Afternoon is the ‘best time for heart surgery’

Researchers say patients have an increased chance of surviving open heart surgery if done in the afternoon.

The research, which was published in the Lancet, attributed this to the body’s internal clock, suggesting that the heart is better suited to withstand surgery in the afternoon than in the morning.

While performing open heart surgeries, doctors have to stop the heart to perform operations including heart valve replacements and this puts the heart under stress as the flow of oxygen is reduced.

Bart Staels from the Institut Pasteur de Lille, who participated in the research, told the BBC: “We don’t want to frighten people from having surgery – it’s life saving,” adding that it would be impossible for hospitals to conduct surgeries only in the afternoon.

“If we can identify patients at highest risk, they will definitely benefit from being pushed into the afternoon and that would be reasonable.”

The risk of heart attack or stroke has been known to be highest in the morning while the heart and lungs work at their peak in the afternoon.

John O’Neill, from the UK medical research council’s laboratory of Molecular Biology, said: “Scientifically it is not hugely surprising, because just like every other cell in the body, heart cells have circadian rhythms that orchestrate their activity.

“Our cardiovascular system has the greatest output around mid/late-afternoon, which explains why professional athletes usually record their best performances around this time.”

Staels said researchers went to great lengths to show that the difference in survival rates was not due to the surgeons.