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Platelet Count Rose While D-Dimer Levels Dropped as Deaths and Thrombosis Declined-An Observational Study on
Anna Sjöström1,2, Johanna Dehlsen Wersäll2, Anna Warnqvist3
1Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
Insights
Increased platelet counts in COVID-19 patients correlated with better survival and lower thrombosis risk, while D-dimer levels decreased after updated anticoagulation protocols were implemented. This suggests a link between these markers and outcomes in coronavirus disease 2019.
Area of Science:
- Hematology
- Infectious Diseases
- Critical Care Medicine
Background:
- High D-dimer levels and low platelet counts are linked to poor outcomes in patients with coronavirus disease 2019 (COVID-19).
- Anticoagulation therapy showed potential to improve survival rates in COVID-19 patients.
- Hospital-wide recommendations for higher doses of anticoagulation were implemented on April 9, 2020, to address these concerns.
Purpose of the Study:
- To investigate the association between trends in D-dimer levels and platelet counts with mortality and thrombosis in COVID-19 patients.
- To evaluate the impact of updated anticoagulation strategies on these hematological markers and clinical outcomes.
Main Methods:
- A retrospective cohort study was conducted involving 429 patients diagnosed with COVID-19 at Karolinska University Hospital.
- Data on D-dimer levels and platelet counts were collected from laboratory databases.
- Clinical data, including outcomes and treatment information, were extracted from electronic medical records.
Main Results:
- Thirty-day mortality and thrombosis rates were 19% and 18%, respectively, with pulmonary embolism being common (78%).
- Elevated D-dimer levels in the first hospital week significantly correlated with increased risk of death (OR: 6.06) and thrombosis (OR: 3.11).
- An increase in platelet count (>35 × 10^9/L per day) was associated with decreased mortality (OR: 0.16) and thrombosis risk (OR: 0.36).
- Following updated anticoagulation protocols, mean D-dimer levels decreased (-1.93 mg/L FEU) and platelet counts increased (65 × 10^9/L), coinciding with reduced death (OR: 0.48) and thrombosis (OR: 0.35) rates.
Conclusions:
- Increased platelet counts during the first week in hospital are associated with improved survival and reduced thrombotic risk in COVID-19 patients.
- D-dimer levels decreased, and platelet counts increased after the implementation of enhanced anticoagulation protocols.
- These changes in hematological markers coincided with a significant reduction in mortality and thrombotic events, supporting the efficacy of the updated strategy.
Background:
High levels of D-dimer and low platelet counts are associated with poor outcome in coronavirus disease 2019 (COVID-19). As anticoagulation appeared to improve survival, hospital-wide recommendations regarding higher doses of anticoagulation were implemented on April 9, 2020.
Objectives:
To investigate if trends in D-dimer levels and platelet counts were 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 rates were 19% and 18%, respectively. Pulmonary embolism was common, 65/83 (78%). Increased D-dimer levels in the first week in hospital were significantly associated with death and thrombosis (odds ratio [OR]: 6.06; 95% confidence interval [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 (fibrinogen-equivalent unit) 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.
Conclusion:
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.
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