Characterisation of clinical and anatomical substrates in risk stratification and management of atrial fibrillation and ischaemic stroke

Atrial fibrillation and ischaemic stroke are dual epidemics in society, both associated with poor clinical outcomes, patient disability and significant healthcare expenditure. The conditions are interrelated with a complex causal association appreciated between atrial fibrillation and stroke development. Although several clinical drivers of disease development and progression have been identified, the role of structural changes within the heart and novel pathogenic risk factors involved in this process are still being explored. This doctorate explores the relationship between novel clinical and structural cardiac factors and their association with disease progression and development of adverse cardiovascular outcomes in patients with non-valvular atrial fibrillation. Towards this end, three articles in this thesis evaluate a cohort of hospitalised patients with non-valvular atrial fibrillation. Study findings from this work identify structural adverse cardiac remodelling associated with progression of atrial fibrillation disease burden, in particular dilatation of the right atrium and impairment of left atrial function. Further, impairment of left atrial function has been found to be associated with atrial fibrillation-related rehospitalisation and adverse cardiovascular outcomes in this cohort. Finally, stratification of patients in the cohort based on their risk factor profile identify a group of patients at highest cardiovascular risk based on burden of both standard modifiable risk factors as well as non-traditional mediators of cardiovascular risk. This doctorate similarly evaluates the role of clinical risk factors and structural cardiac changes in patients with ischaemic stroke and transient ischaemic attack and is presented in four articles in this thesis. Firstly, we evaluate the diagnostic role of subclinical adverse left atrial remodelling in an otherwise healthy cohort of young patients with cryptogenic stroke and compare these changes to both healthy cohorts and those with established paroxysmal atrial fibrillation. Further, we identify temporal changes in cardiovascular risk profiles in a younger stroke cohort. Thirdly, we evaluate the prognostic value of sensitive novel markers of left atrial function in prediction of outcomes in patients with cryptogenic stroke. Finally, markers of left atrial function are placed in a user-defined clinical decision tree for discrimination of cardioembolic stroke subtypes in a cohort of patients with ischaemic stroke.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2024

Author dc:creator

• Bhat, Aditya

• atrial fibrillation
• stroke
• heart atria
• prognosis
• risk factors
• anzsrc-for: 32 BIOMEDICAL AND CLINICAL SCIENCES

Statement dc:rights

• embargoed access
• CC BY 4.0

Licence

• http://purl.org/coar/access_right/c_f1cf
• https://creativecommons.org/licenses/by/4.0/

Language dc:language

en

Identifier

https://doi.org/10.26190/unsworks/30480

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/102962