Cause of death of pulmonary embolism: Coronavirus infection appears to increase the risk of blood clots, according to autopsy results. Researchers have surprisingly found deep venous thrombosis and pulmonary embolism in Covid-19 patients who died in Germany. Apparently, this disease can be linked to impaired blood clotting. It is still unclear which factors are responsible for this. However, preventive treatment with blood thinners could possibly make sense, say the scientists.
What can Sars-CoV-2 do in the body and what effects play a role in the particularly severe course of the disease? Gradually, researchers are now gaining insights into these questions. It has already become apparent that the pathogen can cause further damage to the patient’s body in addition to severe pneumonia: the heart can also be affected and neurological effects are possible – including paralysis. There was also clear evidence that blood clotting in corona patients could be impaired. The current study by a team of researchers from the University Medical Center Hamburg-Eppendorf now confirms this effect through the autopsy results of twelve patients who died in connection with Covid 19 disease.
For their study, they reconstructed the course of the disease, recorded comorbidities and determined the specific causes of death by analyzing various organs and tissues during the autopsy. The virological tests first made clear how heavily the virus had raged in these twelve patients: Sars CoV-2 genetic material was detected in the lungs in high concentrations in all patients examined. The virus was also found in the blood and in high concentrations in the liver, kidney or heart in about half of the deaths examined.
Thrombosis and pulmonary embolism
As the scientists report, the majority of the twelve patients had comorbidities known to be important risk factors associated with severe Covid-19 courses, including coronary heart disease or chronic obstructive pulmonary disease (COPD). However, the other findings were surprising. The autopsy revealed a previously unrecognized venous thromboembolism in seven of the twelve patients: a blood clot (thrombus) had formed in a deep-lying vein. In four patients, pulmonary embolism was also the direct cause of death, the studies showed. This means that a plug had come loose from a clot, had migrated to the lungs and had blocked a vessel there.
“In the autopsy of the first twelve deceased, we were able to demonstrate that there was an unexpectedly high rate of fatal pulmonary embolism, and more than half of the patients had thrombosis of the leg veins,” sums up co-author Jan Sperhake.
This accumulation of blood clots thus confirms the potentially important role of a coagulation disorder in Covid 19 patients. Exactly which factors are responsible for this still has to be clarified.
Nevertheless, the results already indicate possible improvement measures in the treatment of Covid-19 patients, the scientists emphasize: “We are considering whether, based on individual risk assessment, these patients should primarily be treated with a blood thinner in order to avoid thrombosis and pulmonary embolism in the future “Says co-author Dominic Wichmann. However, further investigations are a prerequisite for this. “In order to show a benefit for patients, a larger randomized study is required,” said the scientist.
More studies needed
Other scientists not involved in the study also attach great importance to these results and now see further need for investigation. “The results are in line with a number of observations from Italy, the Netherlands and Switzerland that report an unexpected increase in thrombotic and thromboembolic complications in critically ill Covid 19 patients,” says Alexandar Tzankov from the University Hospital Basel.
Michael Muders from the University Clinic Bonn writes: “Interesting and surprising for me is the high incidence of fatal pulmonary embolism that was not clinically recognized. The high rate of deep vein thrombosis, the cause of the pulmonary embolism that occurred, was also surprising. These findings suggest that Sars-CoV-2 modulates the blood coagulation system. The way in which this modulation takes place should therefore now be investigated further, ”said the doctor.
Source: University Medical Center Hamburg-Eppendorf, technical article: Annals of Internal Medicine, doi: 10.7326 / M20-2003