Contrasting effects of urban trees on air quality: From the aerodynamic effects in streets to impacts of biogenic emissions in cities

Urban trees are often not considered in air-quality models although they can significantly impact the concentrations of pollutants. Gas and particles can deposit on leaf surfaces, lowering their concentrations, but the tree crown aerodynamic effect is antagonist, limiting the dispersion of pollutants in streets. Furthermore, trees emit Biogenic Volatile Organic Compounds (BVOCs) that react with other compounds to form ozone and secondary organic aerosols. This study aims to quantify the impacts of these three tree effects (dry deposition, aerodynamic effect and BVOC emissions) on air quality from the regional to the street scale over Paris city. Each tree effect is added in the model chain CHIMERE/MUNICH/SSH-aerosol. The tree location and characteristics are determined using the Paris tree inventory, combined with allometric equations. The air-quality simulations are performed over June and July 2022. The results show that the aerodynamic tree effect increases the concentrations of gas and particles emitted in streets, such as NOx (+4.6 % on average in streets with trees and up to +37 % for NO2). This effect increases with the tree Leaf Area Index and it is more important in streets with high traffic, suggesting to limit the planting of trees with large crowns on high-traffic streets. The effect of dry deposition of gas and particles on leaves is very limited, reducing the concentrations of O3 concentrations by -0.6 % on average and at most -2.5 %. Tree biogenic emissions largely increase the isoprene and monoterpene concentrations, bringing the simulated concentrations closer to observations. Over the two-week sensitivity analysis, biogenic emissions induce an increase of O3, organic particles and PM2.5 street concentrations by respectively +1.1, +2.4 and + 0.5 % on average over all streets. This concentration increase may reach locally +3.5, +12.3 and + 2.9 % respectively for O3, organic particles and PM2.5, suggesting to prefer the plantation of low-emitting VOC species in cities.

Human metapneumovirus infection is associated with a substantial morbidity and mortality burden in adult inpatients

Background

Human metapneumovirus (hMPV) is one of the leading respiratory viruses. This prospective observational study aimed to describe the clinical features and the outcomes of hMPV-associated lower respiratory tract infections in adult inpatients.

Methods

Consecutive adult patients admitted to one of the 31 participating centers with an acute lower respiratory tract infection and a respiratory multiplex PCR positive for hMPV were included. A primary composite end point of complicated course (hospital death and/or the need for invasive mechanical ventilation) was used.

Results

Between March 2018 and May 2019, 208 patients were included. The median age was 74 [62-84] years. Ninety-seven (47 %) patients were men, 187 (90 %) had at least one coexisting illness, and 67 (31 %) were immunocompromised. Median time between first symptoms and hospital admission was 3 [2-7] days. The two most frequent symptoms were dyspnea (86 %) and cough (85 %). The three most frequent clinical diagnoses were pneumonia (42 %), acute bronchitis (20 %) and acute exacerbation of chronic obstructive pulmonary disease (16 %). Among the 52 (25 %) patients who had a lung CT-scan, the most frequent abnormality was ground glass opacity (41 %). While over four-fifths of patients (81 %) received empirical antibiotic therapy, a bacterial coinfection was diagnosed in 61 (29 %) patients. Mixed flora (16 %) and enterobacteria (5 %) were the predominant documentations. The composite criterion of complicated course was assessable in 202 (97 %) patients, and present in 37 (18 %) of them. In the subpopulation of pneumonia patients (42 %), we observed a more complicated course in those with a bacterial coinfection (8/24, 33 %) as compared to those without (5/60, 8 %) (p = 0.02). Sixty (29 %) patients were admitted to the intensive care unit. Among them, 23 (38 %) patients required invasive mechanical ventilation. In multivariable analysis, tachycardia and alteration of consciousness were identified as risk factors for complicated course.

Conclusion

hMPV-associated lower respiratory tract infections in adult inpatients mostly involved elderly people with pre-existing conditions. Bacterial coinfection was present in nearly 30 % of the patients. The need for mechanical ventilation and/or the hospital death were observed in almost 20 % of the patients.

Safety of treating acute pulmonary embolism at home: an individual patient data meta-analysis

BACKGROUND AND AIMS

Home treatment is considered safe in acute pulmonary embolism (PE) patients selected by a validated triage tool (e.g. simplified PE severity index score or Hestia rule), but there is uncertainty regarding the applicability in underrepresented subgroups. The aim was to evaluate the safety of home treatment by performing an individual patient-level data meta-analysis.

METHODS

Ten prospective cohort studies or randomized controlled trials were identified in a systematic search, totalling 2694 PE patients treated at home (discharged within 24 h) and identified by a predefined triage tool. The 14- and 30-day incidences of all-cause mortality and adverse events (combined endpoint of recurrent venous thromboembolism, major bleeding, and/or all-cause mortality) were evaluated. The relative risk (RR) for 14- and 30-day mortalities and adverse events is calculated in subgroups using a random effects model.

RESULTS

The 14- and 30-day mortalities were 0.11% [95% confidence interval (CI) 0.0-0.24, I2 = 0) and 0.30% (95% CI 0.09-0.51, I2 = 0). The 14- and 30-day incidences of adverse events were 0.56% (95% CI 0.28-0.84, I2 = 0) and 1.2% (95% CI 0.79-1.6, I2 = 0). Cancer was associated with increased 30-day mortality [RR 4.9; 95% prediction interval (PI) 2.7-9.1; I2 = 0]. Pre-existing cardiopulmonary disease, abnormal troponin, and abnormal (N-terminal pro-)B-type natriuretic peptide [(NT-pro)BNP] at presentation were associated with an increased incidence of 14-day adverse events [RR 3.5 (95% PI 1.5-7.9, I2 = 0), 2.5 (95% PI 1.3-4.9, I2 = 0), and 3.9 (95% PI 1.6-9.8, I2 = 0), respectively], but not mortality. At 30 days, cancer, abnormal troponin, and abnormal (NT-pro)BNP were associated with an increased incidence of adverse events [RR 2.7 (95% PI 1.4-5.2, I2 = 0), 2.9 (95% PI 1.5-5.7, I2 = 0), and 3.3 (95% PI 1.6-7.1, I2 = 0), respectively].

CONCLUSIONS

The incidence of adverse events in home-treated PE patients, selected by a validated triage tool, was very low. Patients with cancer had a three- to five-fold higher incidence of adverse events and death. Patients with increased troponin or (NT-pro)BNP had a three-fold higher risk of adverse events, driven by recurrent venous thromboembolism and bleeding.

[Translation into French and republication of: "Treatment of cancer-associated venous thromboembolism in patients under palliative care"]

Many patients with cancer require palliative care at some stage and the vast majority of people followed in palliative care are cancer patients. Patients with cancer are at high risk of venous thromboembolism (VTE), and this is particularly true during the advanced palliative phase when mobility is limited or absent. Patients with cancer in palliative care are at higher bleeding risk compared to non-cancer patients. Decisions to treat VTE or withhold anticoagulation for these patients have proven to be difficult and depend largely on an individual clinician's judgment. For this reason, we have developed a consensus proposal for appropriate management of cancer-associated thromboembolism (CAT) in patients in palliative care, which is presented in this article. The proposal was informed by the recent scientific literature retrieved through a systematic literature review. In cancer patients in advanced palliative care, the benefit/risk ratio of anticoagulation seems unfavourable with a higher haemorrhagic risk than the benefit associated with prevention of CAT recurrence and, above all, in the absence of any benefit on quality of life. For this reason, we recommend that patients should be prescribed anticoagulants on a case-by-case basis. The choice of whether to treat, and with which type of treatment, should take into account anticipated life expectancy and patient preferences, as well as clinical factors such as the estimated bleeding risk, the type of VTE experienced and the time since the VTE event.

[Translation into French and republication of: "Management of cancer-associated thromboembolism in vulnerable population"]

Although all patients with cancer-associated thrombosis (CAT) have a high morbidity and mortality risk, certain groups of patients are particularly vulnerable. This may expose the patient to an increased risk of thrombotic recurrence or bleeding (or both), as the benefit-risk ratio of anticoagulant treatment may be modified. Treatment thus needs to be chosen with care. Such vulnerable groups include older patients, patients with renal impairment or thrombocytopenia, and underweight and obese patients. However, these patient groups are poorly represented in clinical trials, limiting the available data on which treatment decisions can be based. Meta-analysis of data from randomised clinical trials suggests that the relative treatment effect of direct oral factor Xa inhibitors (DXIs) and low molecular weight heparin (LMWH) with respect to major bleeding could be affected by advanced age. No evidence was obtained for a change in the relative risk-benefit profile of DXIs compared to LMWH in patients with renal impairment or of low body weight. The available, albeit limited, data do not support restricting the use of DXIs in patients with TAC on the basis of renal impairment or low body weight. In older patients, age is not itself a critical factor for choice of treatment, but frailty is such a factor. Patients over 70 years of age with CAT should undergo a systematic frailty evaluation before choosing treatment and modifiable bleeding risk factors should be addressed. In patients with renal impairment, creatine clearance should be assessed and monitored regularly thereafter. In patients with an eGFR less than 30mL/min/1.72m2, the anticoagulant treatment may need to be adapted. Similarly, platelet count should be assessed prior to treatment and monitored regularly. In patients with grade 3-4, thrombocytopenia (less than 50,000platelets/μL) treatment with a LMWH at a reduced dose should be considered. For patients with CAT and low body weight, standard anticoagulant treatment recommendations are appropriate, whereas in obese patients, apixaban may be preferred.

Acute phase determinant of post-thrombotic syndrome: A review of the literature

BACKGROUND

Post-thrombotic syndrome (PTS) is the main long-term complication of deep vein thrombosis (DVT). Several therapies are being evaluated to prevent or to treat PTS. Identifying the patients most likely to benefit from these therapies presents a significant challenge.

OBJECTIVES

The objective of this review was to identify risk factors for PTS during the acute phase of DVT.

ELIGIBILITY CRITERIA

We searched the PubMed and Cochrane databases for studies published between January 2000 and January 2021, including randomized clinical trials, meta-analyses, systematic reviews and observational studies.

RESULTS

Risk factors for PTS such as proximal location of DVT, obesity, chronic venous disease, history of DVT are associated with higher risk of PTS. On the initial ultrasound-Doppler, a high thrombotic burden appears to be a predictor of PTS. Among the evaluated biomarkers, some inflammatory markers such as ICAM-1, MMP-1 and MMP-8 appear to be associated with a higher risk of developing PTS. Coagulation disorders are not associated with risk of developing PTS. Role of endothelial biomarkers in predicting PTS has been poorly explored. Lastly, vitamin K antagonist was associated with a higher risk of developing PTS when compared to direct oral anticoagulants and low molecular weight heparin.

CONCLUSIONS

Several risk factors during the acute phase of VTE are associated with an increased risk of developing PTS. There is a high-unmet medical need to identify potential biomarkers for early detection of patients at risk of developing PTS after VTE. Inflammatory and endothelial biomarkers should be explored in larger prospective studies to identify populations that could benefit from new therapies.

[Translation into French and republication of: "Central venous catheter associated upper extremity deep vein thrombosis in cancer patients: Diagnosis and therapeutic management"]

Catheter-related thrombosis (CRT) is a relatively frequent and potentially fatal complication arising in patients with cancer who require a central catheter placement for intravenous treatment. In everyday practice, CRT remains a challenge for management; despite its frequency and its negative clinical impact, few data are available concerning diagnosis and treatment of CRT. In particular, no diagnostic studies or clinical trials have been published that included exclusively patients with cancer and a central venous catheter (CVC). For this reason, many questions regarding optimal management of CRT remain unanswered. Due to the paucity of high-grade evidence regarding CRT in cancer patients, guidelines are derived from upper extremity DVT studies for diagnosis, and from those for lower limb DVT for treatment. This article addresses the issues of diagnosis and management of CRT through a review of the available literature and makes a number of proposals based on the available evidence. In symptomatic patients, venous ultrasound is the most appropriate choice for first-line diagnostic imaging of CRT because it is noninvasive, and its diagnostic performance is high (which is not the case in asymptomatic patients). In the absence of direct comparative clinical trials, we suggest treating patients with CRT with a therapeutic dose of either a LMWH or a direct oral factor Xa inhibitor, with or without a loading dose. These anticoagulants should be given for a total of at least 3 months, including at least 1 month after catheter removal following initiation of therapy.

CT venography for the diagnosis of postpartum venous thromboembolism: a prospective multi-center cohort study

OBJECTIVES

To assess the role of CT venography (CTV) in the diagnosis of venous thromboembolism (VTE) during the postpartum period.

MATERIALS AND METHODS

This multicenter prospective cohort study was conducted between April 2016 and April 2020 in 14 university hospitals. All women referred for CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE) within the first 6 weeks postpartum were eligible. All CTPAs were performed on multidetector CT machines with the usual parameters and followed by CTV of the abdomen, pelvis, and proximal lower limbs. On-site reports were compared to expert consensus reading, and the added value of CTV was assessed for both.

RESULTS

The final study population consisted of 123 women. On-site CTPA reports mentioned PE in seven women (7/123, 5.7%), all confirmed following expert consensus reading, three involving proximal pulmonary arteries and four limited to distal arteries. Positive CTV was reported on-site in nine women, five of whom had negative and two indeterminate CTPAs, bringing the VTE detection rate to 11.4% (14/123) (95%CI: 6.4-18.4, p = 0.03). Expert consensus reading confirmed all positive on-site CTV results, but detected a periuterine vein thrombosis in an additional woman who had a negative CTPA, increasing the VTE detection rate to 12.2% (15/123) (95%CI: 7.0-19.3, p = 0.008). Follow-up at 3 months revealed no adverse events in this woman, who was left untreated. Median Dose-Length-Product was 117 mGy.cm for CTPA and 675 mGy.cm for CTPA + CTV.

CONCLUSION

Performing CTV in women suspected of postpartum PE doubles the detection of venous thromboembolism, at the cost of increased radiation exposure.

CLINICAL RELEVANCE STATEMENT

CTV can help in the decision-making process concerning curative anticoagulation in women with suspected postpartum PE, particularly those whose CTPA results are indeterminate or whose PE is limited to the subsegmental level.

KEY POINTS

Postpartum women are at risk of pulmonary embolism, and CT pulmonary angiography can give equivocal results. CT venography (CTV) positivity increased the venous thromboembolism detection rate from 5.7 to 11.4%. CTV may help clinical decision-making, especially in women with indeterminate CTPA results or subsegmental emboli.

[Translation into French and republication of: "Management of venous thromboembolic disease in patients with malignant brain tumours"]

This article addresses the management of venous thromboembolism in patients with malignant brain tumours, including both primary and secondary (metastatic) tumours. The available data on patients on venous thromboembolism recurrence and bleeding risks in patients with brain tumours is limited, since these patients have been excluded from most randomised, interventional, head-to-head, clinical trials comparing low molecular weight heparins to vitamin K antagonists or to direct oral factor Xa inhibitors. More information is available from retrospective observational studies, which however were generally small, and carried a high risk of confounding. Their findings suggest that direct factor Xa inhibitor use is associated with lower rates of intracranial haemorrhage compared with low molecular weight heparins. Overall, the safety profile of direct oral factor Xa inhibitors when used to prevent venous thromboembolism recurrence in patients with either primary or secondary brain tumours appears to be favourable. The available data are in favour of using an anticoagulant at a full therapeutic dose in patients with primary and secondary brain tumours experiencing a venous thromboembolism, although they are not yet sufficiently robust to permit recommending a direct factor Xa inhibitor over low-molecular weight heparin.

[Translation into French and republication of: "Recurrent venous thromboembolism in anticoagulated cancer patients: diagnosis and treatment"]

Patients with cancer are at significantly increased risk of venous thromboembolism (VTE), due both to the impact of malignant disease itself and to the impact of certain anticancer drugs on haemostasis. This is true both for first episode venous thromboembolism and recurrence. The diagnosis and management of VTE recurrence in patients with cancer poses particular challenges, and these are reviewed in the present article, based on a systematic review of the relevant scientific literature published over the last decade. Furthermore, it is uncertain whether diagnostic algorithms for venous thromboembolism, validated principally in untreated non-cancer patients, are also valid in anticoagulated cancer patients: the available data suggests that clinical decision rules and D-dimer testing perform less well in this clinical setting. In patients with cancer, computed tomography pulmonary angiography and venous ultrasound appear to be the most reliable diagnostic tools for diagnosis of pulmonary embolism and deep vein thrombosis respectively. Options for treatment of venous thromboembolism include low molecular weight heparins (at a therapeutic dose or an increased dose), fondaparinux or oral direct factor Xa inhibitors. The choice of treatment should take into account the nature (pulmonary embolism or VTE) and severity of the recurrent event, the associated bleeding risk, the current anticoagulant treatment (type, dose, adherence and possible drug-drug interactions) and cancer progression.

[Translation into French and republication of: "Anticoagulant treatment of cancer-associated thromboembolism"]

Venous thromboembolism (VTE) is a frequent and potentially fatal complication in patients with cancer. During the initial period after the thromboembolic event, a patient receiving anticoagulant treatment is exposed both to a risk of VTE recurrence and also to an elevated bleeding risk conferred by the treatment. For this reason, the choice of anticoagulant is critical. The choice should take into account patient-related factors (such as functional status, age, body mass index, platelet count and renal function), VTE-related factors (such as severity or site), cancer-related factors (such as activity and progression) and treatment related factors (such as drug-drug interactions), which all potentially influence bleeding risk, and patient preference. These should be evaluated carefully for each patient during a multidisciplinary team meeting. For most patients, apixaban or a low molecular-weight heparin is the most appropriate initial choice for anticoagulant treatment. Such treatment should be offered to all patients with active cancer for at least 6months. The patient and treatment should be re-evaluated regularly, and anticoagulant treatment changed when necessary. Continued anticoagulant treatment beyond 6months is justified if the cancer remains active or if the patient experienced recurrence of VTE in the first 6months. In other cases, the interest of continued anticoagulant treatment may be considered on an individual patient basis in collaboration with oncologists.

[Translation into French and republication of: "Home treatment for patients with cancer-associated venous thromboembolism"]

Patients hospitalised with acute venous thromboembolism (VTE), and notably patients with pulmonary embolism, often remain in hospital for extended periods due to the perceived risk of complications. However, several studies have shown that home treatment of selected patients is feasible and safe, with a low incidence of adverse events. This may offer clear benefits for patients' quality of life, hospital planning and cost to the health service. Nonetheless, there is a need for a VTE risk-stratification tool specifically addressing prognosis in patients with cancer. This may aid in the selection of low-risk patients with cancer and VTE who are suitable for outpatient treatment. Although several prognostic scores have been proposed, we suggest using a pragmatic clinical decision-making tool such as the Hestia criteria for selecting patients for home care in everyday clinical practice. Once patients have been discharged, it is mandatory to monitor patients regularly (we suggest after 3 days, 10 days, 1 month and 3 months, or more frequently if needed) with the involvement of a multidisciplinary team, so that appropriate and timely remedial action can be taken in case of warning signs of complications. If patients are selected carefully and monitored effectively, many patients who experience acute VTE can be cared for safely at home.

Outpatient management of cancer-associated pulmonary embolism: A post-hoc analysis from the HOME-PE trial

INTRODUCTION

Cancer-related pulmonary embolism (PE) is associated with poor prognosis. Some decision rules identifying patients eligible for home treatment categorize cancer patients at high risk of complications, precluding home treatment. We sought to assess the effectiveness and the safety of outpatient management of patients with low-risk cancer-associated PE.

METHODS

In the HOME-PE trial, hemodynamically stable patients with symptomatic PE were randomized to either triaging with Hestia criteria or sPESI score. We analyzed 3 groups of low-risk PE patients: 47 with active cancer treated at home (group 1), 691 without active cancer treated at home (group 2), and 33 with active cancer as the only sPESI criterion qualifying them for hospitalization (group 3). The main outcome was the composite of recurrent venous thromboembolism, major bleeding, and all-cause death within 30 days after randomization.

RESULTS

Patients treated at home had composite outcome rates of 4.3 % (2/47) for those with cancer vs. 1.0 % (7/691) for those without (odds ratio (OR) 4.98, 95%CI 1.15-21.49). Patients with cancer had rates of complications of 4.3 % when treated at home vs. 3.0 % (1/33) when hospitalized (OR 1.19, 95%CI 0.15-9.47). In multivariable analysis, active cancer was associated with an increased risk of complications for patients treated at home (OR 7.95; 95%CI 1.48-42.82). For patients with active cancer, home treatment was not associated with the primary outcome (OR 1.19, 95%CI 0.15-9.74).

CONCLUSIONS

Among patients treated at home, active cancer was a risk factor for complications, but among patients with active cancer, home treatment was not associated with adverse outcomes.

High and intermediate risk pulmonary embolism in the ICU

Pulmonary embolism (PE) is a common and important medical emergency, encountered by clinicians across all acute care specialties. PE is a relatively uncommon cause of direct admission to the intensive care unit (ICU), but these patients are at high risk of death. More commonly, patients admitted to ICU develop PE as a complication of an unrelated acute illness. This paper reviews the epidemiology, diagnosis, risk stratification, and particularly the management of PE from a critical care perspective. Issues around prevention, anticoagulation, fibrinolysis, catheter-based techniques, surgical embolectomy, and extracorporeal support are discussed.

VEGF-A plasma levels are associated with impaired DLCO and radiological sequelae in long COVID patients

BACKGROUND

Long COVID, also known as post-acute sequelae of COVID-19 (PASC), is characterized by persistent clinical symptoms following COVID-19.

OBJECTIVE

To correlate biomarkers of endothelial dysfunction with persistent clinical symptoms and pulmonary function defects at distance from COVID-19.

METHODS

Consecutive patients with long COVID-19 suspicion were enrolled. A panel of endothelial biomarkers was measured in each patient during clinical evaluation and pulmonary function test (PFT).

RESULTS

The study included 137 PASC patients, mostly male (68%), with a median age of 55 years. A total of 194 PFTs were performed between months 3 and 24 after an episode of SARS-CoV-2 infection. We compared biomarkers evaluated in PASC patients with 20 healthy volunteers (HVs) and acute hospitalized COVID-19 patients (n = 88). The study found that angiogenesis-related biomarkers and von Willebrand factor (VWF) levels were increased in PASC patients compared to HVs without increased inflammatory or platelet activation markers. Moreover, VEGF-A and VWF were associated with persistent lung CT scan lesions and impaired diffusing capacity of the lungs for carbon monoxide (DLCO) measurement. By employing a Cox proportional hazards model adjusted for age, sex, and body mass index, we further confirmed the accuracy of VEGF-A and VWF. Following adjustment, VEGF-A emerged as the most significant predictive factor associated with persistent lung CT scan lesions and impaired DLCO measurement.

CONCLUSION

VEGF-A is a relevant predictive factor for DLCO impairment and radiological sequelae in PASC. Beyond being a biomarker, we hypothesize that the persistence of angiogenic disorders may contribute to long COVID symptoms.

Risk factors for thromboembolic events in patients hospitalized for COVID-19 pneumonia in a general ward and requiring treatment with oxygen

PURPOSE

To assess risk factors for arterial and venous thromboses (AVT) in patients hospitalized in general wards for COVID-19 pneumonia and requiring oxygen therapy.

METHODS

Our study was based on three randomized studies conducted as part of the CORIMUNO-19 platform in France between 27 March and 26 April 2020. Adult inpatients with COVID-19 pneumonia requiring at least 3 l/min of oxygen but not ventilation were randomized to receive standard care alone or standard care plus biologics. Patients were followed up for 3 months, and adverse events were documented. Risk factor for AVT and bleeding was identified by analyzing clinical, laboratory, and treatment data at baseline among the 315 patients with complete datasets. A Fine and Gray model was used to take account of competing events.

RESULTS

During the 3-month follow-up period, 39 AVT occurred in 38 (10%) of the 388 patients: 26 deep vein thromboses and/or pulmonary embolisms in 25 (6%) patients, and 14 arterial thrombotic events in 13 (3%) patients. A history of diabetes at inclusion [sHR (95% CI) = 2.65 (1.19-5.91), P = .017] and the C-reactive protein (CRP) level (sHR = 1 [1-1.01], P = .049) were significantly associated with an elevated risk of thrombosis. Obesity was not associated with a higher risk of thrombosis (sHR = 1.01 [0.4-2.57], P = .98). The CRP level and diabetes were not risk factors for hemorrhage.

CONCLUSION

Among patients hospitalized in general wards for COVID-19 pneumonia during the first wave of the epidemic, diabetes (but not obesity) and a high CRP level were risk factors for AVT. The use of higher doses of anticoagulant in these high-risk patients could be considered.

A systematic review and meta-analysis of the incidence of post-thrombotic syndrome, recurrent thromboembolism, and bleeding after upper extremity vein thrombosis

BACKGROUND

Data on complications after upper extremity vein thrombosis (UEVT) are limited and heterogeneous.

METHODS

The aim of the present study was to evaluate the pooled proportions of venous thromboembolism (VTE) recurrence, bleeding, and post-thrombotic syndrome (PTS) in patients with UEVT. A systematic literature review was conducted of PubMed, Embase, and the Cochrane Library databases from January 2000 to April 2023 in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. All studies included patients with UEVT and were published in English. Meta-analyses of VTE recurrence, bleeding, and of PTS after UEVT were performed to compute pooled estimates and associated 95% confidence intervals (CIs). Subgroup analyses of cancer-associated UEVT and catheter-associated venous thrombosis were conducted. Patients with Paget-Schroetter syndrome or effort thrombosis were excluded.

RESULTS

A total of 55 studies with 15,694 patients were included. The pooled proportions for VTE recurrence, major bleeding, and PTS were 4.8% (95% CI, 3.8%-6.2%), 3.0% (95% CI, 2.2%-4.0%), and 23.8% (95% CI, 17.0%-32.3%), respectively. The pooled proportion of VTE recurrence was 2.7% (95% CI, 1.6%-4.6%) for patients treated with direct oral anticoagulants (DOACs), 1.7% (95% CI, 0.8%-3.7%) for patients treated with low-molecular-weight heparin (LMWH), and 4.4% (95% CI, 1.5%-11.8%) for vitamin K antagonists (VKAs; P = .36). The pooled proportion was 6.3% (95% CI, 4.3%-9.1%) for cancer patients compared with 3.1% (95% CI, 2.1%-4.6%) for patients without cancer (P = .01). The pooled proportion of major bleeding for patients treated with DOACs, LMWH, and VKAs, was 2.1% (95% CI, 0.9%-5.1%), 3.2% (95% CI, 1.4%-7.2%), and 3.4% (95% CI, 1.4%-8.4%), respectively (P = .72). The pooled proportion of PTS for patients treated with DOACs, LMWH, and VKAs was 11.8% (95% CI, 6.5%-20.6%), 27.9% (95% CI, 20.9%-36.2%), and 24.5% (95% CI, 17.6%-33.1%), respectively (P = .02).

CONCLUSIONS

The results from this study suggest that UEVT is associated with significant rates of PTS and VTE recurrence. Treatment with DOACs might be associated with lower PTS rates than treatment with other anticoagulants.

Recurrent venous thromboembolism in anticoagulated cancer patients: Diagnosis and treatment

Patients with cancer are at significantly increased risk of venous thromboembolism (VTE), due both to the impact of malignant disease itself and to the impact of certain anticancer drugs on haemostasis. This is true both for first episode venous thromboembolism and recurrence. The diagnosis and management of VTE recurrence in patients with cancer poses particular challenges, and these are reviewed in the present article, based on a systematic review of the relevant scientific literature published over the last decade. Furthermore, it is uncertain whether diagnostic algorithms for venous thromboembolism, validated principally in untreated non-cancer patients, are also valid in anticoagulated cancer patients: the available data suggests that clinical decision rules and D-dimer testing perform less well in this clinical setting. In patients with cancer, computed tomography pulmonary angiography and venous ultrasound appear to be the most reliable diagnostic tools for diagnosis of pulmonary embolism and deep vein thrombosis respectively. Options for treatment of venous thromboembolism include low molecular weight heparins (at a therapeutic dose or an increased dose), fondaparinux or oral direct factor Xa inhibitors. The choice of treatment should take into account the nature (pulmonary embolism or VTE) and severity of the recurrent event, the associated bleeding risk, the current anticoagulant treatment (type, dose, adherence and possible drug-drug interactions) and cancer progression.

Obesity as a Predictor for Pulmonary Embolism and Performance of the Age-Adjusted D-Dimer Strategy in Obese Patients with Suspected Pulmonary Embolism

INTRODUCTION

 Obesity is a risk factor for venous thromboembolism, but studies evaluating its association with pulmonary embolism (PE) in patients with suspected PE are lacking.

OBJECTIVES

 To evaluate whether body mass index (BMI) and obesity (i.e., BMI ≥30 kg/m2) are associated with confirmed PE in patients with suspected PE and to assess the efficiency and safety of the age-adjusted D-dimer strategy in obese patients.

METHODS

 We conducted a secondary analysis of a multinational, prospective study, in which patients with suspected PE were managed according to the age-adjusted D-dimer strategy and followed for 3 months. Outcomes were objectively confirmed PE at initial presentation, and efficiency and failure rate of the diagnostic strategy. Associations between BMI and obesity, and PE were examined using a log-binomial model that was adjusted for clinical probability and hypoxia.

RESULTS

 We included 1,593 patients (median age: 59 years; 56% women; 22% obese). BMI and obesity were not associated with confirmed PE. The use of the age-adjusted instead of the conventional D-dimer cut-off increased the proportion of obese patients in whom PE was considered ruled out without imaging from 28 to 38%. The 3-month failure rate in obese patients who were left untreated based on a negative age-adjusted D-dimer cut-off test was 0.0% (95% confidence interval: 0.0-2.9%).

CONCLUSION

 BMI on a continuous linear scale and obesity were not predictors of confirmed PE among patients presenting with a clinical suspicion of PE. The age-adjusted D-dimer strategy appeared safe in ruling out PE in obese patients with suspected PE.

Management of cancer-associated thromboembolism in vulnerable population

Although all patients with cancer-associated thrombosis (CAT) have a high morbidity and mortality risk, certain groups of patients are particularly vulnerable. This may expose the patient to an increased risk of thrombotic recurrence or bleeding (or both), as the benefit-risk ratio of anticoagulant treatment may be modified. Treatment thus needs to be chosen with care. Such vulnerable groups include older patients, patients with renal impairment or thrombocytopenia, and underweight and obese patients. However, these patient groups are poorly represented in clinical trials, limiting the available data, on which treatment decisions can be based. Meta-analysis of data from randomised clinical trials suggests that the relative treatment effect of direct oral factor Xa inhibitors (DXIs) and low molecular weight heparin (LMWH) with respect to major bleeding could be affected by advanced age. No evidence was obtained for a change in the relative risk-benefit profile of DXIs compared to LMWH in patients with renal impairment or of low body weight. The available, albeit limited, data do not support restricting the use of DXIs in patients with CAT on the basis of renal impairment or low body weight. In older patients, age is not itself a critical factor for choice of treatment, but frailty is such a factor. Patients over 70 years of age with CAT should undergo a systematic frailty evaluation before choosing treatment and modifiable bleeding risk factors should be addressed. In patients with renal impairment, creatine clearance should be assessed and monitored regularly thereafter. In patients with an eGFR<30mL/min/1.72m2, the anticoagulant treatment may need to be adapted. Similarly, platelet count should be assessed prior to treatment and monitored regularly. In patients with grade 3-4, thrombocytopenia (<50,000 platelets/μL) treatment with a LMWH at a reduced dose should be considered. For patients with CAT and low body weight, standard anticoagulant treatment recommendations are appropriate, whereas in obese patients, apixaban may be preferred.

Anticoagulant treatment of cancer-associated thromboembolism

Venous thromboembolism (VTE) is a frequent and potentially fatal complication in patients with cancer. During the initial period after the thromboembolic event, a patient receiving anticoagulant treatment is exposed both to a risk of VTE recurrence and also to an elevated bleeding risk conferred by the treatment. For this reason, the choice of anticoagulant is critical. The choice should take into account patient-related factors (such as functional status, age, body mass index, platelet count and renal function), VTE-related factors (such as severity or site), cancer-related factors (such as activity and progression) and treatment-related factors (such as drug-drug interactions), which all potentially influence bleeding risk, and patient preference. These should be evaluated carefully for each patient during a multidisciplinary team meeting. For most patients, apixaban or a low molecular-weight heparin is the most appropriate initial choice for anticoagulant treatment. Such treatment should be offered to all patients with active cancer for at least six months. The patient and treatment should be re-evaluated regularly and anticoagulant treatment changed when necessary. Continued anticoagulant treatment beyond six months is justified if the cancer remains active or if the patient experienced recurrence of VTE in the first six months. In other cases, the interest of continued anticoagulant treatment may be considered on an individual patient basis in collaboration with oncologists.

Treatment of cancer-associated venous thromboembolism in patients under palliative care

Many patients with cancer require palliative care at some stage and the vast majority of people followed in palliative care are cancer patients. Patients with cancer are at high risk of venous thromboembolism (VTE), and this is particularly true during the advanced palliative phase when mobility is limited or absent. Patients with cancer in palliative cancer are at higher bleeding risk compared to non-cancer patients. Decisions to treat VTE or withhold anticoagulation for these patients have proven to be difficult and depend largely on an individual clinician's judgment. For this reason, we have developed a consensus proposal for appropriate management of cancer-associated thromboembolism (CAT) in patients in palliative care, which is presented in this article. The proposal was informed by the recent scientific literature retrieved through a systematic literature review. In cancer patients in advanced palliative care, the benefit-risk ratio of anticoagulation seems unfavourable with a higher haemorrhagic risk than the benefit associated with prevention of CAT recurrence and, above all, in the absence of any benefit on quality of life. For this reason, we recommend that patients should be prescribed anticoagulants on a case-by-case basis. The choice of whether to treat, and with which type of treatment, should take into account anticipated life expectancy and patient preferences, as well as clinical factors such as the estimated bleeding risk, the type of VTE experienced and the time since the VTE event.

Cancer-related arterial thromboembolic events

Cancer is associated with a hypercoagulable state and is a well-known independent risk factor for venous thromboembolism, whereas the association between cancer and arterial thromboembolism is less well established. Arterial thromboembolism, primarily defined as myocardial infarction or stroke is significantly more frequent in patients with cancer, independently of vascular risk factors and associated with a three-fold increase in the risk of mortality. Patients with brain cancer, lung cancer, colorectal cancer and pancreatic cancer have the highest relative risk of developing arterial thromboembolism. Antithrombotic treatments should be used with caution due to the increased risk of haemorrhage, as specified in current practice guidelines.