key: cord-0946487-o7extrw6
authors: Özhan, Abdulkerim; Bastopcu, Murat
title: Factors Associated with Positive Thrombus Findings at Ultrasonography in Covid-19 Ward Patients who Underwent Imaging for Suspected DVT Under Prophylactic Anticoagulation
date: 2022-02-23
journal: J Vasc Surg Venous Lymphat Disord
DOI: 10.1016/j.jvsv.2022.02.012
sha: c5e753fe851eec12ad9b483033fda34521933bd6
doc_id: 946487
cord_uid: o7extrw6

OBJECTIVE: The incidence of deep vein thrombosis (DVT) is increased in Covid-19 patients and its presence is associated with worse outcomes. Ultrasound (USG) examination of Covid-19 patients suspected DVT is challenging due to concerns with disease transmission, while timely initiation of therapeutic anticoagulation is essential. This study aimed to identify patient factors associated with positive thrombus findings at ultrasonography in Covid-19 ward patients who underwent imaging for suspected DVT. METHOD: Patients that did not require intensive care unit treatment, who underwent ultrasound imaging for suspected DVT between March – December 2020 were retrospectively included. Patient demographics, comorbidities, modified Well’s score, and D-Dimer results on the day of ultrasound were recorded. Parameters for a higher likelihood of a positive DVT result were determined by comparing patients with confirmed DVT at USG and patients with negative USG findings. To determine a cut-off for D-Dimer levels a ROC curve was constructed. The sensitivity and specificity of the determined high-risk factors in the prediction of positive USG results were calculated. RESULTS: A positive history for DVT (25% vs 4%, p<0.001), thrombophilia (9% vs 2%, p=0.048), immobilization (53% vs 23%, p=0.001), and a Well’s score ≥ 2 (50% vs 21%, p=0.001) were more frequent in patients with DVT. Mean D-Dimer levels were higher in patients with DVT (3871 ± 1805 vs 2075 ± 1543, p<0.001). The presence of either thrombophilia or D-Dimer > 2020 had a sensitivity of 93% and a specificity of 64%. The presence of either thrombophilia, D-Dimer > 2020, or a Well’s score ≥ 2 had a sensitivity of 100% and a specificity of 51%. CONCLUSION: Covid-19 patients with D-Dimer > 2020, a positive history for thrombophilia, and a Well’s score ≥ 2 should undergo a timely ultrasound examination. The high risk of DVT should be remembered for all hospitalized Covid-19 patients.

The novel coronavirus infection can cause severe respiratory disease and is 11 associated with significant morbidity in cases that require hospitalization. It is well established 14 History of previous DVT was declared by the patient or confirmed with hospital records, when 15 available. Thrombophilia was defined as a known coagulation abnormality (antithrombin III, 16 protein C or S deficiency, Factor V Leiden mutation, or other known diseases with abnormal Well's score ≥ 2. In the first model, multifactorial analysis revealed thrombophilia and high D-1 Dimer to be independently associated with positive DVT at USG. OR was 31 for thrombophilia, 2 and 1 for each 10 unit increase in D-Dimer. (Table 2) In the second model thrombophilia, high   3 Well's score, and high D-Dimer were associated with DVT, while DM was negatively associated 4 with DVT. OR for 28 for thrombophilia, 1 for each 10 unit increase in D-Dimer, and 4 for a 5 Well's Score ≥ 2. (Table 3) 6

To determine a cut-off for D-Dimer levels a ROC curve was constructed. Using the Youden's 7 index, a Dimer of 2020 had a sensitivity of 89% and 66% specificity with an area-under-curve of 8 0.789. (Figure 1 ) The diagnostic ability of high risk factors in selecting patients for an early 9 ultrasound was investigated. The presence of either thrombophilia or D-Dimer > 2020 had a 10 sensitivity of 93% and a specificity of 64%. (Table 4 ) The presence of either thrombophilia, D-11 Dimer > 2020, or a Well's score ≥ 2 had a sensitivity of 100% and a specificity of 51%. (Table   12 5) 13 14 Discussion 15 In patients with D-Dimer >2020, thrombophilia, or a Well's score ≥ 2, there is a high likelihood 16 of positive results with Doppler when DVT is suspected. The selection of patients for a timely 17 ultrasound using these factors may ensure accurate diagnosis and minimization of disease 18 transmission. 19 Ultrasound imaging has additional challenges in Covid-19 patients whose transfer to the imaging 20 units may cause additional transmission and additional risks to the hypoxic patient. Point of care 21 ultrasound at the bedside may be necessary with additional risks for the physician. The patient- 22 to-patient and patient-to-clinician transmission risk may defer a timely USG examination. Our USGs, with therapeutic anticoagulation started on patients whose USGs were deferred. In their 12 cohort, serum D-Dimer >4000 ng/mL had a sensitivity and specificity of 80% and 70% for DVT, 13 respectively. Well's criteria were developed to identify outpatients at risk of VTE prior to a USG examination.

The Well's score has low discriminatory accuracy for inpatients (19) and its applicability to 9 Covid-19 patients has not been robustly studied. In our cohort of Covid-19 patients, 20% of 10 patients with high Well's scores did not have DVT at USG and these patients contributed to J o u r n a l P r e -p r o o f J o u r n a l P r e -p r o o f J o u r n a l P r e -p r o o f J o u r n a l P r e -p r o o f 

Incidence of venous thromboembolism in hospitalized patients with COVID-19

procoagulant pattern of patients with COVID-19 acute respiratory distress syndrome

Venous Thromboembolism in COVID-19

Admission D-dimer levels, D-dimer trends, and outcomes in COVID-19

Systematic 18 assessment of venous thromboembolism in COVID-19 patients receiving 19 thromboprophylaxis: incidence and role of D-dimer as predictive factors

Cohort Analysis

How 12 to screen and diagnose deep venous thrombosis (DVT) in patients hospitalized for or 13 suspected of COVID-19 infection, outside the intensive care units

Utility of d-dimer 16 for diagnosis of deep vein thrombosis in coronavirus disease-19 infection

D-dimer driven deep vein thrombosis 19 prophylaxis strategy for hospitalized patients with COVID-19