First patient treated with gene therapy to improve heart bypasses

A heart attack patient has become the first person to be treated in a clinical trial of an experimental gene therapy, which aims to strengthen blood vessels after coronary bypass surgery.

Coronary artery bypass surgery is performed to treat coronary artery disease, which occurs when fatty buildups cause the blood vessels feeding the heart to become narrowed. The replacement blood vessels, sourced from other parts of the body, sometimes fail following surgery as they're not used to the blood pressure coming from the heart.

'Heart bypass surgery is a life-saving treatment for patients with coronary heart disease ... The heart surgeon will typically use one artery and two or more veins as bypass grafts. However, in the years after surgery, the veins commonly narrow and may block, leading to angina, heart attacks and heart failure,' explained Professor Colin Berry, from the University of Glasgow, who led the research.

'Our team has developed a new approach to prevent vein graft failure... We are delighted to be leading this new study, which is designed to clarify the feasibility and potential benefits of this new therapy for patients undergoing heart bypass surgery,' he added.

The patient, 73-year-old John MacDonald, received the new treatment in a clinical trial, which is part of a study called PROTECT. The gene therapy involves treating the grafted vessels during surgery with a viral vector carrying a copy of the gene TIMP-3. This gene encodes a protein involved in tissue remodelling, which the team hopes will strengthen the vessels to prevent failure following the treatment.

MacDonald, who volunteered for the trial following a heart attack in August 2025, said: 'I can't get over how I'm feeling. I was managing to go for walks two or three weeks after getting out of the hospital, I'm driving again now, and I've been doing wee bits around the garden.'

'This pioneering study is an inspiring reminder of how far gene therapy, which was once a distant scientific ambition, has come,' said Professor James Leiper, director of research at the British Heart Foundation, which partially funded the work. 'We look forward to seeing the results of this exciting trial in a few years. While it's early days, positive results would open up opportunities for more patients like John to continue to feel "on top of the world".'