Patients with severe pneumonia associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who have higher platelet counts and high D-dimer levels may benefit from anticoagulant therapy, according to a report published in the Journal of Thrombosis and Thrombolysis.

The authors noted that recent research has suggested that for patients with coronavirus disease 2019 (COVID-19), the condition caused by SARS-CoV-2 infection, a poorer prognosis may be associated with a higher D-dimer level.

This retrospective analysis of patients treated at Tongji Hospital in Wuhan, China, included individuals with either severe COVID-19 (449 patients) or severe pneumonia considered to be unrelated to COVID-19 (104 patients). The investigators evaluated whether patients with elevated D-dimer levels could benefit from anticoagulation treatments, which were defined as either unfractionated heparin or low molecular weight heparin for 7 days or longer. Prothrombin time, platelet count, and D-dimer levels were evaluated for each patient.

The 28-day mortality rate among patients with COVID-19 was 29.8%, compared with 15.4% for patients without COVID-19 (P =.003). Compared with patients in the non-COVID-19 group, patients who had COVID-19 were older (58.4 years vs 65.1 years; P <.001) and had higher platelet counts (188 ± 98 x 109/L vs 215 ± 100 x 109/L; P =.015).

Overall, receipt of heparin did not alter the 28-day mortality within either patient group. However, for patients with COVID-19, the use of heparin was associated with lower mortality when stratifying by D-dimer level. Among patients with COVID-19 who had a D-dimer level of 3.0 mg/mL or higher, the use of heparin was significantly associated with decreased mortality (P =.017). A significant mortality difference with heparin did not appear for patients in the non-COVID-19 group when stratifying by D-dimer level.

Some notable study limitations included potential selection bias and influence of other patient therapies that were not evaluated; however, the authors felt the results still had clinical significance.

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“In conclusion, patients with severe pneumonia induced by [SARS-CoV-2] had higher platelet count than those induced by [non-SARS-CoV-2], and only the former with markedly elevated D-dimer may benefit from anticoagulant therapy mainly with LMWH,” the authors wrote. “Further prospective studies are needed to confirm these results.”

Reference

Yin S, Huang M, Li D, Tang N. Difference of coagulation features between severe pneumonia induced by SARS-CoV2 and non-SARS-CoV2 [published online April 3, 2020]. J Thromb Thrombolysis. doi: 10.1007/s11239-020-02105-8