Atrial Fibrillation (AF) is the most common heart rhythm disturbance seen in clinical practice. AF increases the risk of stroke five-fold and is associated with increased risk of heart failure and mortality. Early detection, diagnosis and treatment of AF with oral anti-coagulation can help reduce the incidence of potentially devastating strokes. In the South Asian population there is a high rate of stroke and transient ischaemia attacks (also known as "mini strokes"), however, it has been reported that the prevalence of AF is significantly lower compared to Caucasians. Paradoxically South Asians have a greater prevalence of cardiovascular risk factors such as hypertension, diabetes and coronary artery disease, traditionally associated with the development of AF. The reasons for this are not understood and have not been fully researched. South Asians have not been well represented in large clinical trials. Therefore, investigating this paradox would lead to better understanding of the ethnic differences in the aetiologies of both stroke and AF, and the interaction between these two diseases.
Knowledge generated from this study will help answer questions on whether AF treatment guidelines drawn from clinical trials can be extrapolated to specific ethnic groups, and whether these treatment strategies need to be tailored according to ethnicity. Furthermore, the recent COVID-19 pandemic has highlighted the impact ethnicity can play in the aetiology of disease. We would like to further analyse disparities in the risk (Ethnicity, age, socioeconomic status) and cardiovascular outcomes of COVID-19 between the BAME and Caucasian populations.
Atrial Fibrillation (AF) is the most common arrhythmia seen in clinical practice, affecting approximately 1.4 million people in the UK.[1] AF is a major causative factor for ischaemic stroke.[2] Identifying patients with AF is vital for the prevention of stroke and its consequences. The CHA2DS2-VASc score is used to determine AF and stroke risk based on several risk factors.[3] As part of the interaction between ethnicity, AF and stroke we need to investigate differences in risk factors, compliance of prescription and dosing.
Rates of AF are lower amongst South Asians,[6,7,8] despite having many of the established risk factors for AF. It has also been shown that there are fewer pacemakers and implantable cardioverter defibrillators being implanted in South Asians.[9,10] Suggestions as to why the prevalence of AF is lower than expected in South Asians include a lower attendance to medical services.[7,8,11] There may also be a genuine lower incidence of AF in South Asians despite a similar (or worse) risk factor profile compared to Caucasians. More importantly, stroke rate is high in South Asians. Therefore the mechanisms underlying the interactions between risk factors in the causation of stroke may be different in different ethnicities.
This will be an observational cohort study of individuals with and without a diagnosis of AF and of South Asian, African Caribbean and Caucasian ethnicity. Poisson regression will assess whether AF incidence and the co-morbidities associated with AF, differ between ethnicities. Survival models will investigate the association between AF and subsequent risk of heart failure, TIA, stroke or mortality. An interaction between AF and ethnicity will be included to explore whether risk of events and AF differs by ethnicity. To investigate disruptions to AF detection and management as a result of COVID-19 pandemic, we will employ an interrupted time series analysis framework, stratified by ethnic group.
Atrial fibrillation, transient ischemic attack (TIA), myocardial infarction, ischemic stroke, heart failure, mortality, prescription (and pick-up) of oral anticoagulants (both warfarin and non-vitamin K OACs) and antiarrythmic drugs, referral rates for pacemakers and implantable cardioverter defibrillators, hospital admissions, diagnosis of COVID-19.
G. Andre Ng - Chief Investigator - University of Leicester
Clare Gillies - Corresponding Applicant - University of Leicester
Akash Mavilakandy - Collaborator - University of Leicester
Clare Gillies - Collaborator - University of Leicester
Francesco Zaccardi - Collaborator - University of Leicester
Kamlesh Khunti - Collaborator - University of Leicester
Nilesh Samani - Collaborator - University of Leicester
Safoora Gharibzadeh - Collaborator - University of Leicester
Sharmin Shabnam - Collaborator - University of Leicester
Zakariyya Vali - Collaborator - University of Leicester
Bharat Sidhu - Collaborator - University of Leicester
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation