Managing pulmonary embolism from presentation to extended treatment

Pharmacology of Heparin and Related Drugs: An Update

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

Ultra-Low-Dose Systemic Tissue Plasminogen Activator in High-Risk Submassive Pulmonary Embolism

Risk stratification of pulmonary embolism (PE) is vital for clinical management. While low-risk and high-risk PE management are clearly defined in many societal guidelines, the management of moderate-risk, also called submassive, PE remains unsettled. There is a subgroup of patients with submassive PE that progress to the severe category despite receiving systemic anticoagulation. The role of thrombolysis in the management of submassive PE remains to be established. We share our experience with ultra-low-dose (25-mg) systemic tissue plasminogen activator in a series of 4 patients with high-risk submassive PE.

Techniques for Detection of Clinical Used Heparins

Heparins and sulfated polysaccharides have been recognized as effective clinical anticoagulants for several decades. Heparins exhibit heterogeneity depending on the sources. Meanwhile, the adverse effect in the clinical uses and the adulteration of oversulfated chondroitin sulfate (OSCS) in heparins develop additional attention to analyze the purity of heparins. This review starts with the description of the classification, anticoagulant mechanism, clinical application of heparins and focuses on the existing methods of heparin analysis and detection including traditional detection methods, as well as new methods using fluorescence or gold nanomaterials as probes. The in-depth understanding of these techniques for the analysis of heparins will lay a foundation for the further development of novel methods for the detection of heparins.

Perioperative Outcomes of Thrombectomy Patients Using Venovenous Bypass and Suction Filtration With General Anesthesia

OBJECTIVE

AngioVac (Angiodynamics, Latham, NY) is a novel drainage system that offers a less-invasive approach compared with open surgical thromboembolectomy to remove intracardiac and intravascular thrombotic and embolic material. For this study, the authors' single-center experience with patients undergoing thromboembolectomy using the AngioVac system was reviewed retrospectively to evaluate anesthetic management and postoperative complications.

DESIGN

Retrospective, observational study.

SETTING

Single institution, quaternary care hospital.

PARTICIPANTS

The study comprised 20 consecutive patients whose treatment included the AngioVac between January 2016 and November 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Twenty patients underwent AngioVac suction filtration. The mean age was 56 years, and women comprised 35% of the patient cohort. Indications for AngioVac suction filtration included deep venous thrombosis involving the inferior vena cava (n = 12 [60%]), right atrial mass/thrombus (n = 11 [55%]), right ventricular mass/thrombus (n = 3 [15%]), and pulmonary embolism(n = 2 [10%]). All patients required vasopressor support, and nine patients (45%) required blood transfusion during the procedure. There was no intraoperative death or cardiac arrest associated with the procedure. The 30-day mortality was zero, and in-hospital mortality was 5% (1/20). Significant postoperative complications occurred in 11/20 patients (55%). Postoperative left ventricular dysfunction (36% v 0%; p < 0.05), preoperative shock requiring vasopressors (36% v 0%; p < 0.05), postoperative blood transfusion (100% v 56%; p < 0.05), and having undergone recent surgery (64% v 11%; p < 0.05) were associated with increased odds of experiencing postoperative complications.

CONCLUSIONS

The rate of intraoperative complication during AngioVac suction filtration is low, but vasopressors and blood transfusions often are required. Patients at increased risk of developing postoperative complications potentially can be identified as having undergone recent surgery, experiencing preoperative shock requiring vasopressors or postoperative left ventricular dysfunction, and requiring postoperative blood transfusion.

Peptide-based fibrin-targeting probes for thrombus imaging

The development of new methods to image the onset and progression of thrombosis is an unmet need. Non-invasive molecular imaging techniques targeting specific key structures involved in the formation of thrombosis have demonstrated the ability to detect thrombus in different disease state models and in patients. Due to its high concentration in the thrombus and its essential role in thrombus formation, the detection of fibrin is an attractive strategy for identification of thrombosis. Herein we provide an overview of recent and selected fibrin-targeted probes for molecular imaging of thrombosis by magnetic resonance imaging (MRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), and optical techniques. Emphasis is placed on work that our lab has explored over the last 15 years that has resulted in the progression of the fibrin-binding PET probe [64Cu]FBP8 from preclinical studies into human trials.

An intimal sarcoma of pulmonary artery mimicking pulmonary embolism: a case report and literature review

Pulmonary artery intimal sarcoma is a highly aggressive disease, and is most often misdiagnosed as pulmonary thromboembolism (PTE) due to the similar clinical symptoms and its rarity, which leads to the use of inappropriate treatments such as prolonged anticoagulant therapy. We reported a case of pulmonary artery intimal sarcoma in a patient who was misdiagnosed as having PTE. Pathology after surgery confirmed malignant disease. We concluded that when a patient presents with mild clinical manifestations yet with strong imaging manifestations, pulmonary artery malignancy should be suspected.

ANMCO Position Paper: long-term follow-up of patients with pulmonary thromboembolism

Venous thromboembolism (VTE), including pulmonary embolism and deep venous thrombosis, is the third most common cause of cardiovascular death. The management of the acute phase of VTE has already been described in several guidelines. However, the management of the follow-up (FU) of these patients has been poorly defined. This consensus document, created by the Italian cardiologists, wants to clarify this issue using the currently available evidence in VTE. Clinical and instrumental data acquired during the acute phase of the disease are the cornerstone for planning the FU. Acquired or congenital thrombophilic disorders could be identified in apparently unprovoked VTE during the FU. In other cases, an occult cancer could be discovered after a VTE. The main targets of the post-acute management are to prevent recurrence of VTE and to identify the patients who can develop a chronic thromboembolic pulmonary hypertension. Knowledge of pathophysiology and therapeutic approaches is fundamental to decide the most appropriate long-term treatment. Moreover, prognostic stratification during the FU should be constantly updated on the basis of the new evidence acquired. Currently, the cornerstone of VTE treatment is represented by both the oral and the parenteral anticoagulation. Novel oral anticoagulants should be an interesting alternative in the long-term treatment.

Pulmonary embolism in a healthy woman using the oral contraceptives containing desogestrel

Venous thromboembolism is well known as one of the rare but serious adverse effects of combined oral contraceptives (COCs). The COCs with third and fourth generation progestogens were found to have higher risk of venous thrombosis than those with second generation progestogens. We present a case of pulmonary embolism in a 23-year-old nulligravid woman who was using COCs containing the third generation progestogen (desogestrel). At the time of presentation of the adverse effect, she had been using the COCs for 4 months. She had no additional risk factors for thrombosis such as smoking, surgery, tumor as well as genetic factors. This case demonstrates even young women in otherwise good health may be at risk of venous thromboembolism from low-dose formulations of COCs as an over-the-counter drug. We describe this case with a brief review of literatures.

Trauma-induced coagulopathy and critical bleeding: the role of plasma and platelet transfusion

Hemorrhage is responsible for 30 to 40% of all trauma-related mortality. Among adult trauma patients, 94% of hemorrhage-related deaths occur within 24 h and approximately 60% of these deaths within 3 h of hospital admission. Therefore, appropriate initial fluid resuscitation for bleeding is crucial to avoid preventable trauma-related death. In particular, the resuscitation strategy must be designed to complement prompt correction of anemia, coagulopathies, and thrombocytopenia. Conventional damage control resuscitation (DCR) of patients with severe trauma and massive hemorrhage is usually begun with rapid infusion of 1000 to 2000 mL of crystalloid fluids with subsequent transfusion of type O or uncross-matched red blood cells (RBCs) without plasma such as fresh frozen plasma (FFP) or platelets (PLTs). However, this DCR technique often leads to several adverse events such as abdominal compartment syndrome, acute respiratory distress syndrome, multiple organ failure, and dilutional coagulopathy. Simultaneous transfusion of FFP and PLTs along with the first units of RBCs while minimizing crystalloid infusion was recently recommended as a renewed DCR strategy. This aggressive RBC transfusion with FFP and PLTs is not only essential for the correction of coagulopathies and thrombocytopenia but also has the potential to ensure a good outcome in trauma patients. Additionally, it is important to maintain the resuscitation ratios of FFP/RBC and PLT/RBC. Most recently, DCR has been advocated for rapid hemorrhage control through early administration of a mixture of FFP, PLTs, and RBCs in a balanced ratio of 1:1:1.

D-Dimer Use and Pulmonary Embolism Diagnosis in Emergency Units: Why Is There Such a Difference in Pulmonary Embolism Prevalence between the United States of America and Countries Outside USA?

OBJECTIVE

Although diagnostic guidelines are similar, there is a huge difference in pulmonary embolism (PE) prevalence between the United States of America (US) and countries outside the USA (OUS) in the emergency care setting. In this study, we prospectively analyze patients' characteristics and differences in clinical care that may influence PE prevalence in different countries.

METHODS

An international multicenter prospective diagnostic study was conducted in a standard-of-care setting. Consecutive outpatients presenting to the emergency unit and suspected for PE were managed using the Wells score, STA-Liatest® D-Dimers and imaging.

RESULTS

The prevalence of PE in the study was 7.9% in low and moderate risk patients. Among the 1060 patients with low or moderate pre-test probability (PTP), PE prevalence was four times higher in OUS (10.7%) than in the US (2.5%) (P < 0.0001). The mean number of imaging procedures performed for one new PE diagnosis was 3.3 in OUS vs 17 in the US (P < 0.001). Stopping investigation in the case of negative D-dimers (DD combined) with low/moderate PTP was more frequent in OUS (92.7%) than in the US (75.7%) (P < 0.01). Moreover, the use of imaging was much higher in the US (44.4% vs 19.2% in OUS) in the case of moderate PTP combined with negative DD.

CONCLUSION

Differences between US and OUS PE prevalence in emergency setting might be explained by differences in patients' characteristics and mostly in care patterns. US physicians performed computed tomographic pulmonary angiography more often than in Europe in cases of low/moderate PTP combined with negative DD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01221805.

Pharmacology of Heparin and Related Drugs

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use. However, it is increasingly recognized that heparin has many other pharmacological properties, including but not limited to antiviral, anti-inflammatory, and antimetastatic actions. Many of these activities are independent of its anticoagulant activity, although the mechanisms of these other activities are currently less well defined. Nonetheless, heparin is being exploited for clinical uses beyond anticoagulation and developed for a wide range of clinical disorders. This article provides a "state of the art" review of our current understanding of the pharmacology of heparin and related drugs and an overview of the status of development of such drugs.

A Rare Cause of Pulmonary Embolism and Seizure in a Young Man: Antiphospholipid Syndrome

Pulmonary embolism (PE) is a complication of underlying vascular thrombosis. The causes of PE are multi-factorial, and patients with PE present with various symptoms. We herein have presented the case of a 21-year-old man who initially developed palpitation, dyspnea, and seizure. Computed tomography of the chest ultimately indicated PE, and antiphospholipid syndrome (APS) was diagnosed with clinical thrombosis events and series presence of antiphospholipid antibodies. APS commonly causes vascular thrombosis within the vascular tree; however, nonthrombotic manifestations, such as seizure, may also occur. Clinicians should be aware of such non-thrombotic manifestations of APS to avoid misdiagnosis and inappropriate management.

KEY WORDS

Antiphospholipid syndrome • Pulmonary embolism • Seizure.

Treating pulmonary embolism in Pacific Asia with direct oral anticoagulants

Pulmonary embolism (PE) is the principal preventable cause of in-hospital deaths. Prevalence of PE in Asians is uncertain but undoubtedly underestimated. Asians and Caucasians have similar non-genetic risk factors for PE, and there is mounting evidence that PE affects Asians much more commonly than previously supposed; incidence, especially among high-risk patients, may approach that in Caucasians. Furthermore, PE incidence in Asia is increasing, due to both increased ascertainment, and also population ageing and growing numbers of patients with predisposing risk factors. Despite being warranted, thromboprophylaxis for high-risk patients is not routine in Pacific Asian countries/regions. There also appears to be scope to implement venous thromboembolism (VTE) management guidelines more assiduously. Anticoagulants, primarily heparins and warfarin, have been the mainstays of VTE management for years; however, these agents have limitations that complicate routine use. The complexity of current guidelines has been another barrier to applying evidence-based recommendations in everyday practice. Updated management approaches have considerable potential to improve outcomes. New oral anticoagulants that are easier to administer, require no, or much less, monitoring or dose-adjustment and have a favourable risk/benefit profile compared with conventional modalities, may offer an alternative with the potential to simplify VTE management. However, more information is required on practical management and the occurrence and treatment of bleeding complications. Increasing recognition of the burden of PE and new therapeutic modalities are altering the VTE management landscape in Pacific Asia. Consequently, there is a need to further raise awareness and bridge gaps between the latest evidence and clinical practice.

Saddle pulmonary embolus and bronchiolitis obliterans with organizing pneumonia develop simultaneously after first cyclophosphamide, methotrexate, 5FU chemotherapy for breast cancer

A 62-year-old woman underwent a right mastectomy with axillary node dissection for a poorly differentiated ductal carcinoma. One month later, she underwent a left nephrectomy for a renal cell carcinoma. Two weeks after, she received her first cycle of cyclophosphamide, methotrexate, and 5FU (CMF) as a part of her breast cancer treatment. We describe an unusual case of non-occlusive saddle pulmonary embolus with extensive bilateral deep vein thrombosis and severe bronchiolitis obliterans with organizing pneumonia developing simultaneously after the first CMF chemotherapy for breast cancer.

Antipsychotic drug exposure and risk of pulmonary embolism: a population-based, nested case-control study

BACKGROUND

Only three observational studies investigated whether exposure to antipsychotics is associated with an increased risk of pulmonary embolism, with conflicting results. This study was therefore carried out to establish the risk of pulmonary embolism associated with antipsychotic drugs, and to ascertain the risk associated with first- and second-generation antipsychotic drugs, and with exposure to individual drugs.

METHODS

We identified 84,253 adult individuals who began antipsychotic treatment in a large Italian health care system. Cases were all cohort members who were hospitalized for non-fatal or fatal pulmonary embolism during follow-up. Up to 20 controls for each case were extracted from the study cohort using incidence density sampling and matched by age at cohort entry and gender. Each individual was classified as current, recent or past antipsychotic user. The occurrence non-fatal or fatal pulmonary embolism was the outcome of interest.

RESULTS

Compared to past use, current antipsychotic use more than double the risk of pulmonary embolism (odds ratio 2.31, 95% confidence interval 1.16 to 4.59), while recent use did not increase the risk. Both conventional and atypical antipsychotic exposure was associated with an increase in risk, and the concomitant use of both classes increased the risk of four times (odds ratio 4.21, 95% confidence interval 1.53 to 11.59).

CONCLUSIONS

Adding the results of this case-control study to a recent meta-analysis of three observational studies substantially changed the overall estimate, which now indicates that antipsychotic exposure significantly increases the risk of pulmonary embolism.