Angela Bygrave Griffiths

Thesis title: Does a raised body mass index affect patient’s quality of life, symptoms and experiences following catheter ablation for atrial fibrillation?

Start year: 2017


Supervisor(s): Professor Eila Watson


I am currently working full time as a Consultant Arrhythmia Nurse at the OUHFT. I work nationally with the British Heart Rhythm Society. I am part of the Medical Advisory Committee for the Atrial Fibrillation Association and Executive Committee member of Arrhythmia Alliance, both of which are charities that offer advice and support to patients and carers with arrhythmias.



Atrial fibrillation (AF) is the most common arrhythmia seen in clinical practice (Camm et al 2010). Previous studies demonstrate that AF may result in high symptom burden and reduced quality of life (Dorian 2000). Rhythm control in the form of catheter ablation has become an established treatment option for AF. Some risk factors are associated with the development and progression of AF, notably, obesity. Emerging evidence suggests that risk factor modification in the management of AF is an important component of the patient pathway.

Prytowsky (2015) reports a dramatic increase in AF burden worldwide, which is also associated with other factors, such as obesity, hypertension and sleep apnoea. Emerging evidence for such factors is seen within key clinical guidelines (Kirchoff et al 2016 and Nalliah et al (2016)), with a focus on obesity. According to the World Health Organisation (2019) obesity is a major global health problem. Epidemiologically, there is an association between obesity and AF, whereby the greater the body mass index (BMI), the higher the risk developing AF (Wang et al 2004). 

The impact of obesity on QoL following ablation

Evidence demonstrates that long-term rhythm control by AF ablation improves quality of life (Ellis and Reynolds 2012), however, less is known about the impact of obesity on QoL following ablation. Two systematic reviews have assessed the relationship between AF and QoL following ablation and related to obesity (Ellis and Reynolds 2012, Zhuang et al 2013). Both reviews show that QoL is significantly improved in patients with a BMI of less than 30, although they have limitations. The systematic review by Zhuang et al (2013) only included observational studies, as no randomised controlled trials (RCT) met their inclusion criteria, or actually existed at that time. 

Furthermore, in the 12 studies included in their meta-analysis, only 3 of those measured QoL. Ellis and Reynolds’ (2012) literature review identified inconsistent results in a number of studies. Cha et al (2008) showed similar QoL improvement in all 3 BMI groups, whereas Wokhlu et al (2010) observed lower QoL scores in obese patients. Mohanty et al (2011) reported significant improvement in overweight and obese groups. A number of factors may explain these confounding results, although comparison between the three groups may be limited by differences in the methodologies of the studies. Other factors may also affect the reported outcomes of AF ablation and these include obstructive sleep apnoea and other conditions associated with obesity (Ellis and Reynolds 2012). These reviews highlight the fact that the impact on QoL following ablation, in those who are obese, is not straightforward and requires further investigation. Furthermore, all studies within the reviews are of a quantitative nature and to date, no qualitative studies exist on the patient experience of AF, the ablation procedure, or knowledge of lifestyle factors in the management of AF.

Research aim

To explore if body mass index affects quality of life, symptoms and patient experience following catheter ablation for atrial fibrillation.

Objectives and outcome measures

ObjectivesOutcome MeasuresTimepoint(s) of evaluation of this outcome measure (if applicable)
Primary Objective
To measure quality of life and symptoms, before ablation and at 3- and 6-months following

SF-36 quality of life questionnaire
Patient Perception Questionnaire (PPQ)

3 months post ablation
6 months post ablation

Secondary Objective
To explore patients’ experiences of AF, ablation and lifestyle factors

Semi-structured interviews
6 months post ablation
Tertiary Objectives
To establish if body mass index affects a patient’s quality of life and symptoms.

SF-36 quality of life questionnaire
Patient Perception Questionnaire (PPQ)

3 months post ablation
6 months post ablation

Study design

The proposed study (Atrial Fibrillation ablation Quality of Life (AFab-QoL) Study) is a mixed-methods study in a single centre. It is a prospective cohort study, in consecutive patients who are referred to a tertiary cardiac centre, for AF ablation. Ethical approval will be sought from Oxford Brookes University Health and Life Sciences Faculty Ethics Committee (FREC), Cambridge South Research Ethics Committee (CSREC) and OUHFT Research and Development Department.

Professional Doctorate in Nursing

The DNurs was a new course, which really appealed to me, particularly the taught component, course structure and level of support.

Although I had 10 years of research experience in London, this was more about helping others with their research, rather than conducting my own. It has been a challenge to get into the mindset of being a novice researcher, with the time that is required, particularly whilst working working full time in the NHS. The past 2 years of the coronavirus pandemic has probably been the most challenging and difficult times of my life. The challenges were not just the time required for study and, particularly the reading, but the technology that is required to undertake a Doctorate.

The taught component has been really useful to get into the mindset and develop the skill to be a researcher. Stretching my intellect and cohort support are the two main benefits. I have learned a huge amount and try to incorporate my learning into my clinical practice. I would not have remained on the programme this long were it not for the other students in my cohort. Bering a Doctoral student can be stressful, particularly when working full-time and with other family responsibilities. My best strategy for dealing with the challenges is exercise and the great outdoors.

Future plans

Completing my data collection, analysis, and thesis. I already have new ideas for other studies. Publication of my research is important to me and I hope to do so. I would love to find a travel scholarship to enable me to travel to Adelaide and meet the research group who are paving the way for the research into AF and raised body mass index., Twitter: @angiegriffiths