Recent developments in the diagnosis and treatment of pulmonary embolism

Pulmonary arteries segmentation from CT images using PA-Net with attention module and contour loss

BACKGROUND

Pulmonary embolism is a kind of cardiovascular disease that threatens human life and health. Since pulmonary embolism exists in the pulmonary artery, improving the segmentation accuracy of pulmonary artery is the key to the diagnosis of pulmonary embolism. Traditional medical image segmentation methods have limited effectiveness in pulmonary artery segmentation. In recent years, deep learning methods have been gradually adopted to solve complex problems in the field of medical image segmentation.

PURPOSE

Due to the irregular shape of the pulmonary artery and the adjacent-complex tissues, the accuracy of the existing pulmonary artery segmentation methods based on deep learning needs to be improved. Therefore, the purpose of this paper is to develop a segmentation network, which can obtain higher segmentation accuracy and further improve the diagnosis effect.

METHODS

In this study, the pulmonary artery segmentation performance from the network model and loss function is improved, proposing a pulmonary artery segmentation network (PA-Net) to segment the pulmonary artery region from 2D CT images. Reverse Attention and edge attention are used to enhance the expression ability of the boundary. In addition, to better use feature information, the channel attention module is introduced in the decoder to highlight the important channel features and suppress the unimportant channels. Due to blurred boundaries, pixels near the boundaries of the pulmonary artery may be difficult to segment. Therefore, a new contour loss function based on the active contour model is proposed in this study to segment the target region by assigning dynamic weights to false positive and false negative regions and accurately predict the boundary structure.

RESULTS

The experimental results show that the segmentation accuracy of this proposed method is significantly improved in comparison with state-of-the-art segmentation methods, and the Dice coefficient is 0.938 ± 0.035, which is also confirmed from the 3D reconstruction results.

CONCLUSIONS

Our proposed method can accurately segment pulmonary artery structure. This new development will provide the possibility for further rapid diagnosis of pulmonary artery diseases such as pulmonary embolism. Code is available at https://github.com/Yuanyan19/PA-Net.

Neurological Consequences of Pulmonary Emboli in COVID-19 Patients: A Study of Incidence and Outcomes in the Kingdom of Saudi Arabia

Pulmonary embolism (PE) is a significant consequence that is becoming more common in COVID-19 patients. The current study sought to determine the prevalence and risk factors for PE in a study population of COVID-19 patients, as well as the relationship between PE and neurological sequelae. The research also sought to analyze the consistency of neurological examination and imaging techniques in detecting neurological problems. The research comprised a total of 63 individuals with COVID-19. The incidence of PE in the study group was 9.5% for smokers, 23.8% for obese patients, 33.3% for hypertensive patients, and 19% for diabetic patients, according to the findings. After adjusting for possible confounders such as age, gender, BMI, smoking, hypertension, and diabetes, a logistic regression analysis indicated that the probabilities of having neurological complications were 3.5 times greater in individuals who had PE. In conclusion, the present study highlights the high incidence of PE among patients with COVID-19 and the association between PE and neurological complications. The study also emphasizes the importance of a thorough neurological examination and imaging studies in the detection of neurological complications in patients with PE.

A visualized pulmonary arterial thrombus by using a modified echocardiographic view in an intermediate-risk acute pulmonary embolism patient: A case report

Acute pulmonary embolism (APE) is a life‐threatening disease with nonspecific clinical signs and symptoms. Rapid and accurate diagnosis is crucial for the clinical management of patients with acute pulmonary embolism. A recommended echocardiography view may be of further help in the diagnosis and evaluation of the change in thrombosis and treatment. We reported a case of a 74‐year‐old man with a 12‐day history of decreased exercise capacity and dyspnea. The patient was diagnosed with intermediate‐risk APE as several pulmonary emboli in pulmonary artery were seen in multidetector computed tomographic pulmonary angiography with normal blood pressure and echocardiographic right ventricular overload. And we found a pulmonary artery clot in the right pulmonary artery through transthoracic echocardiography. After 11‐days anticoagulation, the patient underwent a reassessment, showed a decrease in RV diameter and pulmonary artery thrombus. This case highlights the significant role that echocardiography played in a patient who presented pulmonary embolism with a stable hemodynamic situation and normal blood pressure. The modified echocardiographic view could provide correct diagnosis by identifying the clot size and location visually. Knowledge of the echocardiography results of APE would aid the diagnosis.

Massive Pulmonary Emboli in Klinefelter Syndrome: A Rare Case Report

Introduction

Klinefelter syndrome (KS) is a genetic disorder that affects men. An augmented incidence of the thromboembolic event described in patients with KS.

Case Presentation

A 34-year-old male identified with a definitive diagnosis of KS was hospitalized to our cardiac surgery center through the emergency with chief complaints of acute chest pain and dyspnea. Saddle pulmonary thromboembolism was established from chest Computed Tomography Angiography (CTA). The patient's symptoms resolved after embolectomy via surgery.

Conclusions

There is a tendency for hypercoagulability in KS. This tendency is because of hormonal discrepancy and hereditary thrombophilic factors. So, patients with KS and past medical history of venous thromboembolism necessitate constant oral anticoagulation therapy.

Optimal management of hormonal contraceptives after an episode of venous thromboembolism

Optimal management of hormonal contraception in patients with venous thromboembolism (VTE) requires an individualized approach considering its potential benefits and complications during and after anticoagulant treatment. Potential benefits include prevention of pregnancy and mitigation of menstrual bleeding that is often worsened after start of anticoagulation therapy. Current evidence suggests that patients may opt for a continuation of (all forms of) hormonal contraception during anticoagulant treatment, provided that they are adequately informed by the treating physicians. Combined oral contraceptives should be stopped before anticoagulant therapy may be discontinued, preferably after the second last menstrual cycle of the intended anticoagulant treatment period. If hormonal contraceptive treatment needs to be initiated in patients with a history of VTE, oral prostagen-only therapy or intra-uterine devices are to be preferred: this may be independent of the anticoagulation status and in light of a negligible risk of (recurrent) VTE associated with their use.

The Predictive Value of Thromboelastogram in the Evaluation of Patients with Suspected Acute Venous Thromboembolism

INTRODUCTION

The objective of this prospective study was to examine whether thromboelastogram (TEG) can predict the presence of venous thromboembolism (VTE) in patients who arrive at the emergency room with signs/symptoms that raise the suspicion of acute VTE.

METHODS

Every patient was tested for D-dimer and all TEG parameters, including: reaction time, clot time formation, alpha-angle, maximal amplitude, clot viscoelasticity, coagulation index, and clot lysis at 30 min. For categorical variables, χ2 or the Fisher exact test were used, and for continuous variables the t test or other non-parametric tests were used.

RESULTS

During 2016, a total of 109 patients were enrolled with a median age of 55.7 (21-89) years. Eighteen patients were diagnosed with VTE. Analyzing the different TEG parameters, both as continuous and categorical variables, did not reveal a statistically significant difference between VTE-positive and VTE-negative patients. Combining different TEG parameters or dividing the cohort according to gender, clinical suspicion of VTE (Well's criteria), or different levels of D-dimer did not change the results of the analysis.

CONCLUSION

The current study could not demonstrate a significant value of any TEG parameter as a predictor of VTE among patients who came to the emergency room with signs/symptoms that raise the suspicion of VTE.

Diagnosis of pulmonary embolism: Following the evidence from suspicion to certainty

Accurate, timely and cost-effective identification of pulmonary embolism remains a diagnostic challenge. This article reviews the pulmonary embolism diagnostic process with a focus on the best practice advice from the American College of Physicians. Benefits and risks of each diagnostic step are discussed. Emerging diagnostic tools, not included in the algorithm, are briefly reviewed.

Non-vitamin K antagonist oral anticoagulants for pulmonary embolism: who, where and for how long?

INTRODUCTION

Acute pulmonary embolism (PE) is a relatively common cardiopulmonary emergency that is a major cause of hospitalization and morbidity and is the primary cause of mortality associated with venous thromboembolism (VTE). During the last decade, one of the biggest changes in the management of PE has been the approval of four non-vitamin K antagonist oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban and rivaroxaban) for the treatment of PE and deep vein thrombosis and secondary prevention of VTE. Areas covered: This article reviews the evolving management of PE in the NOAC era and addresses three fundamental questions: who should receive NOACs over conventional heparin/vitamin K antagonist regimens for the treatment of acute PE; should patients be treated as inpatients or outpatients; and how long should patients be treated to reduce the risk of recurrence? Expert commentary: The management of PE is changing. NOACs provide new anticoagulant treatment options for patients with PE, based on Phase III clinical study results. The consistent efficacy and safety profile of NOACs across many PE patient subgroups, including the elderly, fragile patients, those with active cancer and high-risk (right ventricular dysfunction) patients, suggests NOAC use will increase among these patients.

External validation of the VTE-BLEED score for predicting major bleeding in stable anticoagulated patients with venous thromboembolism

One of the main determinants of establishing the optimal treatment duration of patients with venous thromboembolism (VTE) is the risk of major bleeding during long-term anticoagulant therapy. The 6-variable VTE-BLEED score was recently developed to enable estimation of this bleeding risk. This study aimed at externally validating VTE-BLEED. This was a post-hoc study of the randomised, double-blind, double-dummy, Hokusai-VTE study that compared edoxaban versus warfarin for treatment of VTE. VTE-BLEED was calculated in all 8,240 study patients. The numbers of adjudicated major bleeding events during ‘stable anticoagulation’, i. e. occurring after day 30, in patients with low (total score <2 points) and high risk of bleeding (total score ≥2 points) were compared for the overall study population, patients randomised to edoxaban or warfarin, and for important patient subcategories. During ‘stable’ anticoagulation, major bleeding occurred in 1.02% (40/3,903) and 0.82% (32/3,899) of patients treated with warfarin and edoxaban, respectively. For the overall study population, the risks of bleeding in the low and high risk groups were 0.51% and 2.03%, respectively, for an odds ratio (OR) of 4.04 (95% confidence interval [CI]: 2.51–6.48). ORs were 5.04 (95%CI: 2.62–9.69) and 3.09 (95%CI: 1.54–6.22) for warfarin and edoxaban, respectively. VTE-BLEED was consistently able to identify patients at a 2.5- to 11-fold higher bleeding risk across all the predefined subcategories, as well as for the treatment period between day 30 to day 180, and beyond day 180. In conclusion, patients identified as high risk by VTE-BLEED had a four-fold increased risk of bleeding during the chronic phase of treatment.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Management of incidental pulmonary embolism

Incidental pulmonary embolism (PE) is a frequent finding on routine computed tomography (CT) scans of the chest, occurring in 1.1% of coronary CT scans and 3.6% of oncological CT scans. Despite this high frequency, optimal management of incidental PE has not been addressed in clinical trials and remains the subject of debate. Although these CT scans have not been performed with a dedicated PE protocol and have suboptimal contrast enhancement, diagnosis of incidental PE has been shown to be accurate up to the segmental and subsegmental arteries. The embolic load in incidental PE is lower than that in symptomatic PE. Even so, observational studies suggest that the natural course of incidental PE is similar to that of symptomatic PE with regard to the risk of recurrent venous thrombotic disease and mortality. Interestingly, the increased use of more advanced CT technology has coincided with an increase in the rate of incidental subsegmental PE, as is the case for symptomatic subsegmental PE. Although clinical trials are lacking, and observational data are limited to cancer-associated incidental PE, the consensus is that the management of incidental PE is identical to that of symptomatic PE, including the choice of optimal drug class, outpatient treatment and total duration of treatment.

Is Routine Thromboprophylaxis Needed in Korean Patients Undergoing Unicompartmental Knee Arthroplasty?

This study was undertaken to determine the prevalence and the natural course of venous thromboembolism (VTE) without thromboprophylaxis to ascertain whether routine thromboprophylaxis is necessary following unicompartmental knee arthroplasty (UKA) in Korean patients. The medical records and multidetector row computed tomography (MDCT) imaging of the consecutive 77 UKAs in 70 patients were reviewed. In all patients, MDCTs were undertaken preoperatively and at 1-week after surgery, and VTE symptoms were evaluated. At postoperative 6-months, follow-up MDCTs were undertaken in all patients in whom VTEs were newly detected after surgery. VTE lesions were newly detected in 18 (26%) of the 70 patients. However, none of the patients complained of VTE-related symptoms and MDCT demonstrated that all VTEs were small and involved limited portion without lower leg edema or pleuroparenchymal complication. At the 6-month follow up MDCT, all types of VTEs were shown to be completely resolved, regardless of their location. All of the VTE lesions maintained an asymptomatic status for 6-month after surgery. VTE following UKA in Korean patients who do not receive thromboprophylaxis seems to occur frequently, but all of the VTEs are clinically insignificant and all VTEs are spontaneously regressed. Routine thromboprophylaxis or thrombolytic treatment in Korean patients undergoing UKA may not be necessary.