A Mechanistic Exploratory Study of AF-induced Cardiac Dysfunction and Symptoms

Summary

Although the heart rhythm disorder Atrial Fibrillation (AF) affects 2% of the population, the impact it has on an effected individual can be highly variable. Some people are asymptomatic whilst others can experience debilitating symptoms or heart failure (HF)- weakness of the heart muscle. The reason why this variability exists in unknown and how AF actually drives HF is unclear. HF can also be caused by many other reasons and it can be difficult to identify those patients with HF caused by AF versus patients with AF but their HF is due to a different reason. This is important as it would help us to identify those patients most likely to improve their heart function after the treatment of AF and thus gain more from invasive treatments like AF catheter ablation; which is effective at restoring normal heart rhythm but has some risks attached.

The investigators suspect the characteristics of the AF, such as how irregularly it makes the heartbeat, can be used to predict who will respond better. Studies of heart cells in the lab as well as animal models have suggested this characteristic may be the cause of AF-induced heart muscle weakness and reduce cardiac output, making it a potential predictor that can be measured. Other potential predictors will be measured during pre-procedural scans and tests too. The investigators will also explore whether there are predictors of which patients gain the most symptomatic benefit and gain insight into why some people develop symptoms of AF, whereas others do not.

By studying the structural and functional sequelae of catheter ablation in patients with HF the investigators hope to better understand the relationship between the two diseases.

Conditions

• Atrial Fibrillation
• Heart Failure

Interventions

OTHER

Holter monitoring

Assessment of HRV shall be performed in all enrolled patients. Ventricular HRV will be derived from a continuous 24-hour period of a 48-hour ambulatory Holter recording during AF. Participants will be requested to avoid alcohol and caffeine from 24-hours prior to fitting and any activity more strenuous than walking for the recording duration. After initial fitting, a 20-minute high-resolution ECG recording will be performed lying supine at rest.

OTHER

stress echocardiography

Echocardiography will be performed using a GE Vivid 9 echocardiography machine (Vingmed-General Electric, Horten, Norway) equipped with a phased-array 3.5 MHz transducer. All measurements will be made according to the guidelines set by the British Society of Echocardiography.

OTHER

Cardiac MRI

Contraindications to MRI will be excluded using the appropriate departmental screening forms. A trained scanner operator or radiographer will co-ordinate and supervise the scan. Cardiac MRI will be performed at 1.5T (Aera, Siemens Healthineers, Erlangen, Germany) with a protocol consisting of cine imaging, stress and rest perfusion, and late gadolinium enhancement (LGE).

OTHER

Patient questionnaires

Two validated Health Related Quality of Life (HRQoL) surveys designed for patients with AF will be used; the AF Effect on Quality of Life (AFEQT) and Barts AF Patient reported objective measure (PROM).

Sponsors & Collaborators

• Barts & The London NHS Trust

  lead OTHER

Principal Investigators

• Richard Schilling · Barts & The London NHS Trust

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

21 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-01-21

Primary Completion

2024-10-31

Completion

2024-10-31

Countries

• United Kingdom

Study Locations