OPEN heart surgery is more likely to be successful if the operation is in the afternoon, rather than the morning.

A study suggests patients who have open heart surgery in the afternoon are 50 per cent less likely to suffer tissue damage, heart failure or death.

It is all down to the operation synchronising with the body’s circadian clock and the heart being better able to repair itself in the afternoon.

French scientists suggested it would be better for patients if surgery was postponed to after lunch as there were fewer complications.

They identified a link between the genes that control the body’s internal clock which tells us when to sleep, eat and wake up and our risk of heart damage and major cardiac events after heart surgery.

It identified nearly 300 genes linking the circadian clock to heart damage.

Following open heart surgery, some patients may develop heart damage impacting on the heart’s ability to pump blood, which can lead to heart failure and a heightened risk of death.

Previous studies found cardiovascular events such as heart attacks that happen in the morning may be associated with a higher risk of the damage, compared to afternoon events.

Professor David Montaigne at the University of Lille said: “Part of the biological mechanism behind the damage is affected by a person’s circadian clock.”