Pulmonary embolism: Care standards in 2018

Correlation between Platelet-to-Lymphocyte Ratio, Neutrophil-to-Lymphocyte Ratio and Burden of Thrombus with Disease Severity in Patients with Pulmonary Thromboembolism

High neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are markers of subclinical inflammation and have been associated with prognosis and mortality in many diseases. In this study, we evaluated the comparative value of NLR and PLR in identifying high mortality risk in patients hospitalized with acute pulmonary thromboembolism (PTE), and their relationship with the anatomical burden of thrombus.Patients who were followed up due to PTE were evaluated retrospectively. NLR and PLR were calculated from complete blood counts. The thrombus burden was assessed by the Qanadli score; based on the patients' archival computed tomography angiography images. Mortality prediction was based on an algorithm using the Pulmonary Embolism Severity Index, echocardiographic findings, and troponin levels.Three hundred-two PTE patients were included in the study. Median NLR, PLR, and Qanadli score values were higher in nonsurvivors, with NLR (8.4 [2.2-18.9]) vs. (3.1 [0.4-13.1]), PLR (317 [87.6-525.3]) vs. (124.4 [30-476.3]), and Qanadli scores (21 [3-26]) vs. (9 [1-28]), respectively (p < 0.001). We showed that setting a threshold value of >4.45 for NLR and >151.59 for PLR significantly predicts the high mortality-risk group. In the receiver operating characteristic analysis, when the threshold value for the Qanadli score distinguishing between low-risk and high-risk disease was set at 15.5, the sensitivity was calculated as 98.8% and the specificity was 94.9% (p = 0.001).This study showed that NLR, PLR, and Qanadli scores can provide essential contributions to the clinician's determination of the anatomical burden of thrombus and disease severity in PTE patients.

Venous thromboembolism: Why is it still a significant health problem?

BACKGROUND

Venous thromboembolism (VTE) remains the third leading cause of acute cardiovascular syndrome following myocardial infarction and ischemic stroke. The global burden of disease worldwide is high and shows a steady upward trend in recent years with an incidence of 1-2 per 1000 adults per year. The overarching goal of the initial management of VTE is to prevent early and late adverse outcomes. Rapid evaluation and therapeutic intervention is vital to improving prognosis.

METHODS

We searched PubMed, Science Direct and Scopus databases for articles published in the last 10 years. Additionally, some earlier articles were analyzed.

RESULTS

For the purposes of this review, we discussed how understanding the epidemiology of VTE and the current knowledge of early and late complications of this disease have shaped the current approach to VTE prevention. We also analyzed the current knowledge and the most up-to-date information about VTE in COVID-19 infection. Contemporary perspective presented in this article on mortality in VTE, the incidence of recurrences, the risk of major bleeding during therapy and the chronic complications indicate why this is a major challenge for today's medicine and a current target for further research.

CONCLUSIONS

Understanding the interaction between environmental and genetic factors appears to be crucial in the diagnostic process. It can provide insight into the pathophysiology of VTE, potentially identifying options for targeted prevention and treatment. However, due to differences in clinical presentation, diagnosing pulmonary embolism may not be an easy task which perfectly illustrates the scale and complexity of the disease.

Diagnostic test accuracy of imaging modalities for adults with acute pulmonary embolism: A systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aimed to evaluate the current literature on diagnostic test accuracy (DTA) of imaging modalities for adults with acute pulmonary embolism (APE).

BACKGROUND

Medical imaging plays an integral role in evaluating and managing those with APE. Guidance for imaging modality use for APE diagnosis varies due to a lack of clinical standardisation. Despite this, CTPA remains the first-line imaging modality used by clinicians.

METHODS

A literature search of PubMed, EMBASE, Trove and Mednar databases (2012-2020; English language) was performed. Studies assessing the DTA of imaging modalities for APE diagnosis were included. DTA studies methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2 tool). Results of eligible studies were pooled using random or fixed effects modelling the calculate the pooled DTA of explored imaging modalities for APE. The Higgins I² test were performed to assess between study heterogeneity.

RESULTS

10 Studies, involving 998 participants, were enrolled and pooled using the random effects model. Of the explored modalities, magnetic resonance imaging (MRI), specifically pulmonary MRI and magnetic resonance pulmonary angiography (MRPA) exhibited the highest pooled DTA. Sensitivity, specificity, negative likelihood ratio, positive likelihood ratio and diagnostic odds ratio for MRPA were 0.952 (95% CI, 0.881 to 0.987), 0.857 (95% CI, 0.637 to 0.97), 5.631 (95% CI, 2.163 to 14.659), 0.06 (95% CI, 0.007 to 0.537) and 80.310 (95% CI, 15.607 to 413.25) respectively. Based on the QUADAS-2 criteria, most studies presented low to moderate risk of bias and concern regarding applicability.

CONCLUSION

The explored ultrasound and MRI protocols which exhibit a lower radiation burden when compared to the current gold standard computed tomography pulmonary angiography (CTPA), have acceptable diagnostic accuracy for APE and can be useful in certain situations.

Discovery of plasma biomarkers with data-independent acquisition mass spectrometry and antibody microarray for diagnosis and risk stratification of pulmonary embolism

BACKGROUND

Pulmonary embolism (PE) is a leading cause of cardiovascular mortality worldwide. Rapid and accurate diagnosis and risk stratification are crucial for timely treatment options, especially in high-risk PE.

OBJECTIVES

The study aims to profile the comprehensive changes of plasma proteomes in PE patients and identify the potential biomarkers for both diagnosis and risk stratification.

PATIENTS/METHODS

Based on the data-independent acquisition mass spectrometry and antibody array proteomic technology, we screened the plasma samples (13 and 32 proteomes, respectively) in two independent studies consisting of high-risk PE patients, non-high-risk PE patients, and healthy controls. Some significantly differentially expressed proteins were quantified by ELISA in a new study group with 50 PE patients and 26 healthy controls.

RESULTS

We identified 207 and 70 differentially expressed proteins in PE and high-risk PE. These proteins were involved in multiple thrombosis-associated biological processes including blood coagulation, inflammation, injury, repair, and chemokine-mediated cellular response. It was verified that five proteins including SAA1, S100A8, TNC, GSN, and HRG had significant change in PE and/or in high-risk PE. The receiver operating characteristic curve analysis based on binary logistic regression showed that the area under the curve (AUC) of SAA1, S100A8, and TNC in PE diagnosis were 0.882, 0.788, and 0.795, and AUC of S100A8 and TNC in high-risk PE diagnosis were 0.773 and 0.720.

CONCLUSION

As predictors of inflammation or injury repair, SAA1, S100A8, and TNC are potential plasma biomarkers for the diagnosis and risk stratification of PE.

Improving compliance of risk assessment and nonpharmacological interventions for deep venous thrombosis prevention in a respiratory ICU: a best practice implementation project

OBJECTIVES

To increase the compliance with deep venous thrombosis (DVT) nonpharmacologic prophylaxis best practice recommendations while ensuring appropriate and structured nonpharmacologic prophylaxis for patients in the respiratory ICU.

BACKGROUND

DVT is a major problem for patients, with those who are critically ill representing a high-risk population for developing the condition. Nonpharmacologic prophylaxis is considered an effective intervention. However, the application of such interventions in practice has not been optimal to date.

METHODS

The current project was conducted in a respiratory ICU of a tertiary hospital. Audit criteria were developed on the basis of an evidence summary developed by the Joanna Briggs Institute, whereby the institute's Practical Application of Clinical Evidence System program to facilitate an audit and feedback cycle was utilized as an implementation framework. Baseline and follow-up audits on nonpharmacological DVT prophylaxis were conducted for 35 patients against five evidence-based recommendations. In addition, the nurses' knowledge and attitude regarding DVT prophylaxis were investigated both prior to and postimplementation.

RESULTS

In the baseline audit, compliance with the five evidence-based audit criteria was less than 15%. After the implementation of strategies including education, person-centered care, financial and human-resource support, there was a significant improvement in all the audit criteria. In addition, improvements in the nurses' knowledge and attitude regarding DVT prophylaxis were reported. The rate of discharged patients due to a deterioration of their condition decreased from 31.4 to 5.7% in the follow-up cycle. One DVT patient occurred in the baseline data, whereas no new incidences of DVT were found in the follow-up data.

CONCLUSION

The project not only improved nurses' knowledge and attitude regarding DVT prevention, but also remarkably improved the implementation of nonpharmacological DVT prophylaxis. The application of evidence-based nonpharmacological DVT prophylaxis may improve patients' outcomes in the ICU.

A patient with shortness of breath after total hip replacement

Clinical presentation of pulmonary embolism (PE) frequently is nonspecific, making patient evaluation and diagnosis challenging. Clinicians must be alert for signs and symptoms of PE in patients with risk factors and have a low threshold for ordering appropriate imaging and laboratory tests. Initial treatment concentrates on patient oxygenation and stabilization; further management of PE depends on the patient's hemodynamic stability and right ventricular strain. This article focuses on a minimally symptomatic patient with a history of hip fracture and total hip replacement who was found to have a saddle PE.

Association between risk stratification for pulmonary embolism and deep vein thrombosis of lower extremities

BACKGROUND

The association of clinical risk factors, in particular deep vein thrombosis (DVT), with risk stratification for pulmonary embolism (PE) remains to be identified. We therefore aimed to establish the relationship between risk stratification of PE patients and DVT of lower extremities.

METHODS

In this retrospective study, 93 out of 485 PE patients with uncompleted clinical data were excluded, resulting in 392 patients included for analysis. Based on the ESC criteria, 24, 171, and 197 patients were categorized into high (6.1%), intermediate (43.6%), and low risk (50.3%) subgroups, respectively.

RESULTS

DVT was detected in 304 patients (77.6%). The incidence of DVT in patients with high and intermediate risk PE was much lower than in those patients with low risk PE (67.2% vs 87.8%, P < .0001). Further analyses of the 304 patients with DVT showed higher incidence of high and intermediate risk PE in patients with isolated distal DVT than proximal DVT (59.0% vs 39.1%, P = .005), with asymptomatic DVT than symptomatic DVT (63.0% vs 36.8%, P < .0001), and with bilateral DVT than unilateral DVT (54.5% vs 39.9%, P = .03). Stepwise logistic regression showed that symptomatic or asymptomatic DVT was an independent risk factor for risk stratification of PE patients with DVT (0.320, 95% confidence interval, 0.186-0.550).

CONCLUSIONS

Patients with high and intermediate risk PE presented lower incidence of DVT compared with patients with low risk PE. In PE patients with comorbid DVT, asymptomatic DVT is an independent risk factor for high and intermediate risk of PE.

An in vitro Model System for Evaluating Remote Magnetic Nanoparticle Movement and Fibrinolysis

Background

Thrombotic events continue to be a major cause of morbidity and mortality worldwide. Tissue plasminogen activator (tPA) is used for the treatment of acute ischemic stroke and other thrombotic disorders. Use of tPA is limited by its narrow therapeutic time window, hemorrhagic complications, and insufficient delivery to the location of the thrombus. Magnetic nanoparticles (MNPs) have been proposed for targeting tPA delivery. It would be advantageous to develop an improved in vitro model of clot formation, to screen thrombolytic therapies that could be enhanced by addition of MNPs, and to test magnetic drug targeting at human-sized distances.

Methods

We utilized commercially available blood and endothelial cells to construct 1/8th inch (and larger) biomimetic vascular channels in acrylic trays. MNP clusters were moved at a distance by a rotating permanent magnet and moved along the channels by surface walking. The effect of different transport media on MNP velocity was studied using video photography. MNPs with and without tPA were analyzed to determine their velocities in the channels, and their fibrinolytic effect in wells and the trays. 

Results

MNP clusters could be moved through fluids including blood, at human-sized distances, down straight or branched channels, using the rotating permanent magnet. The greatest MNP velocity was closest to the magnet: 0.76 ± 0.03 cm/sec. In serum, the average MNP velocity was 0.10 ± 0.02 cm/sec. MNPs were found to enhance tPA delivery, and cause fibrinolysis in both static and dynamic studies. Fibrinolysis was observed to occur in 85% of the dynamic MNP + tPA experiments.

Conclusion

MNPs hold great promise for use in augmenting delivery of tPA for the treatment of stroke and other thrombotic conditions. This model system facilitates side by side comparisons of MNP-facilitated drug delivery, at a human scale.

EANM guideline for ventilation/perfusion single-photon emission computed tomography (SPECT) for diagnosis of pulmonary embolism and beyond

These guidelines update the previous EANM 2009 guidelines on the diagnosis of pulmonary embolism (PE). Relevant new aspects are related to (a) quantification of PE and other ventilation/perfusion defects; (b) follow-up of patients with PE; (c) chronic PE; and (d) description of additional pulmonary physiological changes leading to diagnoses of left ventricular heart failure (HF), chronic obstructive pulmonary disease (COPD) and pneumonia. The diagnosis of PE should be reported when a mismatch of one segment or two subsegments is found. For ventilation, Technegas or krypton gas is preferred over diethylene triamine pentaacetic acid (DTPA) in patients with COPD. Tomographic imaging with V/PSPECT has higher sensitivity and specificity for PE compared with planar imaging. Absence of contraindications makes V/PSPECT an essential method for the diagnosis of PE. When V/PSPECT is combined with a low-dose CT, the specificity of the test can be further improved, especially in patients with other lung diseases. Pitfalls in V/PSPECT interpretation are discussed. In conclusion, V/PSPECT is strongly recommended as it accurately establishes the diagnosis of PE even in the presence of diseases like COPD, HF and pneumonia and has no contraindications.

Update on Thrombolytic Therapy in Acute Pulmonary Thromboembolism

Thrombolytic treatment accelerates the dissolution of thrombus in acute pulmonary thromboembolism (PTE) and is potentially a lifesaving treatment. High-risk PTE is the clearest indication for this therapy, and its use in intermediate-risk cases is still controversial. A PTE response team may enable a rapid and effective determination of risk and treatment in these controversial clinical cases. Approved thrombolytic agents for the PTE treatment are streptokinase, urokinase, and alteplase. Currently, the most widely used agent is alteplase. It has a short infusion time (2 h) and a rapid effect. Newer, unapproved agents for the PTE treatment are tenecteplase and reteplase. The active resolution of thrombus via thrombolytic agents improves rapidly pulmonary perfusion, hemodynamic defect, gas exchange, and right ventricular dysfunction. However, it is important to determine appropriate candidates carefully, to prevent hemorrhage, which is the most important side effect of these drugs. Catheter-directed thrombolysis seems to be an alternative in patients not eligible for systemic thrombolytic therapy.