Grégoire Le Gal

Grégoire Le Gal
University of Ottawa · Department of Medicine

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639
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Introduction
Skills and Expertise

Publications

Publications (639)
Article
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Objective To determine the efficacy and safety of extended duration perioperative thromboprophylaxis by low molecular weight heparin when assessing disease-free survival in patients undergoing resection for colorectal cancer. Design Multicentre, open label, randomised controlled trial. Settings 12 hospitals in Quebec and Ontario, Canada, between...
Article
Pulmonary CTA is a commonly performed study and the radiologist's role is not limited to simply producing a report. The process from identifying the appropriate patients who will benefit from the study to improving performance in the radiology department requires the radiologist's involvement, expertise, and leadership. The focus of this narrative...
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Background: Neonatal hypothyroidism is often raised as a potential concern for the use of Computed Tomography Pulmonary Angiography (CTPA) in pregnant women with suspected PE. Objectives: To assess the incidence of neonatal hypothyroidism among newborns from mothers exposed to CTPA. Patients/methods: Pregnant women with clinically suspected PE...
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Although rare, pulmonary embolism (PE) remains one of the most common causes of severe maternal morbidity and mortality during pregnancy. Among pregnant women with suspected PE, the prevalence of confirmed disease is far lower than in the general population, reflecting the fear of missing the diagnosis and a low threshold to suspect PE in this sett...
Article
The risk of recurrence after discontinuation of anticoagulation for a combined oral contraceptive (COC)‐associated venous thromboembolism (VTE) is unclear. Therefore, we conducted a systematic review and meta‐analysis to estimate the incidence of recurrent VTE among women with COC‐associated VTE, unprovoked VTE and to compare the incidence of recur...
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No clinical prediction model has been specifically developed or validated to identify patients with unprovoked venous thromboembolism (VTE) who are at high risk of major bleeding during extended anticoagulation. In a prospective multinational cohort study of patients with unprovoked VTE receiving extended anticoagulation after completing ≥3 months...
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Background: The development of a core outcome set (COS), defined as an agreed minimum set of outcome domains that should be measured and reported in all trials of a specific disease, aims to increase the relevance of study findings to stakeholder groups and improve standardization. Objectives: As the first step in developing a COS for venous thr...
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Background: Venous thromboembolism (VTE) is a prevalent disease with high morbidity and mortality. VTE has well-documented physical sequelae, however the psychological and emotional impacts are seldom evaluated in randomized controlled trials. Objective: We conducted a scoping review of published qualitative studies aiming to understand the phys...
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Background Blunt abdominal solid organ injury is common and is often managed nonoperatively. Clinicians must balance risk of both hemorrhage and thrombosis. The optimal timing of pharmacologic venous thromboembolism prophylaxis (VTEp) initiation in this population is unclear. The objective was to evaluate early (< 48 h) compared to late initiation...
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Pulmonary embolism (PE) is one of the most common causes of severe morbidity and mortality during pregnancy. PE diagnosis during pregnancy remains a true challenge for all physicians, as many of the symptoms and signs associated with PE are often reported during physiological pregnancy. The fear of missing a PE during pregnancy leads a low threshol...
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Objective The diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) is a major challenge as it is a curable cause of pulmonary hypertension (PH). Ventilation/Perfusion (V/Q) lung scintigraphy is the imaging modality of choice for the screening of CTEPH. However, there is no consensus on the criteria to use for interpretation. The aim o...
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Objective To evaluate the safety and efficiency of a diagnostic algorithm for deep vein thrombosis (DVT) that uses clinical pretest probability based D-dimer thresholds to exclude DVT. Design Prospective diagnostic management study. Setting University based emergency departments or outpatient clinics in Canada. Participants Patients with symptom...
Article
Les problématiques posées par la prise en charge de la femme enceinte suspecte d’embolie pulmonaire (EP) aux urgences sont multiples. Les modifications physiologiques au cours de la grossesse majorent les sollicitations médicales pour des tableaux de douleur thoracique, de dyspnée, de malaise… En parallèle, ces manifestations aux cours de la grosse...
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Background The challenging clinical dilemma of detecting pulmonary embolism (PE) in suspected patients is encountered in a variety of healthcare settings. We hypothesized that the optimal diagnostic approach to detect these patients in terms of safety and efficiency depends on underlying PE prevalence, case mix, and physician experience, overall re...
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Importance Platelets represent a potential therapeutic target for improved clinical outcomes in patients with COVID-19. Objective To evaluate the benefits and risks of adding a P2Y12 inhibitor to anticoagulant therapy among non–critically ill patients hospitalized for COVID-19. Design, Setting, and Participants An open-label, bayesian, adaptive r...
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Cancer patients exhibit an increased risk of venous thromboembolism (VTE), with VTE being the second leading cause of morbidity and mortality in these patients. The implementation of lockdowns following the COVID-19 pandemic has resulted in decreased mobility and delayed access to care, thus further increasing the susceptibility to VTE. Cancer pati...
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Patients with cancer-associated thrombosis (CAT) are at high risk of recurrent venous thromboembolism (VTE) and major bleeding complications. Risks vary significantly between individuals based on cancer status, treatment, and other characteristics. To facilitate the evidence-based management of anticoagulant therapy in this patient population, a co...
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Background: How diagnostic strategies for suspected pulmonary embolism (PE) perform in relevant patient subgroups defined by sex, age, cancer, and previous venous thromboembolism (VTE) is unknown. Purpose: To evaluate the safety and efficiency of the Wells and revised Geneva scores combined with fixed and adapted D-dimer thresholds, as well as t...
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Background: The incidence of pulmonary embolism has been increasing, but its case-fatality rate is decreasing, suggesting a lesser severity of illness. The clinical importance of patients with pulmonary embolism isolated to the subsegmental vessels is unknown. Objective: To determine the rate of recurrent venous thromboembolism in patients with...
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Background: The long-term risk of major bleeding after discontinuing anticoagulant therapy for a first unprovoked venous thromboembolism (VTE) is uncertain. Objectives: To determine the incidence of major bleeding up to 5 years after discontinuing anticoagulation for a first unprovoked VTE. Methods: We searched MEDLINE, EMBASE, and Cochrane CE...
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Introduction: Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) were rapidly developed during the COVID-19 pandemic. There is emerging evidence of adverse hematologic effects including thrombocytopenia, for recipients of both mRNA and adenovirus-vector vaccines. We report findings in 9 patients diagnosed with thrombocyto...
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Background Although combined oral contraceptives (COC) are considered a transient risk factor for venous thromboembolism (VTE), the risk of recurrence after discontinuation of anticoagulation is unclear. Few studies have focused on the risk of recurrence in this group; studies report variable results and are limited by small sample size. The risk o...
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Introduction:The association between thrombosis (TE) and cancer has been well established. The risk for thrombosis in Multiple Myeloma (MM) is further compounded by therapy-related factors, which increase the risk for both arterial and venous TE. Lenalidomide + dexamethasone (Ld) is the most widely used backbone therapy for MM and may increase the...
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Background Advanced colorectal neoplasms (ACNs), including colorectal cancers (CRC) and high-risk adenomas (HRA), are detected in less than 20% of persons aged 50 years or older who undergo colonoscopy. We sought to derive personalized predictive models of risk of harbouring ACNs to improve colonoscopy wait times for high-risk patients and allocati...
Article
Pulmonary CTA is a ubiquitous study interpreted by radiologists with different levels of experience in a variety of practice settings. Pulmonary embolism (PE) can range from an incidental and clinically insignificant finding to a clinically significant thrombus that can be managed on an outpatient basis to a potentially fatal condition requiring im...
Article
Background: The long-term risk for major bleeding in patients receiving extended (beyond the initial 3 to 6 months) anticoagulant therapy for a first unprovoked venous thromboembolism (VTE) is uncertain. Purpose: To determine the incidence of major bleeding during extended anticoagulation of up to 5 years among patients with a first unprovoked V...
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Background The diagnosis of pulmonary embolism (PE) in pregnant women represents an ongoing challenge. As in the general population, the first step in pregnant women with suspected PE consists of assessing pre-test clinical probability (PTP). However, no dedicated clinical decision rule has been developed in this population. Objectives To propose...
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Introduction After deep vein thrombosis, up to 50% of patients develop post-thrombotic syndrome (PTS). PTS is a chronic condition that reduces quality of life (QOL). Cornerstones of PTS treatment include the use of elastic compression stockings but this treatment is usually incompletely effective and is burdensome. Venoactive drugs have been report...
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Objectives: Obesity is associated with increased risks of atrial fibrillation (AF) and venous thromboembolism (VTE) for which anticoagulation is commonly used. However, data on the efficacy and safety of oral anticoagulants in patients with morbid obesity are limited. Methods: We conducted a systematic review and meta-analysis to evaluate the ef...
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Background The long-term risk for recurrent venous thromboembolism (VTE) during extended anticoagulation for a first unprovoked VTE is uncertain. Objectives To determine the incidence of recurrent VTE during extended anticoagulation up to 5 years in patients with a first unprovoked VTE. Methods MEDLINE, EMBASE, and the Cochrane CENTRAL were searc...
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Background: Thrombosis and inflammation may contribute to morbidity and mortality among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation would improve outcomes in critically ill patients with Covid-19. Methods: In an open-label, adaptive, multiplatform, randomized clinical trial, critically...
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Background Peri-operative thromboprophylaxis guidelines offer conflicting recommendations on when to start thromboprophylaxis. As a result, there is significant variation in clinical practice which may lead to worse patient outcomes. The objective of this study was to evaluate the association between the start time of peri-operative thromboprophyla...
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We propose a methodological framework to support the development of personalized courses that improve patients’ understanding of their condition and prescribed treatment. Inspired by Intelligent Tutoring Systems (ITSs), the framework uses an eLearning ontology to express domain and learner models and to create a course. We combine the ontology with...
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Background: The International Society on Thrombosis and Haemostasis (ISTH)'s Scientific and Standardization Committee (SSC) recently proposed a definition of pulmonary embolism (PE)-related death. We aimed to evaluate the accuracy and interrater reliability of the definition in an autopsy cohort. Methods: We reviewed reports of 1,064 consecutive...
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Patients with cancer are at a high risk of symptomatic venous thromboembolism (VTE), which is a common cause of morbidity and mortality in this patient population. Increased risk of recurrent VTE and bleeding complications are two major challenges associated with therapeutic anticoagulation in these patients. Long-term therapy with low-molecular-we...
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Background The usefulness of D-dimer measurement to rule out venous thromboembolism (VTE) during pregnancy is debated. Aims We performed a systematic review and meta-analysis to investigate the safety of D-dimer to rule out acute VTE in pregnant women with suspected pulmonary embolism (PE) and/or deep vein thrombosis (DVT). Methods Two reviewers...
Article
Prompt evaluation and therapeutic intervention of suspected pulmonary embolism (PE) are of paramount importance for improvement in outcomes. We systematically reviewed outcomes in patients with suspected PE, including mortality, incidence of recurrent PE, major bleeding, intracranial hemorrhage, and postthrombotic sequelae. We searched the Cochrane...
Article
Background Diagnosis of heparin‐induced thrombocytopenia (HIT) requires pre‐test probability assessment and dedicated laboratory assays. Objective To develop a pre‐test score for HIT. Design Observational; analysis of prospectively collected data of hospitalized patients suspected with HIT (ClinicalTrials.gov NCT00748839). Setting Thirty‐one ter...
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Reliable laboratory diagnosis of heparin-induced thrombocytopenia (HIT) remains a major clinical concern. Immunoassays are highly sensitive, while confirmatory functional tests (based on heparin-dependent platelet activation) lack standardization. We evaluated the diagnostic performance of a functional flow cytometric assay (FCA) based on the detec...
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Introduction The risk of recurrent venous thromboembolism (VTE) after combined oral contraceptive (COC) use is variably reported. We assessed the long‐term risk of recurrent VTE in women on COC at the time of a first VTE, in comparison to women without COC use. Our secondary aim assessed the impact of COC use on the recurrent VTE risk in high risk...
Article
Importance: In patients with suspected pulmonary embolism (PE), overuse of diagnostic imaging is an important point of concern. Objective: To derive and validate a 4-level pretest probability rule (4-Level Pulmonary Embolism Clinical Probability Score [4PEPS]) that makes it possible to rule out PE solely on clinical criteria and optimized D-dime...
Article
Exogenous hormone therapies, such as combined oral contraceptives (COC) and hormone replacement therapy (HRT), cause blood hypercoagulability and are a risk factor for venous thromboembolism (VTE). There is controversy on how strong this “provoking” risk factor is, and how other risk factors may synergise VTE risk. We aim to review the latest liter...
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Objectives: ⁶⁸ Ga Ventilation/Perfusion V/Q PET-CT is a promising imaging tool for pulmonary embolism diagnosis. However, no study has verified whether the interpretation is reproducible between different observers. The aim of this study was to assess the interobserver agreement in the interpretation of V/Q PET-CT for the diagnosis of acute PE, and...
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Objectives Current guidelines do not recommend direct oral anticoagulants (DOACs) to treat cerebral venous thrombosis (CVT) despite their benefits over standard therapy. We performed a systematic review to summarise the published experience of DOAC therapy in CVT. Data sources MEDLINE, Embase and COCHRANE databases up to 18 November 2020. Eligibi...
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Introduction Oral anticoagulant (OAC) intervention trials have typically included clinical event outcomes. However, there is no standard list of outcomes to be used in OAC research. This study aimed to describe and classify the outcomes used in recent prospective clinical studies involving OACs. Materials and methods We searched MEDLINE, EMBASE, a...
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Background Pregnancy associated venous thromboembolism (VTE) is associated with high morbidity and mortality. Identification of risk factors of VTE may lead to improved maternal and fetal outcomes Proteinuria confers a pro-thrombotic state; however, its association with VTE) in pregnancy remains unknown. We set out to assess the association of prot...
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Thrombosis has emerged as an important complication of coronavirus disease 2019 (COVID-19), particularly among individuals with severe illness. However, the precise incidence of thrombotic events remains uncertain due to differences in study design, patient populations, outcome ascertainment, event definitions, and reporting. In an effort to overco...
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Introduction Venous thromboembolism (VTE) is a common, potentially fatal yet treatable disease. Several advances in treatment of VTE have been made over the past decades, but definition and reporting of outcomes across those studies are inconsistent. Development of an international core outcome set for clinical studies of interventions for VTE addr...
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Introduction Diagnostic testing for deep vein thrombosis (DVT) is a multi-step and time-consuming process. Testing starts with clinical pretest probability (C-PTP) assessment. A negative D-dimer in combination with low C-PTP is widely used to exclude DVT; otherwise ultrasound imaging is required. When proximal vein ultrasound is used, a repeat ultr...
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Introduction Methods for prognosis assessment and patient management in acute pulmonary embolism (PE) are much debated among physicians. We conducted an online survey to determine physician’s attitudes and barriers towards the use of prognostic models when treating patients with acute PE. Method Physicians members of the French and the European sc...
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Clinical research data elements vary across studies and this variation often impedes efforts to conduct meta‐analysis, introduces the possibility of misinterpretation, and increases the time and cost to develop studies. The use of consistent, consensus‐based data standards can alleviate these burdens to facilitate more effective global evidence syn...
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Background Improved imaging techniques have increased the incidence of subsegmental pulmonary embolism (ssPE). Indirect evidence is suggesting that ssPE may represent a more benign presentation of venous thromboembolism not necessarily requiring anticoagulant treatment. However, correctly diagnosing ssPE is challenging with reported low interobserv...
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Pulmonary embolism (PE) is a common, potentially life-threatening yet treatable condition. Prompt diagnosis and expeditious therapeutic intervention is of paramount importance for optimal patient management. Our objective was to systematically review the accuracy of D-dimer assay, compression ultrasonography (CUS), computed tomography pulmonary ang...
Article
Introduction: Coronavirus disease (COVID-19) is associated with a high incidence of thrombosis and mortality despite standard anticoagulant thromboprophylaxis. There is equipoise regarding the optimal dose of anticoagulant intervention in hospitalized patients with COVID-19 and consequently, immediate answers from high-quality randomized trials ar...
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Background Validated diagnostic algorithms are used to manage patients with suspected pulmonary embolism (PE). The recently published YEARS study proposed a simplified diagnostic strategy to reduce the use of computed tomography pulmonary angiography. Objectives To externally validate this strategy in an independent cohort. Methods We analyzed da...
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Title Comparison of the Wells score and the revised Geneva score as a tool to predict pulmonary embolism in outpatients over 65 years of age. Introduction The incidence and mortality of pulmonary embolism (PE) is high in the elderly. The Wells score (SW) and the revised Geneva score (RGS) have been validated in patient populations with a large age...
Article
Ventilation/perfusion (V/Q) SPECT has largely replaced conventional planar V/Q scan in nuclear medicine departments for pulmonary embolism (PE) diagnosis. However, the diagnostic performance of the test and its role in the diagnostic management of acute PE are still a matter of debate. The primary aim was to establish the diagnostic accuracy (sensi...