NCT05815745: PROTECT-HF

"Physiological vs Right Ventricular Pacing Outcome Trial Evaluated for bradyCardia Treatment" (PROTECT-HF)

Recruiting now NA Last updated 28 November 2025

What this trial tests

NA trial testing Pacemaker - Physiological pacing in Bradycardia in 2,600 participants. Currently enrolling.

Timeline

5 June 2023

Primary endpoint
4 December 2029

4 December 2029

Quick facts

Lead sponsor	Imperial College London
Phase	NA
Status	Recruiting now
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	double
Primary purpose	treatment
Enrollment	2,600
Start date	5 June 2023
Primary completion	4 December 2029
Estimated completion	4 December 2029
Sites	45 locations across United Kingdom, Ireland, Slovenia

Drugs / interventions tested

• Pacemaker - Physiological pacing
• Pacemaker - Right Ventricular pacing

Conditions studied

• Bradycardia — all drugs for Bradycardia →
• Pacing — all drugs for Pacing →
• Right Ventricular Pacing — all drugs for Right Ventricular Pacing →
• His Bundle Pacing — all drugs for His Bundle Pacing →

Sponsor

Imperial College London

Who can join

18 and older, any sex, with Bradycardia or Pacing. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

The PROTECT-HF multi-centre randomised controlled trial will compare two different pacing approaches for treating patients with slow heart rates. In it the investigators will compare a long-standing standard approach for pacing; right ventricular pacing, with a new form of pacing, physiological pacing (His and Left bundle area pacing) in 2600 patients.

Patients will be allocated at random to receive either right ventricular pacing or physiological pacing. Endpoint measurements will be undertaken at baseline, and at six-monthly intervals post-randomisation. Treatment allocation will be blinded to the endpoint assessor and the patient.

Recruitment and pacemaker implantation will be carried out at each participating centre. The primary analysis will be intention to treat. The investigators will also perform an on-treatment analysis.

2048 patients are needed to detect the expected effect size with 85% power. A total of 2600 patients will be recruited to allow for patient drop-out and crossover.

500-patient sub-study will assess within patient, and between groups, echocardiographic changes over a 24-month period to try and improve mechanistic understanding of PICM (Pacing Induced Cardiomyopathy).

Publications & conference data

6 peer-reviewed publications reference this trial (live from Europe PMC):

1. European Society of Cardiology (ESC) clinical consensus statement on indications for conduction system pacing, with special contribution of the European Heart Rhythm Association of the ESC and endorsed by the Asia Pacific Heart Rhythm Society, the Canadian Heart Rhythm Society, t
   Glikson M, Burri H, Abdin A, Cano O, et al · · 2025 · cited 67× · PMID 40159278 · DOI 10.1093/europace/euaf050
2. New Insights into Pacing Induced Cardiomyopathy.
   Kim SS, Park HW. · · 2024 · cited 6× · PMID 39076559 · DOI 10.31083/j.rcm2504118
3. Implant, assessment, and management of conduction system pacing.
   Vernooy K, Keene D, Huang W, Vijayaraman P. · · 2023 · cited 4× · PMID 37970519 · DOI 10.1093/eurheartjsupp/suad115
4. Physiological pacing: mechanisms, clinical indications, and perspectives.
   Whinnett Z, Naraen A, Vijayaraman P, Cleland JGF, et al · · 2025 · cited 1× · PMID 40679612 · DOI 10.1093/eurheartj/ehaf440
5. Cardiac Resynchronization Therapy and Conduction System Pacing.
   O'Neill TG, Tsushima T, Tayal B. · · 2025 · cited 1× · PMID 40364243 · DOI 10.3390/jcm14093212
6. Conduction System Pacing for Heart Failure.
   Smith NR, Lynch P, Chelu MG. · · 2024 · PMID 39677397 · DOI 10.14503/thij-24-8469