Heart attacks: more deadly in the morning

All content is checked by medical journalists.

The morning is a risky time for the heart: the risk of a heart attack is particularly high - and the heart attacks are more severe and more fatal than at other times of the day. Just why?

How the heart can cope with a heart attack is not only determined by the extent of the damage, but also by the force of the subsequent inflammatory reaction. This in turn is controlled by certain immune cells, the so-called neutrophil granulocytes. They are released from the bone marrow and migrate into the damaged tissue. There they break down the dead heart cells - the first step on the path to recovery, which is associated with inflammatory processes.

Morning invasion

In the early hours of the morning, researchers working with Sabine Steffens from the University of Munich found out, however, that more neutrophils flow to the area of ​​application in the heart than at other times of the day. “A heart attack at this time then triggers an excessive inflammatory reaction,” says Steffens. This worsens the chances of recovery: Due to the increased inflammation, more scars form in the tissue and the heart muscle expands more. This permanently weakens the heart.

Activated immune cells

The researchers also found out why the neutrophils are more active in the morning. A key role is played by a docking point for certain signal substances, the CXCR2 receptor, which sits on the surface of the neutrophil granulocytes. This is influenced by the biorhythm. It is most active as soon as you wake up - and thus incites the neutrophil granulocytes to zealously.

New starting point for therapies

The finding also harbors a possible new starting point for the treatment: "Our study shows that CXCR2 can be an interesting therapeutic target," says Steffens. After the researchers had medically paralyzed the receptor in myocardial infarction mice, this reduced the inflammation and thus the damage to the heart muscle in the animals.

According to statistics from the Robert Koch Institute, around 280,000 people in Germany suffer a heart attack every year. About one in three ends fatally. Around 40 percent of all heart attacks occur in the morning between 6 and 10 a.m. - that's only about 16 percent of the day. (cf)

Source: Press release University of Munich: What makes heart attacks so dangerous in the morning, June 6, 2016

Tags:  digital health Baby Child dental care