The diagnostic management of suspected pulmonary embolism in special patient populations

Pulmonary embolism (PE) is a serious and sometimes life-threatening condition that refers to a blood clot that occludes the arteries of the lung. Despite all improvements over the past decades, diagnosing PE is still a difficult process due to the non-specific symptoms, which can frequently overlap with symptoms of other cardiopulmonary diseases. Currently recommended diagnostic strategies for suspected acute PE consist of standardized assessment of the clinical pre-test probability (CPTP) using validated clinical decision rules (CDRs) and D-dimer testing. PE is considered safely ruled out in patients with a non-high CPTP and a normal D-dimer test. Imaging tests as computed tomography pulmonary angiography (CTPA) are required in the case of a high CPTP and/or abnormal D-dimer test to confirm the diagnosis. The first part of this thesis describes the challenges of diagnosing PE in general and in specific clinically relevant patient subgroups. Moreover, this part evaluates the diagnostic performance of non-invasive diagnostic strategies for suspected PE in specific relevant patient subgroups. The second part of this thesis focuses on venous thrombotic complications in hospitalized patients with COVID-19.Financial support by the Dutch Heart Foundation for the publication of this thesis is gratefully acknowledged. Additional financial support for printing this thesis was kindly provided by Bayer Healthcare B.V., Chipsoft, Federatie van Nederlandse Trombosediensten, LEO Pharma B.V., Stago BNL B.V. and Trombosestichting Nederland.LUMC / Geneeskund

Prophylaxis and treatment of COVID-19 related venous thromboembolism

COVID-19 pneumonia has been associated with high rates of thrombo-embolic complications, mostly venous thromboembolism (VTE), which is thought to be a combination of conventional VTE and in situ immunothrombosis in the pulmonary vascular tree. The incidence of thrombotic complications is dependent on setting (intensive care unit (ICU) versus general ward) and the threshold for performing diagnostic tests (screening versus diagnostic algorithms triggered by symptoms). Since these thrombotic complications are associated with in-hospital mortality, all current guidelines and consensus papers propose pharmacological thromboprophylaxis in all hospitalized patients with COVID-19. Several trials are ongoing to study the optimal intensity of anticoagulation for this purpose. As for the management of thrombotic complications, treatment regimens from non-COVID-19 guidelines can be adapted, with choice of anticoagulant drug class dependent on the situation. Parenteral anticoagulation is preferred for patients on ICUs or with impending clinical deterioration, while oral treatment can be started in stable patients. This review describes current knowledge on incidence and pathophysiology of COVID-19 associated VTE and provides an overview of guideline recommendations on thromboprophylaxis and treatment of established VTE in COVID-19 patients.Thrombosis and Hemostasi

Challenges in the diagnostic approach of suspected pulmonary embolism in COVID-19 patients

Accumulating studies on COVID-19 patients report high incidences of thrombotic complications, but guidance on the best diagnostic approach for suspected pulmonary embolism (PE) in COVID-19 patients is lacking. Diagnosing PE in these patients is challenging as signs and symptoms of PE and COVID-19 show wide overlap, D-dimer levels are often elevated in the absence of thrombosis and computed tomography pulmonary angiography (CTPA) may be unfeasible in the case of severe renal impairment and/or hemodynamic instability. This narrative review discusses available literature and guidelines on current diagnostic algorithms for suspected PE in special patient populations, in particular COVID-19. A special focus is on reviewing the literature aimed at identifying symptoms with a high suspicion for PE and on the diagnostic performance of diagnostic algorithms for suspected PE in the setting of COVID-19. Based on available literature, the index of suspicion for PE should be high in the case of unexplained abrupt worsening of respiratory status, typical symptoms of deep-vein thrombosis and/or acute unexplained right ventricular dysfunction. Despite the lack of prospective diagnostic management studies, we propose to adhere to current diagnostic algorithms applying assessment of pretest probability and D-dimer testing as available evidence suggests that these might be considered safe. Preferably, algorithms using adjusted D-dimer thresholds are recommended as it likely improves the yield of the clinical decision rule/D-dimer combination.Cardiovascular Aspects of Radiolog

Targeted DNA sequencing to identify genetic aberrations in glioblastoma that underlie venous thromboembolism; a cohort study

Background and objectives: Patients with glioblastoma have a high risk of developing venous thromboembolism (VTE). However, the role of underlying genetic risk factors remains largely unknown. Therefore, the aim of this study was to discover whether genetic aberrations in glioblastoma associate with VTE risk.Methods: In this cohort study, all consecutive patients diagnosed with glioblastoma in two Dutch hospitals be-tween February 2017 and August 2020 were included. Targeted DNA next-generation sequencing of all glio-blastomas was performed for diagnostic purposes and included mutational status of the genes ATRX, BRAF, CIC, FUBP1, H3F3A, IDH1, IDH2, PIK3CA, PTEN and TP53 and amplification/gain or deletion of BRAF, CDKN2A, EGFR, NOTCH1 and PTEN. The primary outcome was VTE within three months before glioblastoma diagnosis until two years after. Cumulative incidences were determined using competing risk analysis adjusting for mor-tality. Univariable Cox regression analysis was performed to determine hazard ratios.Results: From 324 patients with glioblastoma, 25 were diagnosed with VTE. Patients with a CDKN2A deletion had a 12-month adjusted cumulative incidence of VTE of 12.5 % (95%CI: 7.3-19.3) compared with 5.4 % (95%CI: 2.6-9.6) in patients with CDKN2A wildtype (p = 0.020), corresponding to a HR of 2.53 (95%CI: 1.12-5.73, p = 0.026). No significant associations were found between any of the other investigated genes and VTE.Conclusion: This study suggests a potential role for CDKN2A deletion in glioblastoma-related VTE. Therefore, once independently validated, CDKN2A mutational status may be a promising predictor to identify glioblastoma patients at high risk for VTE, who may benefit from thromboprophylaxis

Risk of thrombotic complications in influenza versus COVID-19 hospitalized patients

Background: Whereas accumulating studies on patients with coronavirus disease 2019 (COVID-19) report high incidences of thrombotic complications, large studies on clinically relevant thrombosis in patients with other respiratory tract infections are lacking. How this high risk in COVID-19 patients compares to those observed in hospitalized patients with other viral pneumonias such as influenza is unknown.Objectives: To assess the incidence of venous and arterial thrombotic complications in hospitalized patients with influenza as opposed to that observed in hospitalized patients with COVID-19.Methods: This was a retrospective cohort study; we used data from Statistics Netherlands (study period: 2018) on thrombotic complications in hospitalized patients with influenza. In parallel, we assessed the cumulative incidence of thrombotic complications-adjusted for competing risk of death-in patients with COVID-19 in three Dutch hospitals (February 24 to April 26, 2020).Results: Of the 13 217 hospitalized patients with influenza, 437 (3.3%) were diagnosed with thrombotic complications, versus 66 (11%) of the 579 hospitalized patients with COVID-19. The 30-day cumulative incidence of any thrombotic complication in influenza was 11% (95% confidence interval [CI], 9.4-12) versus 25% (95% CI, 18-32) in COVID-19. For venous thrombotic (VTC) complications and arterial thrombotic complications alone, these numbers were, respectively, 3.6% (95% CI, 2.7-4.6) and 7.5% (95% CI, 6.3-8.8) in influenza versus 23% (95% CI, 16-29) and 4.4% (95% CI, 1.9-8.8) in COVID-19.Conclusions: The incidence of thrombotic complications in hospitalized patients with influenza was lower than in hospitalized patients with COVID-19. This difference was mainly driven by a high risk of VTC complications in the patients with COVID-19 admitted to the Intensive Care Unit. Remarkably, patients with influenza were more often diagnosed with arterial thrombotic complications.Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care

Diagnostic management of acute pulmonary embolism: a prediction model based on a patient data meta-analysis

AimsRisk stratification is used for decisions regarding need for imaging in patients with clinically suspected acute pulmonary embolism (PE). The aim was to develop a clinical prediction model that provides an individualized, accurate probability estimate for the presence of acute PE in patients with suspected disease based on readily available clinical items and D-dimer concentrations.Methods and resultsAn individual patient data meta-analysis was performed based on sixteen cross-sectional or prospective studies with data from 28 305 adult patients with clinically suspected PE from various clinical settings, including primary care, emergency care, hospitalized and nursing home patients. A multilevel logistic regression model was built and validated including ten a priori defined objective candidate predictors to predict objectively confirmed PE at baseline or venous thromboembolism (VTE) during follow-up of 30 to 90 days. Multiple imputation was used for missing data. Backward elimination was performed with a P-value ConclusionThe present model provides an absolute, individualized probability of PE presence in a broad population of patients with suspected PE, with very good discrimination and calibration. Its clinical utility needs to be evaluated in a prospective management or impact study.Thrombosis and Hemostasi

Diagnostic management of acute pulmonary embolism in special populations

Introduction Pulmonary embolism (PE) is a potentially life-threatening disease, making an accurate and prompt diagnosis thus very important. However, the normally used diagnostic algorithms may not be as efficient and safe in special patient populations. The diagnostic management of suspected PE in these patients is particularly challenging. Areas covered Current diagnostic strategies in patients with malignancy, elderly patients and patients with renal insufficiency are discussed in this review. A special focus is on reviewing the literature supporting the use of adjusted D-dimer cutoffs in these patient categories and the current guideline statements. Information is obtained through an extensive literature search of the following databases: PubMed, Embase, Web of Science, COCHRANE Library and Emcare (searched September 2019). Expert opinion A diagnostic strategy starting with clinical decision rules (CDRs) and D-dimer testing is clinically useful, also in these three patient categories, since it reduces the need for computed tomography pulmonary angiography (CTPA). The use of adjusted D-dimer cutoffs is preferred over a fixed cutoff as it safely improves the yield of the CDR/D-dimer combination

Diagnostic management of acute pulmonary embolism in special populations

Introduction Pulmonary embolism (PE) is a potentially life-threatening disease, making an accurate and prompt diagnosis thus very important. However, the normally used diagnostic algorithms may not be as efficient and safe in special patient populations. The diagnostic management of suspected PE in these patients is particularly challenging. Areas covered Current diagnostic strategies in patients with malignancy, elderly patients and patients with renal insufficiency are discussed in this review. A special focus is on reviewing the literature supporting the use of adjusted D-dimer cutoffs in these patient categories and the current guideline statements. Information is obtained through an extensive literature search of the following databases: PubMed, Embase, Web of Science, COCHRANE Library and Emcare (searched September 2019). Expert opinion A diagnostic strategy starting with clinical decision rules (CDRs) and D-dimer testing is clinically useful, also in these three patient categories, since it reduces the need for computed tomography pulmonary angiography (CTPA). The use of adjusted D-dimer cutoffs is preferred over a fixed cutoff as it safely improves the yield of the CDR/D-dimer combination.Thrombosis and Hemostasi

Confirmation of the high cumulative incidence of thrombotic complications in critically ill ICU patients with COVID-19: an updated analysis

Introduction: We recently reported a high cumulative incidence of thrombotic complications in critically ill patients with COVID-19 admitted to the intensive care units (ICUs) of three Dutch hospitals. In answering questions raised regarding our study, we updated our database and repeated all analyses.Methods: We re-evaluated the incidence of the composite outcome of symptomatic acute pulmonary embolism (PE), deep-vein thrombosis, ischemic stroke, myocardial infarction and/or systemic arterial embolism in all COVID-19 patients admitted to the ICUs of 2 Dutch university hospitals and 1 Dutch teaching hospital from ICU admission to death, ICU discharge or April 22nd 2020, whichever came first.Results: We studied the same 184 ICU patients as reported on previously, of whom a total of 41 died (22%) and 78 were discharged alive (43%). The median follow-up duration increased from 7 to 14 days. All patients received pharmacological thromboprophylaxis. The cumulative incidence of the composite outcome, adjusted for competing risk of death, was 49% (95% confidence interval [CI] 41-57%). The majority of thrombotic events were PE (65/75; 87%). In the competing risk model, chronic anticoagulation therapy at admission was associated with a lower risk of the composite outcome (Hazard Ratio [HR] 0.29, 95%CI 0.091-0.92). Patients diagnosed with thrombotic complications were at higher risk of all-cause death (HR 5.4; 95%CI 2.4-12). Use of therapeutic anticoagulation was not associated with all-cause death (HR 0.79, 95%CI 0.35-1.8).Conclusion: In this updated analysis, we confirm the very high cumulative incidence of thrombotic complications in critically ill patients with COVID-19 pneumonia

Incidence of thrombotic complications in critically ill ICU patients with COVID-19

Introduction: COVID-19 may predispose to both venous and arterial thromboembolism due to excessive inflammation, hypoxia, immobilisation and diffuse intravascular coagulation. Reports on the incidence of thrombotic complications are however not available.Methods: We evaluated the incidence of the composite outcome of symptomatic acute pulmonary embolism (PE), deep-vein thrombosis, ischemic stroke, myocardial infarction or systemic arterial embolism in all COVID-19 patients admitted to the ICU of 2 Dutch university hospitals and 1 Dutch teaching hospital.Results: We studied 184 ICU patients with proven COVID-19 pneumonia of whom 23 died (13%), 22 were discharged alive (12%) and 139 (76%) were still on the ICU on April 5th 2020. All patients received at least standard doses thromboprophylaxis. The cumulative incidence of the composite outcome was 31% (95%CI 20-41), of which CTPA and/or ultrasonography confirmed VTE in 27% (95%CI 17-37%) and arterial thrombotic events in 3.7% (95%CI 0-8.2%). PE was the most frequent thrombotic complication (n = 25, 81%). Age (adjusted hazard ratio (aHR) 1.05/per year, 95%CI 1.004-1.01) and coagulopathy, defined as spontaneous prolongation of the prothrombin time > 3 s or activated partial thromboplastin time > 5 s (aHR 4.1, 95%CI 1.9-9.1), were independent predictors of thrombotic complications.Conclusion: The 31% incidence of thrombotic complications in ICU patients with COVID-19 infections is remarkably high. Our findings reinforce the recommendation to strictly apply pharmacological thrombosis prophylaxis in all COVID-19 patients admitted to the ICU, and are strongly suggestive of increasing the prophylaxis towards high-prophylactic doses, even in the absence of randomized evidence