
- Heart attack or active myocarditis in the last 3 months
- Severe right ventricle dysfunction
- Active infection or endocarditis
- Severe kidney problems (eGFR below 20 mL/min/1.73 m2) or dialysis
Read by machine on 11 November 2026.
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Karl Landsteiner University of Health Sciences
- Trial code
- NCT07929467
- Record updated
- 10 November 2026
- Original description
People with a slow heart rhythm may need a permanent pacemaker. Conventional pacemakers use a device placed under the skin and wires that pass through veins into the heart. Leadless pacemakers are placed directly inside the heart without a chest pocket or these wires. Both approaches can provide pacing, but their effects on heart function and heart-failure-related problems need to be compared.Read full original descriptionShow less
Leadless Pacing and Heart Failure: A Prospective, Randomized, Open-Label, Non-Inferiority Trial
People with a slow heart rhythm may need a permanent pacemaker. Conventional pacemakers use a device placed under the skin and wires that pass through veins into the heart. Leadless pacemakers are placed directly inside the heart without a chest pocket or these wires. Both approaches can provide pacing, but their effects on heart function and heart-failure-related problems need to be compared.
LEAP-HF will compare an indication-adapted leadless pacemaker strategy with a conventional transvenous pacemaker strategy in 760 adults for whom either approach is clinically appropriate. Participants must have a left ventricular ejection fraction above 40% and must not require a defibrillator, cardiac resynchronization therapy, or chronic atrial pacing. Participants will be assigned by chance, in equal proportions, to the two strategies. The device and pacing mode will be selected according to the participant's clinical indication within the assigned strategy.
The main question is whether the leadless strategy is not unacceptably worse than the conventional strategy for pacing-induced cardiac dysfunction during 12 months of follow-up. This outcome includes a qualifying deterioration in heart pumping function, pacemaker syndrome, heart failure requiring hospitalization, or an upgrade to cardiac resynchronization therapy. The prespecified non-inferiority margin is an absolute difference of 7 percentage points.
Assessments include heart ultrasound, pacemaker checks, an electrocardiogram, a blood test for NT-proBNP, symptom assessment, and questionnaires about health and quality of life. There will be a telephone contact at 6 weeks and in-person visits at 6 and 12 months after implantation. The study will also compare heart function, complications, further procedures, and deaths. Participants and treating teams will know which pacing system was implanted; selected clinical events will be reviewed by an independent committee unaware of the assigned treatment.
Inclusion: Age 18 years or older; Guideline-based indication for permanent ventricular pacing for which both leadless and transvenous strategies are clinically appropriate, such as permanent atrial fibrillation with slow ventricular response, high-degree atrioventricular block, or pacing after atrioventricular junction ablation; Baseline left ventricular ejection fraction above 40%, assessed within 14 days before implantation and before randomization. Absence of a guideline-based indication for cardiac resynchronization therapy or an implantable cardioverter-defibrillator must be confirmed separately; No guideline-based requirement for chronic atrial pacing, such as symptomatic sinus node dysfunction requiring an atrial lead; No baseline indication for cardiac resynchronization therapy or implantable cardioverter-defibrillator therapy; Technical and clinical feasibility of both leadless and transvenous implantation approaches; Written informed consent and willingness and ability to comply with follow-up for at least 12 months.
Exclusion: Current guideline-based indication for cardiac resynchronization therapy or an implantable cardioverter-defibrillator, or a requirement for chronic atrial pacing; Severe right ventricular dysfunction, for example tricuspid annular plane systolic excursion below 12 mm or right ventricular systolic tissue Doppler velocity below 8 cm/s, where advanced right ventricular failure could confound the pacing strategy comparison; Active systemic infection or endocarditis; Severe uncontrolled coagulopathy or a bleeding disorder precluding safe implantation; Life expectancy below 12 months due to cardiac or noncardiac comorbidity; Recent myocardial infarction or active myocarditis within 3 months, or another planned cardiac intervention likely to affect left ventricular ejection fraction within 12 months, such as severe valve disease requiring intervention; Severe renal dysfunction, defined as estimated glomerular filtration rate below 20 mL/min/1.73 m2, or dialysis dependence; Anatomical or clinical contraindication to leadless implantation, such as a mechanical tricuspid valve prosthesis or known intracardiac thrombus, or contraindication to transvenous implantation; Pregnancy; Inability to provide informed consent or adhere to follow-up; Strong patient preference for a specific pacing strategy.