Platelet Count Rose While D-Dimer Levels Dropped as Deaths and Thrombosis Declined—An Observational Study on Anticoagulation Shift in COVID-19

Abstract

Background: High levels of D-dimer and low platelet counts are associated with poor outcome in COVID-19. As anticoagulation appeared to improve survival, hospital-wide recommendations regarding higher doses of anticoagulation was implemented 4/9/2020. Objectives: To investigate if trends in D-dimer levels and platelet counts associated with death, thrombosis, and the shift in anticoagulation. Methods: Retrospective cohort study of 429 patients with COVID-19 at Karolinska University Hospital. Information on D-dimer levels and platelet counts was obtained from laboratory databases and clinical data from medical records. Results: Thirty-day mortality and thrombosis rate was 19% and 18%, respectively. Pulmonary embolism was common; 65/83 (78%). Increased D-dimer levels the first week in hospital were significantly associated with death and thrombosis (OR 6.06; 95% Cl 2.10–17.5, and 3.11; 95% CI 1.20–8.10, respectively). If platelet count increased more than 35×109/L per day, the mortality and thrombotic risk decreased (OR 0.16; 95% CI 0.06–0.41, and OR 0.36; 95% CI 0.17–0.80). After implementation of updated hospital-wide recommendations, the daily mean significantly decreased regarding D-dimer levels while platelet counts rose; -1.93; 95% CI -1.00–2.87 mg/L FEU and 65; 95% CI 54–76 ×109/L and significant risk reductions for death and thrombosis were observed; OR 0.48; 95% CI 0.25–0.92 and 0.35; 95% CI 0.17–0.72. Conclusions: In contrast to D-dimer levels, increase of platelet count over the first week in-hospital was associated with improved survival and reduced thrombotic risk. The daily mean levels of D-dimer dropped while the platelet counts rose, coinciding with increased anticoagulation and a decline in thrombotic burden and mortality.

Anaemia and enhancement of coagulation are associated with severe COVID-19 infection

“…Only 6% of our patients were thrombocytopenic, whereas early pandemic studies have encountered low platelet counts (<150 × 10 9 /L) in 70–95% of patients with severe COVID-19 [ 1 , 6 ]. Platelet counts tend to increase during the disease course, [ 32 ], and as in ours, a Swedish study also found that anticoagulation use increases platelet counts and improves prognosis [ 33 ]. In Finland prophylactic anticoagulation is consistently applied early on, which may improve the platelet counts.…”

Meta-Analysis and Systematic Review of Coagulation Disbalances in COVID-19: 41 Studies and 17,601 Patients

“…(8,13)]. The reported hemostatic abnormalities with COVID-19 infection include increased D-dimers (DD) levels (14,15), fibrinogen levels (16,17), changes in the quantities and levels of activation of platelets (14,(18)(19)(20), elevated von Willebrand factor (VWF) [ (21,22), rev. by Becker et al (23)] and other coagulation parameters.…”

Editorial: Platelet Function in COVID-19

“…After hospital admission platelet counts often increase in COVID-19, peaking on day 8 in a large cohort (6). Interestingly, a recent study showed that increasing platelet counts over time (more than 10 x 10 9 /l/day) was associated with reduced risk of death and thrombosis compared to stable or decreasing values (7). Len et al note that autopsy studies show increased numbers of pulmonary megakaryocytes and presence of tissue megakaryocytes in hearts and brains of deceased COVID-19 patients (for references see Len et al).…”