NCT04856267: EXCALIBUR

Exploration of Arrhythmia Burden in Cardiac Amyloidosis Using Implantable Loop Recorders

Completed Last updated 20 January 2026

What this trial tests

trial testing LINQ device - implantable cardiac monitor - referred to in the application as "implantable loop recorder" or "ILR") in Arrythmia in 110 participants. Completed in 1 October 2025.

Timeline

27 May 2021

Primary endpoint
1 July 2025

1 October 2025

Quick facts

Lead sponsor	Marianna Fontana
Status	Completed
Study type	OBSERVATIONAL
Enrollment	110
Start date	27 May 2021
Primary completion	1 July 2025
Estimated completion	1 October 2025
Sites	1 location across United Kingdom

Drugs / interventions tested

• LINQ device - implantable cardiac monitor - referred to in the application as "implantable loop recorder" or "ILR")

Conditions studied

• Arrythmia — all drugs for Arrythmia →
• Cardiac Amyloidosis — all drugs for Cardiac Amyloidosis →
• Sudden Cardiac Death — all drugs for Sudden Cardiac Death →

Sponsor

Marianna Fontana

Who can join

18 and older, any sex, with Arrythmia or Cardiac Amyloidosis. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

The overall aim of this study is to improve our understanding of the effects of the build-up of amyloid deposits in the heart, in particular, our understanding of the risk of abnormal heart beats, or rhythms, associated with people with cardiac (heart) amyloidosis. Symptoms such as palpitations (fast, strong or irregular heart beat) and blackouts are common in people with cardiac amyloidosis, but there is not enough information on what causes this. At present, there is also not enough information on when they occur, how often they happen, and which patients are at risk of having serious, life-threatening types of abnormal heart rhythms.

Some of these abnormal heart rhythms can be treated with medicine; others need electronic devices (e.g. pacemakers) implanted or inserted in the heart to prevent serious harm. The information on when is the best time to implant these life-saving devices remains limited. In this study, a small device known as an implantable loop recorder (ILR) will be implanted under the skin on the chest wall to continuously monitor participants' heart rhythm.

This will help us answer some of the questions about what causes the abnormal heart rhythms, when they happen, and which patients are particularly likely to have them. Furthermore, it may help us to identify earlier, rather than later, those who are at risk of developing abnormal heart rhythms. This may lead to improvements in the care of people with cardiac amyloidosis in the future. Participants may not directly benefit from taking part in this study; however, there is a chance that the ILR may reveal heart rhythm abnormalities in some participants which might not be picked up otherwise, and so may lead to a change in their treatment.

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Exploration of Arrhythmia Burden in Cardiac Amyloidosis Using Implantable Loop Recorders: The EXCALIBUR Study.
   Ioannou A, Patel R, Mansell J, Sheikh A, et al · · 2026 · PMID 42201646 · DOI 10.1016/j.jacc.2026.04.030