In the second part of the experiment, they observed the health of 88 patients, who had heart valve replacement surgery, during their stay at the hospital. They also tested their heart tissue samples.
After 12 days, they found that "post-surgery heart damage is more common among people who have heart surgery in the morning," lead author David Montaigne said in a statement.
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But why is that?
Scientists are associating the time of the surgery with the body’s biological clock. The heart tissue samples revealed nearly 300 genes linked to the circadian clock. They were more active in the afternoon than morning, the study revealed.
"Our findings suggest this is because part of the biological mechanism behind the damage is affected by a person's circadian clock, and the underlying genes that control it. As a result, moving heart surgery to the afternoon may help to reduce a person's risk of heart damage after surgery," Montaigne said.
Scientists hope to conduct more studies to confirm their results. They said they may even be able to develop medication that can alter the circadian clock in preparation for open heart surgery.