Incidence of lower limb deep vein thrombosis in patients with COVID-19 pneumonia through different waves of SARS-CoV-2 pandemic: A multicenter prospective study.

OBJECTIVE: The aim of this study was to evaluate the incidence of deep vein thrombosis (DVT) of the lower limbs in patients hospitalized with COVID-19 pneumonia in a non-ICU setting according to the different waves of the SARS-CoV-2 pandemic. METHODS: Multicenter, prospective study of patients with COVID-19 pneumonia admitted to Internal Medicine units in Italy during the first (March-May 2020) and subsequent waves (November 2020 -April 2021) of the pandemic using a serial compression ultrasound (CUS) surveillance to detect DVT of the lower limbs. RESULTS: Three-hundred-sixty-three consecutive patients were enrolled. The pooled incidence of DVT was 8%: 13.5% in the first wave, and 4.2% in the subsequent waves (p = 0.002). The proportion of patients with early (< 4 days) detection of DVT was higher in patients during the first wave with respect to those of subsequent waves (8.1% vs 1.9%; p = 0.004). Patients enrolled in different waves had similar clinical characteristics, and thrombotic risk profile. Less patients during the first wave received intermediate/high dose anticoagulation with respect to those of the subsequent waves (40.5% vs 54.5%; p = 0.005); there was a significant difference in anticoagulant regimen and initiation of thromboprophylaxis at home (8.1% vs 25.1%; p<0.001). CONCLUSIONS: In acutely ill patients with COVID-19 pneumonia, the incidence of DVT of the lower limbs showed a 3-fold decrease during the first with respect to the subsequent waves of the pandemic. A significant increase in thromboprophylaxis initiation prior to hospitalization, and the increase of the intensity of anticoagulation during hospitalization, likely, played a relevant role to explain this observation.

Incidence of deep vein thrombosis through an ultrasound surveillance protocol in patients with COVID-19 pneumonia in non-ICU setting: A multicenter prospective study.

OBJECTIVE: The aim of this study was to assess the incidence of deep vein thrombosis (DVT) of the lower limbs, using serial compression ultrasound (CUS) surveillance, in acutely ill patients with COVID-19 pneumonia admitted to a non-ICU setting. METHODS: Multicenter, prospective study of patients with COVID-19 pneumonia admitted to Internal Medicine units. All patients were screened for DVT of the lower limbs with serial CUS. Anticoagulation was defined as: low dose (enoxaparin 20-40 mg/day or fondaparinux 1.5-2.5 mg/day); intermediate dose (enoxaparin 60-80 mg/day); high dose (enoxaparin 120-160 mg or fondaparinux 5-10 mg/day or oral anticoagulation). The primary end-point of the study was the diagnosis of DVT by CUS. RESULTS: Over a two-month period, 227 consecutive patients with moderate-severe COVID-19 pneumonia were enrolled. The incidence of DVT was 13.7% (6.2% proximal, 7.5% distal), mostly asymptomatic. All patients received anticoagulation (enoxaparin 95.6%) at the following doses: low 57.3%, intermediate 22.9%, high 19.8%. Patients with and without DVT had similar characteristics, and no difference in anticoagulant regimen was observed. DVT patients were older (mean 77±9.6 vs 71±13.1 years; p = 0.042) and had higher peak D-dimer levels (5403 vs 1723 ng/mL; p = 0.004). At ROC analysis peak D-dimer level >2000 ng/mL (AUC 0.703; 95% CI 0.572-0.834; p = 0.004) was the most accurate cut-off value able to predict DVT (RR 3.74; 95%CI 1.27-10, p = 0.016). CONCLUSIONS: The incidence of DVT in acutely ill patients with COVID-19 pneumonia is relevant. A surveillance protocol by serial CUS of the lower limbs is useful to timely identify DVT that would go otherwise largely undetected.