ABSTRACT
Background: Inpatients with COVID-19 have a high rate of venous thromboembolism (VTE), yet those that are most unwell have been shown to exhibit excess bleeding following thromboprophylaxis. Risk profiling of those at highest thrombotic risk may therefore improve outcomes. Aim(s): To derive and validate a risk assessment model for VTE in COVID-19 inpatients. Method(s): Electronic health records were used to assess all patients admitted for >=1 night with laboratory-confirmed COVID-19 between March 2020 and July 2021 to Barts Health NHS Trust in East London. The primary event of interest was VTE within 28 days from diagnosis. The study population was split into derivation (n = 4655) and validation sets (n = 1844). Potential predictors of VTE included demographic and lifestyle variables, clinical characteristics, and biomarkers. A logistic regression model was developed with predictors identified using least absolute shrinkage and selection operator (LASSO) methodology. Result(s): The study population comprised 6499 patients (45% women, median age 60). 394 patients (6.1%) were diagnosed with >=1 VTE event (30 DVT, 364 PE +/-DVT) within 28 days of diagnosis. D-dimer on admission was the strongest predictor for VTE. The risk of VTE was associated with increasing D-dimer up to 10 mg/L. Further rises in D-dimer above this level did not confer additional risk. Chronic cardiac disease, chronic obstructive pulmonary disease, and oxygen flow rate were also independently associated with increased risk. High peripherally measured oxygen saturations, ischaemic heart disease and supraventricular arrhythmias were associated with a reduced risk of VTE (Figure 1). The risk assessment model offered a strong discriminatory value (c-index 0.77) and achieved good calibration in both the derivation and validation set (Table 1). Conclusion(s): The proposed model was robust in predicting VTE risk in successive waves of COVID-19 infection (original, alpha and delta variants) and supports the use of the D-dimer level for guiding thromboprophylaxis. (Table Presented).
ABSTRACT
COVID-19 infection is associated with a hypercoagulable state;critically ill COVID-19 patients have a high incidence of in-hospital venous and arterial thromboembolic events (VTE and ATE). It remains unclear whether there is an increased rate of postdischarge thromboembolism or bleeding beyond the known increased risk following hospitalisation for any other acute illness, how to define any increased risk, and whether extended thromboprophylaxis is efficacious or safe. This is reflected in the variability of recommendations in existing and prior iterations of national and international guidance. We aim to examine bleeding, VTE, ATE and all-cause mortality (ACM) in cohorts who received and did not receive extended thromboprophylaxis following an inpatient admission with COVID-19. At the four hospitals comprising Barts Health NHS Trust, we offered 14 days of apixaban 2.5 mg twice a day or enoxaparin at a prophylactic weight-based dose to non-pregnant adults on discharge after an inpatient admission with PCRpositive COVID-19 infection who met the following criteria: they remained clinically unwell;bleeding and thrombotic criteria for inpatient thromboprophylaxis were met;there was an anticipated reduction in mobility on discharge and there was no alternative indication for or contra-indication to anticoagulants. We retrospectively reviewed the electronic records of all eligible patients discharged between 1st August and 31st October 2020 to audit concordance to our guideline, and to determine the incidence of major bleeding (MB) as defined by ISTH criteria within 30 days and VTE, ATE and ACM within 90 days of discharge. We calculated the IMPROVE-DD score for each patient, which has been used to stratify patients with COVID-19 for inpatient and extended thromboprophylaxis. 286 discharges were assessed (58% male;median age of 55 years). 45/286 (15.7%) of discharges received extended VTE prophylaxis. 43/45 patients received apixaban and 2/45 patients received enoxaparin. In these patients, no MB or VTE complications were reported. There was one ATE and one death, of metastatic cancer. Of these patients, 15 (33%) had an IMPROVE-DD score ≥4. The one patient with ATE had an IMPROVE-DD score ≥4. Among 241 discharges without extended thromboprophylaxis, 227 were concordant to the Trust guideline. Of the 227 patients, MB occurred in one patient (haemorrhagic stroke), VTE, ATE and death occurred in one, two and seven (3.1%) patients respectively. Eleven out of 227 (5%) of patients had an IMPROVE-DD score ≥4, of whom none had a VTE or ATE. 14 discharges met the criteria for, but were discharged without, extended thromboprophylaxis. In this group, there was zero MB, one VTE, two ATE and three deaths. There were two patients with an IMPROVE-DD score ≥4, of whom neither had a VTE or ATE. Patients discharged with extended prophylaxis were more likely to have an IMPROVE-DD score ≥4 (33% vs. 5%). To conclude, our data suggest that the risk of postdischarge thrombotic events and major bleeding after COVID-19 infection is low, irrespective of extended thromboprophylaxis. We have shown that the guideline we adopted to define patients for extended thromboprophylaxis, that was in keeping with national guidelines at that time, was less restrictive than a score-based approach to patient selection using an IMPROVE-DD ≥4. However, patients with VTE in our cohort did not have an IMPROVE-DD ≥4. This data therefore does not support a score-based approach for patient selection for thromboprophylaxis.
ABSTRACT
Content: The COVID-19 pandemic onset in March 2020 resulted in the rapid implementation of virtual clinics throughout the NHS to minimise infection transmission in hospitals. This transformation may become permanent after the pandemic, in line with the NHS Long Term Plan (2019). This envisaged the increasing use of virtual/remote (telephone and video) Attend Anywhere consultations to improve convenience for patients, enhance clinic capacity, and more productive use of consultant time. Despite these potential benefits, there is limited research into the safety, acceptability and suitability of virtual/remote clinics for patients in different clinical services. We evaluated patient preferences and feasibility for the future use of virtual/remote consultations by conducting a telephone survey of patients remotely attending' thrombosis and anticoagulation clinics at a single London NHS Trust during the COVID-19 pandemic. At the end of each telephone consultation, patients were asked two questions: (1) In the current climate of the COVID-19 pandemic, what would your preference be in terms of being seen in future clinics face to face, video or telephone?', (2) Do you have access to a smartphone or computer that you could use with video consultations in the future or can you get support from a family member/friend to do this?' Patient preferences were analysed by median age group, gender, and new/follow-up status. A total of 51 patients [23 females (45.1%) and 28 males (54.9%)] were surveyed. Median age was 65.5 years (range 23 100 years). There were 16 new and 35 follow-up patients with 42 patients attending consultant-led thrombosis clinics and 9 attending nurse/pharmacist-led anticoagulant clinics. 42 patients were seen because of venous thromboembolism (VTE), 6 because of atrial fibrillation (AF), and 3 for other conditions. 45 patients (88.2%) preferred a specific type of consultation and 6 patients (11.8%) showed no preference. 33 of 45 patients (64.7%) preferred virtual/remote consultation, whereas 12 patients (23.5%) preferred face-to-face contact. Out of the 33 patients who preferred a virtual/remote consultation, 17 (33.3%) preferred only telephone, 8 (15.7%) preferred only video, and 8 (15.7%) preferred either video or telephone. These proportions were similar in females and males, aged under and over 65, and new compared to follow-up patients. 37 patients (72.5%) had access to a smartphone or computer. Median age of patients who had access was 65.5 years (range 23-91 years), and in patients who did not have access was 76.0 years (range 29-100 years). The majority of patients preferred virtual/remote consultations for the future. Telephone consultations appeared more popular than video consultations, despite most patients having access to a smartphone or computer. The findings may be influenced by the methodology of the survey being conducted at the end of a phone consultation and during the COVID-19 pandemic. Remote/virtual thrombosis clinics seem likely to continue for many patients after the COVID pandemic. Further research is needed to identify the factors that determine individual patient preferences and the clinical implications and safety of different types of consultation.