Heart Surgery Complications More Likely In The Morning Than Afternoon: Study

Individuals undergoing open-heart surgery in the afternoon may be more likely to have a better outcome than patients with morning surgeries, according to the findings of new research. 

In a study published last week in the medical journal The Lancet, French researchers indicate that complications following heart surgery in the mornings are more likely, including issues like heart attacks during the procedure and heart failure.

Researchers studied nearly 600 patients with severe aortic stenosis, a severe blockage of the aortic heart valve. Patients underwent aortic valve replacement surgery at the Lille University Hospital in Lille, France. They were matched by pairs and assigned to undergo open-heart surgery either in the morning or the afternoon.

Overall, patients who underwent the procedure in the afternoon experienced fewer open-heart surgery complications. Those patients had fewer heart attacks during the surgery, fewer major adverse cardiac events, fewer incidents of acute heart failure, and fewer incidents of cardiovascular death.

During the 500 days after the aortic valve replacement surgery, the incidence of major adverse cardiac events was lower in the group who had surgery in the afternoon, than in the group who had surgery in the morning.

Comparatively, the researchers then followed up with a second study, a randomized trial involving just 88 patients. Half the patients were assigned to undergo surgery in the morning and the other half to undergo surgery in the afternoon.

The findings indicate that during the 12 days following the surgery, levels of troponin were significantly lower in the afternoon surgery group. Troponin is a combination of three proteins essential to heart and skeletal muscle contraction. It is also used as a measure of heart muscle damage. Low levels of troponin indicated higher levels of muscle damage, leading to reduced heart function.

Researchers believe the cause of the differences in outcomes between morning and afternoon surgery is the genetic mechanisms that protect muscle tissue under stress. Those mechanisms may function differently in the morning and afternoon, in all muscle groups, not just the heart.

Researchers emphasize that no one should refuse open-heart surgery based on the time of surgery. Open-heart surgery can potentially save a person’s life, no matter whether it is in the morning or the afternoon. However, doctors should identify patients who may be at higher risk for complications. Those patients should opt for afternoon surgeries instead of morning surgeries. High risk patients include those with diabetes or other metabolic risks.