Corona virus and the heart: maximum performance for the pump

Hypertension is a common ailment. In Germany alone, an estimated 20 to 30 million people have high blood pressure. The risk often goes undetected because suffering causes little or no symptoms. Diagnosis and correct therapy are important, however, because if left untreated, high blood pressure increases the risk of serious complications: Heart failure is one of them, but also stroke, heart attack and kidney failure.

The corona pandemic highlights all of these ailments. Clinical data from several countries show that people with diseases of the cardiovascular system are at higher risk for severe courses.

The trend in Covid-19 was already indicated in mid-February with preliminary data from China: Other diseases such as diabetes and cancer also increase the risk of complications after infection with Sars-CoV-2. However, the mortality rate was particularly high in patients with cardiovascular disease (10.5 percent). In hypertension alone, it was given as six percent.

Looking for the reasons

Medical professionals worldwide are trying to investigate the reasons for this statistical cluster. There are many explanatory models. Cardiovascular diseases do not play a causal role in all of them. Due to the thin data situation, the pros and cons of the individual hypotheses are difficult to weigh. Researchers therefore emphasize the importance of detailed clinical data – especially from Germany, since the age of those infected is significantly lower than in other countries. Corresponding data is currently collected in the so-called Leoss Register.

An overview of the individual explanatory models:

• Cause or simply connection? Cardiovascular diseases are not always, but often diseases of old age. In Germany alone, three out of four people in their seventies have high blood pressure. Steffen Massberg, director at the Ludwig Maximilians University in Munich and deputy chairman of the board of the German Center for Cardiovascular Research (DZHK), emphasizes that there are often other comorbidities with age. All in all, all of this could lead to these people “perhaps taking a worse infection,” said Massberg.
  In view of the data, it is important to consider: “Is it really the cardiovascular disease that causally contributes to the fact that the Covid disease is worse? Or is the effect perhaps not so specific?” The age associated with these basic diseases could possibly also play a role. In order to be able to finally answer these questions, data would still be missing, emphasizes the doctor. “This is a question that, as of today, we cannot answer with certainty because large numbers are needed to differentiate these individual influencing factors.”

• Pneumonia means top performance for the heart: Sars-CoV-2 infection is often mild. In severe cases, however, the coronavirus leads to viral pneumonia. “If the lungs are severely inflamed, the blood vessels constrict and this increases the pressure against which the heart has to pump, especially in the right part of the heart,” said lung specialist Christian Karagiannidis in an interview with the star. “People with heart problems are considered to be pre-loaded.” However, this is not a typical phenomenon of Covid-19. “We see this in all forms of pneumonia,” says Karagiannidis.
• Does Sars-CoV-2 damage the heart? At the beginning of the epidemic, Covid-19 was considered an exclusive lung disease. There is growing evidence that infection with Sars-CoV-2 not only causes pneumonia, but could also damage the heart. Around “a quarter to a fifth” of all inpatients treated develop so-called myocardial markers, says the Munich doctor Massberg.
  The myocardium is the muscle layer of the heart. If this is damaged, for example, by an infarction, enzymes contained in the heart muscle cells enter the bloodstream. These enzymes play a role in the diagnosis of heart attacks, but are also found in individual Covid patients with severe courses. There are therefore laboratory technical indications for heart muscle damage, says Massberg. “We will have to find out whether this is a specific effect of the virus or just an expression of an overall serious impairment of different organ systems.”
  Cardiac muscle damage can generally occur with all viral and bacterial infections. However, one research approach in Sars-CoV-2 is the receptor to which the virus binds in order to be absorbed into the body cells: ACE2. The abbreviation stands for “angiotensin converting enzyme 2”. In addition to the lungs, the receptor is also found in other organs, including the heart. It is currently still unclear whether the virus can directly damage the heart muscle cells in this way and, for example, trigger myocarditis, a condition known as myocarditis.

How should patients deal with these many open questions? Above all: What does this mean for the medication of blood pressure patients who take ACE inhibitors – a drug that has an influence on the complex ACE regulation of the body? These antihypertensive drugs are currently suspected of influencing the course of Covid-19 disease both positively and negatively.

Hypertension: Stopping medication poses risks

Thomas Eschenhagen, Director of the Institute for Experimental Pharmacology and Toxicology at the UKE Hamburg, warns of rash action: ACE inhibitors should “never be discontinued”. “Simply because the data situation is far too uncertain.” Steffen Massberg also emphasizes: “It is important that the underlying cardiovascular disease is treated.” The better this is treated, the better the presumably the better the course of a possible Covid 19 infection. What else should pre-stressed people take into account? “Otherwise, what applies to everyone else applies: of course, consistent compliance with the currently applicable separation and contact reduction,” says Massberg.