Co-operation reaps rewards

Volume 6 Number 8 August 9 - September 12 2010

The University of Melbourne students scoop NHMRC prizes. By Maryrose Cuskelly.

University of Melbourne medical students took first, second and third prizes in the finals of the recent National Health and Medical Research Council (NHMRC) Student Research Competition, held in Hobart on Tuesday 6 July.

All three students are currently studying in the Department of Cardiovascular Sciences at the Austin Hospital and worked closely with each other to prepare for the competition. According to Mr Philip Hayward, Consultant Cardiac Surgeon at the Austin Health and Honorary Clinical Fellow, University of Melbourne, the students’ success “demonstrates the strong academic credentials of the cardiac department.”

Sarah Lonie, a fourth year student, won first prize for her project, ‘Depression and Autonomic Nervous System Function in Heart Failure’. Heart failure is a condition where patients are physically limited because of weakness in the heart muscle that can be caused by things such as heart attacks or high blood pressure. Heart failure patients have an imbalance of the autonomic nervous system with more sympathetic (adrenaline) and less vagal (generally associated with a slower heart rate). The ‘sympatho-vagal’ balance can be assessed by examining the small variations in heart rate that occur, such as with normal breathing.

It is also known that patients with heart failure are three times more likely to be depressed than the normal population and that the more depressed heart failure patients have a shorter life expectancy.

Ms Lonie found that the more severely depressed heart failure patients had a detrimental increase in sympatho-vagal balance, which might explain their potentially increased mortality.

Her research follows the considerable work done in this field by her supervisors, Professor David Hare, the Director of Research in the Department of Cardiology at Austin Health and Andrew Stewart, Research Fellow at the Department of Cardiology and University of Melbourne PhD candidate in the Psychology Department.

Ying-Yan Zhu, also a fourth year student, took second prize for her one-year research project, ‘The Effect of Lipid Exposure on Graft Patency and Clinical Outcomes after Coronary Artery Surgery: Arteries and Veins are Different.’ This project was part of a large randomised trial, the Radial Artery Patency and Clinical Outcomes (RAPCO) trial, which has been run at Austin Health over the past 15 years by University of Melbourne’s Professors Brian Buxton and David Hare.

Traditionally, vein from a patient’s leg has been used as a ‘conduit’ in bypass surgery to carry blood around blockages in the heart. Over the past decade, there has been a trend to use arteries from the arm or from behind the breast-bone, because of growing evidence that these grafts might last longer. This move has been largely led by cardiac surgeons in Canada and Victoria with Professor Buxton as one of the leading academics in this field.

Ms Zhu’s study examined why using arteries appear to bring better results for patients. When studying over 6000 serial cholesterol and blood fat readings from over 400 patients up to 11 years after their operations, she found that despite the best efforts of doctors and patients, their cholesterol readings remain above recommended levels. However, arterial grafts appeared unaffected by the degree of high fat exposure, pointing to possible superior ‘fat resistance’ of arteries.

Coronary artery disease is the single biggest killer in the world and coronary bypass surgery one of the most commonly performed operations, particularly in the West. In the rapidly-industrialising countries of India and China, the rate is also rising with tens of thousands of bypass operations performed every year. Given that coronary artery bypass graft is a very common operation, this could prove to be an important contribution to the treatment of a global health problem. Ms Zhu was supervised by Mr Philip Hayward.

Mr Hayward also supervised William Shi, a final year student, in his project, ‘Training in mitral valve surgery need not affect early outcomes or late survival: a multicentre analysis of 2,216 procedures’, which won third prize. William had previously honed his research skills as a fourth year BMedSci student at Austin Health, with a project validating depression measures in cardiac patients, research that has resulted in international presentations and peer-reviewed publications for William.

The mitral valve lies deep near the centre of the heart. Consequently surgery on the valve is technically complex, carries a significant risk of mortality and is difficult for a surgeon supervising a trainee to observe. As a result, mitral surgery is sometimes regarded as carrying more risk when performed by a trainee surgeon.

Mr Shi tested the veracity of this view by studying the impact of surgical training on patients’ outcomes after mitral valve surgery. He compared the results of operations performed by trainee surgeons with those by specialists. Reassuringly, he found that patients were exposed to no greater levels of risk when operated on by trainees. This was the case even when the data was corrected for risk factors, and taking into account that more experienced surgeons may operate on more complex cases.

According to Mr Hayward, the Melbourne students’ success in the NHRMC competition is testament to the value of teamwork.

“They helped each other compose and practise their talks, encouraged each other with their research and showed each other how to do statistical tests,” says Mr Hayward who accompanied the students to Hobart.