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Title: Trial designs and the evaluation of interventions for stable angina
Author: Thompson, David
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2018
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Percutaneous coronary intervention (PCI) is in widespread use in clinical practice for the treatment of (a) acute myocardial infarction and (b) chronic stable angina. Use of PCI in acute myocardial infarction has consistently demonstrated improvement in major adverse cardiac events in clinical trials however, all trials of PCI in chronic stable angina to date have been carried out in the absence of a double-blind design and therefore the benefits are not clear. The main results of the ORBITA trial showed that in a group of 200 patients with chronic stable angina attributable to single-vessel coronary artery disease and optimally managed using pharmacological anti-anginal agents, there was no significant change in exercise tolerance observed between groups randomly allocated to receive PCI or a sham procedure. In this thesis, I begin with a quantitative overview of the published literature for procedures developed for the treatment of stable angina and show that increasing levels of bias resistance in trial design is associated with smaller sizes of effect and that the largest sizes of effect are seen in studies that lack the design features necessary to resist bias. I go on to explore the accuracy and reproducibility of a physical activity tracking device before using the device in ORBITA trial patients to quantify activity levels in patients following randomisation - the first use of such a device in a clinical trial of PCI. I report the findings of the questionnaire-based evaluations of angina and quality of life which offer unique insight due to the blinded trial design. I then describe the effects of PCI on the myocardium using dobutamine stress echocardiography and explore whether ischaemic burden is related to response to treatment with PCI.
Supervisor: Thom, Simon ; Francis, Darrel Sponsor: National Institute for Health Research
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral