Abstract
Calcific aortic valve disease is a spectrum between mild thickening of the aortic valve (aortic sclerosis) to severe calcification (aortic stenosis). The burden of disease is increasing globally, and the only effective treatment option is to replace the valve. Significant research work has been undertaken to try to identify medical therapies to stymie the progression of calcific aortic valve disease (CAVD). However, little is known about early CAVD, encompassing aortic sclerosis and mild aortic stenosis. Guidelines recommend monitoring, but timeframes are unclear and the risk of valve-related events in that population is unknown. This makes developing new therapies and designing trials challenging. This thesis describes the outcomes of patients in two cohorts. The first cohort has been previously researched, and we demonstrate an association between lipoprotein(a) (both circulating and genetically predicted), CAVD, and major adverse cardiovascular events. Subsequently, we developed a novel method of extracting and cleaning routinely collected echocardiography reports, and investigated the outcomes in those patients. We discovered that some of those with aortic sclerosis ought to be reclassified as mild aortic stenosis, and make recommendations about repeat imaging on that basis. Using a number of echocardiographic parameters, we identified that structural cardiac damage predicts prognosis similarly in mild and moderate aortic stenosis. Finally, it was found that Māori have similar age-specific rates of CAVD compared to New Zealand Europeans, and that overall differences in population prevalence are likely due to differences in population structure.