Better outcome with D-dimer guided anticoagulant in hospitalised patients with moderate and severe COVID-19 illness

Abstract

Background: Venous thromboembolism (VTE) prophylaxis is recommended for all hospitalized COVID-19 patients in the absence of contraindications. Although D-dimer is a recognized biomarker for disease severity, there are insufficient data to recommend using this parameter to guide therapeutic decisions. Purpose: The aim of the study is to investigate whether D-dimer guided anticoagulant therapy (ACT) is associated with a better evolution in moderate and severe COVID 19 illness. Methods: We retrospectively analysed 120 consecutive patients (71 men, mean age 62.8±14 years old), hospitalised for moderate or severe COVID-19 illness. All patients were clinically examined, thoracic CT was performed, hematologic parameters were measured. Presence of VTE in patients with risk factors was excluded with doppler imaging and/or contrast thoracic CT. Patients with D-dimer ≤0.5 mg/L received prophylactic ACT (enoxaparin 40 mg daily), patients with D-dimer between 0.5 mg/L and 1 mg/L received 40 mg bid and those with D dimer ≥1mg/L were treated with full dose ACT (enoxaparin 1mg/kg bid). During hospitalization D-dimer was measured and the ACT was adapted accordingly. In all patients COVID-19 disease was managed according to current guidelines. After discharge patients were followed up 30±7 days. Prophylactic ACT was continued in patients with high thrombotic risk. Results: 76 patients (63.3%) had moderate, and 44 patients (36.6%) had severe disease. Comorbidities were present in 71.5% patients (61.5% with cardiovascular disease, 16.6% with diabetes mellitus, 16.6% with obesity, 6.6% with renal failure, 4.1% with neoplastic disease). Average D-dimer was 1.3±0.8 mg/L. D-dimer elevation>0.5 mg/L was seen in 79 patients (65.8%). D-dimer was higher in patients with severe vs moderate illness 1.5±0.9 mg/L vs 1.01±0.9 mg/l (p<0.05) and in patients with comorbidities vs patients with no comorbidities (1.2±0.8 mg/L vs 0.7±0.6 mg/L, p<0.05). During hospitalization and subsequent follow up no VTE was recorded. 10 patients (0.83%) initially on prophylactic doses were switched to full dose ACT. Haemorrhagic complications were recorded in 5 patients (4.1%) and were minor. 4 patients (3.3%) with moderate illness at admission and comorbidities, were transferred to intensive care unit (ICU) and subsequently died (two patients with severe respiratory failure, one patient with respiratory failure and myocarditis and one patient with coma after resuscitated cardiac arrest). 116 patients (96.7%) were discharged after a median hospitalization of 12±3 days and there were no complications recorded during the short term follow up. Conclusions: D-dimer guided therapy is associated with a lower incidence of TVP complications and mortality in moderate and severe hospitalized patients (0% vs 10% and 3.3% vs 20.3% respectively in literature data base) with nonsignificant haemorrhagic complications. This small observational study needs to be validated by further research.