High-thrombosis-risk coronavirus patients benefitted from early heparin treatment - Lessons learned

Soon after the coronavirus epidemic began, it was discovered that many patients developed blood clots. These would form anywhere in the body. In particular, pulmonary embolism was life-threatening for the patient. As the pandemic wave progressed, four randomised studies consistently showed that heparin treatment started at the hospital reduced mortality by 40%.

In the early stages of the epidemic, when there was no effective pharmacotherapy or vaccine for the coronavirus, HUS issued a recommendation on the use of low-molecular-weight heparin administered under the skin as early as possible to prevent formation of blood clots in patients with the highest risk of thrombosis and progression of the infection.

“We recommended that patients be given 10 days of heparin medication at home as soon as the diagnosis was confirmed, if the coronavirus disease involved fever, displayed general symptoms and led to bed rest. We also assessed that the patient did not carry a high risk of bleeding. Patients received the medicines from health care centres managing the coronavirus disease. Training material on subctaneous injections was prepared for patients and their families,” says Head Physician Riitta Lassila.

Early heparin treatment proved effective

A study assessing the so-called real-world data (RWD) on this heparin strategy was launched, which analyzed how heparin treatment started as preventive treatment affected the need for respiratory support and intensive care, the duration of hospital care, incidence of thrombosis and bleeding complications, as well as 30-day mortality in patients who had been hospitalised.

A total 1,189 patients needed hospital care due to the coronavirus disease in the HUS area during the monitoring periods of April to August 2020 and December 2020 to May 2021. Of those, 241 had used heparin as home care.

In the study, the control group was 482 patients who had not received heparin at home. They corresponded to patients who had early received heparin regarding age, gender, comorbidities, medication and laboratory tests collected during the hospital stay. The control patients also started receiving heparin in the hospital as the standard of care. The medication for those who had received heparin treatment at home continued at the hospital.

The study results show that the need for respiratory support and intensive care of patients who had already received heparin at home decreased significantly. The shorter the need for respiratory support and duration of hospitalisation, the longer the heparin treatment had continued. Mortality in the control group was almost three times higher (10.6%) than among those who received heparin treatment at home (3.7%). The incidence of venous thrombosis in both groups was approximately 5%. The individual cases of clinically relevant bleeding during the treatment period were below 5 , without differences in the number or nature of the bleeding complications between the groups.

Learning from the results to respond to future viral-infection waves

“It was essential for our recommendation that home care was carefully targeted and started early to prevent thrombosis based on the patient’s risk assessment. Two randomised studies on the heparin treatment of coronavirus patients had been reported while our study was ongoing. These did not demonstrate benefit of heparin treatment. The difference to our approach and study was that we only gave the heparin treatment to a well-defined group of patients with a high risk of thrombosis and progressing symptoms,” says Deputy Chief Physician Eeva Ruotsalainen.

“Our study is useful for possible future severe waves of viral infection. Many different viruses have unfavourable effects on blood clotting mechanisms,” says Lassila.

Link to research article: Early outpatient use of low-molecular-weight heparin benefits COVID-19 outcome in association with hospitalization - Lessons learned

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