Postgraduate Scholarships

Integrated Research Module Postgraduate Scholarship  - Restoring the balance: Heart health of wāhine, Fafine, Va’ine, Fifine and Women in Aotearoa

The purpose of this research is to examine the differences in female heart rhythm detection, diagnosis, treatment, and management.

Heart disease is the leading cause of death in women. Atrial fibrillation (AF) is a common heart rhythm that can lead to serious conditions, such as stroke and heart failure. Women generally have more strokes, a worse quality of life, a lower rate of referral for treatment and higher rates for older women. Despite this, our understanding of the sex differences of AF is limited. A primary reason for the lack of understanding is the lower number of women in clinical trials, with an average percentage of 26.8%.

The initial aim is to assess Holter monitor recordings to identify any differences in abnormal heart rhythms. The second aim is to examine a registry of patients who have been treated for AF to see if there are any sex differences in the outcomes of AF therapy. The third aim is to understand patients' experience of AF through a questionnaire to gain insights into women's and men's journey with AF, from symptoms to treatment. Data will be analysed to determine the sex differences for all aims to provide crucial information on why women present with AF later in life and are often more symptomatic.

This project focuses on how our novel pacemaker, which restores the respiratory sinus arrhythmia (RSA), affects the structure of muscle cells in the failing heart. This RSA pacemaker doubles the pumping capacity of the heart relative to current optimal medical therapy. Recent data from our group shows that RSA pacing works by modulating proteins linked to energy metabolism in the heart. However, we do not know where these proteins are located within the muscle cells of the heart. 

In a recently completed Summer Research Studentship, I identified that a key cellular structure improved by RSA pacing was the mitochondria, intracellular organelles that are the powerhouses of cells. I hypothesise that RSA pacing is reparative to mitochondria. 

In this research project, I will use a novel kind of fluorescence imaging called Stimulated Emission Depletion (STED) microscopy that provides a tenfold increase in resolution compared to other microscopes (e.g. confocal) to map the location of identified protein targets, providing nanoscale details on how the structure of the mitochondria is recovered by RSA pacing. These data will provide the first mechanistic insight into how the RSA pacemaker works.

Pacific Postgraduate Scholarship

Since Māori and Pacific populations are at a higher risk for Cardiovascular disease (CVD), this research aims to develop CVD predictive datasets for these groups through pulse wave velocity (PWV) analysis and to investigate the accuracy of bioelectrical impedance analysis (BIA) technology for measuring PWV, thereby improving CVD risk detection.

Arterial stiffness is defined as the gradual loss of elastin fibres within the arterial wall, resulting in the accumulation of stiffer collagen fibres. It refers to the reduced capability of physiological expansion and contraction of arteries in response to changes in blood pressure (BP). Arterial stiffness is measured as carotid-femoral pulse wave velocity (cf-PWV) and is well established as an additional, independent predictor of cardiovascular disease (CVD) events, particularly in individuals with diabetes, obesity, or a history of stroke.

There is limited information about the normal reference values of PWV in the New Zealand population, as the current normative PWV utilised is based on overseas datasets. Bioelectrical impedance analysis (BIA) is a technique for estimating body composition by sending an electric current through the body, and measuring the voltage to calculate the impedance (resistance and reactance). This method can be used to measure pulse wave velocity, which does not require a skilled operator to measure or locate the femoral artery.

Open Postgraduate Scholarship

This project aims to investigate various aspects of blood vessel structure, function, and regulation in patients with POTS and matched controls. Specifically, we will measure artery stiffness, blood vessel function, and vein function in patients with POTS and matched controls. We will then investigate the nerve control of blood vessels by measuring muscle sympathetic nerve activity. 

Postural Orthostatic Tachycardia Syndrome (POTS) is a common disorder of the autonomic nervous system that is estimated to affect 1 in 100 people, predominantly young women. 

In POTS, the heart rate increases excessively with standing (> 30 beats per minute within 10 minutes of standing) in the absence of a fall in blood pressure (>20/10 mmHg). POTS has a wide variability in daily functioning, with patients reporting multisystemic symptoms, including dizziness/light-headedness, chest pain, shortness of breath, fatigue, brain fog, and fainting. 

Normally, on standing, there is a shift of blood into the legs and abdomen due to gravity, inducing a slight increase in heart rate and tightening of the blood vessels to maintain blood pressure. Excessive pooling of blood in the legs is observed in POTS, which is thought to result from impaired tightening or abnormal stretchiness of the blood vessels. However, the exact mechanism underlying this remains unclear in POTS. 

This project will provide an understanding of how the vascular structure, function, and regulation are altered in POTS. Such understanding may help improve and personalise treatments for patients with the syndrome. 

Māori/Pacific Postgraduate Scholarship

Cardiovascular and associated metabolic conditions are major preventable causes of health expectancy gaps, particularly for Māori and Pacific people. Combined population-level and individualised interventions can halve cardiovascular-metabolic risk.

We have already developed and implemented cardiovascular risk prediction algorithms, enabling New Zealand clinicians and policymakers to target at-risk patients and populations. Up-to-date cardiovascular-metabolic risk information for every adult New Zealander is not yet accessible. However, in collaboration with the VAREANZ group, we aim to contribute to the development of a sub-register for cardiovascular-metabolic conditions and to identify areas where significant equity gaps exist in cardiovascular disease.

One area of interest for the VAREANZ group is assessing the efficacy of bariatric surgery on cardiovascular disease risk remission over the longer term (minimum of 10 years post-surgery). This study aims to assess the cardiovascular disease (CVD) risk status of all New Zealanders who have undergone bariatric surgery in Aotearoa and to map the changes in CVD, polypharmacy, and CVD risk over a minimum of 5 years. We will also aim to compare these outcomes by ethnicity to determine whether Māori have equitable outcomes after bariatric surgery.