Understanding Total-Arterial Graft Use and Outcomes in Heart Bypass Surgery

Mr Justin Ren, Melbourne Health

Postdoctoral Fellowship

Years funded: 2026 - 2028

Coronary artery disease remains a leading cause of death worldwide, occurring when blood vessels supplying the heart become blocked, increasing the risk of heart attacks. Coronary artery bypass grafting is a life-saving surgery that restores blood flow. Traditionally, surgeons use one artery along with multiple veins (single-arterial grafting), taken from other parts of the body, to create these bypasses/conduits. However, arteries and veins are built to do different jobs; arteries transport high-pressure blood to deliver oxygen to body, while veins return blood at low pressure. In bypass surgery, veinous conduit are however used to replace blocked coronary arteries and must deliver high-pressure blood to the heart muscle. Because veins aren’t built for this role, they can become damaged, wear out faster, or get blocked again over time.

Hospitals in the US and Europe are increasingly studying multi-arterial grafting—a step forward by using multiple arteries as conduits, but it unfortunately still relies on vein grafts. Our priority should be delivering the best possible care, not persisting with a compromised vein-dependent approach that may cause harms. To address this, Australia pioneered total arterial revascularisation (TAR), a technique that exclusively uses arteries as conduits, leading to better patient survival, fewer heart attacks, and reduced repeat surgeries. My PhD research has confirmed TAR’s superiority, yet it remains underutilised globally, due to perceived technical challenges and specialised skill requirements.

My project will use a National Cardiac Surgery Registry to investigate how often TAR is performed in Australia, how surgeon experience influences outcomes, and whether hospitals that perform TAR more frequently achieve better long-term survival using artificial intelligence. This will help demonstrate to the world the level of experience required to safely and effectively use TAR. We will also explore whether TAR improves survival for women and Indigenous Australians, who are less likely to receive arterial conduits, experience poorer heart disease outcomes, and have been historically under-researched in cardiovascular field. Targeted research is needed to confirm these benefits and ensure equitable access to this life-saving technique.

As a global leader in arterial grafting, Australia is uniquely positioned to drive the worldwide shift toward TAR. This study will provide critical evidence to support global surgical training, guidelines, and policy recommendations, making TAR more accessible. Findings will be shared widely through scientific publications, international presentations, clinical networks, and public health discussions to transform heart surgery worldwide, improve patient survival, and reduce health inequalities in vulnerable populations.