Risk of asymptomatic pulmonary embolism in patients with deep venous thrombosis

Epidemiology of deep vein thrombosis

Deep vein thrombosis (DVT) is a cause of considerable morbidity worldwide. It is a common clinical disease in the daily practice of several medical disciplines including general medicine, angiology, and internal medicine, as well as of interest to public health because of its preventability and its sensitivity to secular changes in the distribution of population risk factors. In this review we present a comprehensive overview of the epidemiological features of DVT, including incidence and risk factors. Additionally, we give an overview of the burden that DVT poses on modern health care systems.

Early diagnosis of occult pulmonary embolism secondary to lower limb fractures: summary of 18 cases

Objectives

Pulmonary thromboembolism is a severe but probably underdiagnosed disorder. Patients with lower limb fractures are at high risk for pulmonary thromboembolism. This study aimed to demonstrate the early identification strategies for occult pulmonary thromboembolism.

Methods

From January to December 2022, 18 patients diagnosed with pulmonary thromboembolism were reviewed for this study. Data on patients' demographics, laboratory test results, and radiographic findings were collected. Finally, the data was analyzed.

Results

Eighteen patients with lower limb fractures were included in this study. All of them present different symptoms, including 12 cases (12/18, 66%) of unexplained decrease in oxygen saturation; 16 patients had deep vein thrombosis in the lower limbs, with nine cases involving proximal veins and seven involving distal veins. One patient had an antithrombin III level of 35%. Thirteen cases were diagnosed with pulmonary embolism using CT pulmonary angiography. Four patients had pulmonary embolisms incidentally detected during coronary CT angiography, and one patient during aortic CT angiography.

Conclusion

Patients with lower limb fractures showing chest tightness and unexplained decrease in finger pulse oxygen levels should be assessed for pulmonary thromboembolism. Simultaneously, selecting appropriate diagnostic tools is essential to guaranteeing quick and accurate diagnosis.

Can Routine Investigation for Occult Pulmonary Embolism Be Justified in Patients with Deep Vein Thrombosis?

Purpose

This study aims to investigate whether routine screening for silent pulmonary embolism (PE) can be justified in patients with deep vein thrombosis (DVT).

Materials and Methods

We retrospectively analyzed the medical records of 201 patients with lower-extremity DVT admitted to the vascular surgery department of a single tertiary university center between 2019 and 2023. All patients underwent clinical evaluation, basic laboratory exams, a whole-leg colored duplex ultrasound, and a computed tomography pulmonary angiography (CTPA), to screen for an occult, underlying PE.

Results

The overall incidence of silent PE was 48.8%. The median admission D-dimer level was significantly higher in patients with silent PE than in those without PE (9.60 vs. 5.51 mg/L, P=0.001). A D-dimer value ≥5.14 mg/L was discriminant for predicting silent PE, with a sensitivity of 68.2% and a specificity of 59.3%. Silent PE was significantly more common on the right side, with the embolus located at the main pulmonary, lobar, segmental, and subsegmental arteries in 29.6%, 32.7%, 20.4%, and 17.3%, respectively. A higher incidence of occult PE was observed in patients with iliofemoral DVT (P=0.037), particularly when the thrombus extended to the inferior vena cava (P=0.003). Moreover, iliofemoral DVT was associated with a larger size and a more proximal location of the embolus (P=0.041). Multivariate logistic regression showed that male sex (odds ratio [OR]=2.46, 95% confidence interval [CI]: 1.39-3.53; P=0.026), cancer (OR=2.76, 95% CI: 1.45-4.07; P=0.017), previous venous thromboembolism (VTE) history (OR=2.67, 95% CI: 1.33-4.01; P=0.022), D-dimer value ≥5.14 mg/L (OR=2.24, 95% CI: 1.10-3.38; P=0.033), iliofemoral DVT (OR=2.13, 95% CI: 1.19-3.07; P=0.041), and thrombus extension to the IVC (OR=2.95, 95% CI: 1.43-4.47; P=0.009) served as independent predictors for silent PE.

Conclusion

A high incidence of silent PE was observed in patients with lower-extremity DVT. Screening of patients with DVT who have the aforementioned predictive risk factors using CTPA for silent PE may be needed and justified for the efficient management of VTE and its long-term complications.

Incidental central pulmonary emboli in outpatients with deep vein thrombosis

BACKGROUND

While it has been demonstrated that large asymptomatic pulmonary embolism (PE) can occur, many studies have assessed inpatients or patients with known risk factors for venous thromboembolism (such as malignancy). There are few data regarding incidental PE in outpatients with deep vein thrombosis (DVT) or assessing whether these emboli occur centrally or peripherally in the pulmonary arteries.

AIMS

To determine the rates of incidental central and peripheral PE in outpatients with proximal and distal DVT.

METHODS

This was a retrospective cross-sectional study of 120 patients attending our community imaging clinic between January 2015 and March 2020, with ultrasound-confirmed lower limb DVT, and subsequent computed tomography pulmonary angiogram (CTPA) within 24 h. Exclusion criteria were symptoms indicative of PE. Imaging reports were retrospectively reviewed to record the proximity of DVT and the location of any PE as either central (pulmonary trunk or main pulmonary arteries) or peripheral (lobar, segmental or subsegmental pulmonary arteries).

RESULTS

Incidental PE occurred in 71 patients (59.2%), with a rate of 77.5% in proximal and 50.0% in distal DVT. Sixteen patients had central PE (13.3% of all patients with DVT; 22.5% of all patients with PE). Two patients (both with proximal DVT) had PE in the pulmonary trunk.

CONCLUSIONS

Incidental PE occur frequently in outpatients with lower limb DVT, including the possibility of asymptomatic central emboli. Further studies with larger patient cohorts would be useful to assess the utility of baseline chest imaging in outpatients with DVT.

Integrating Cardiac Biomarkers and Electrocardiogram in Pulmonary Embolism Prognosis

Pulmonary embolism (PE) represents a significant clinical challenge that substantially impacts healthcare systems. This case report focuses on the nuances of risk stratification in PE, highlighted through the presentation of a 64-year-old female patient. The uniqueness of this case lies in the patient's atypical presentation, where decreased exercise tolerance was the sole symptom leading to the diagnosis of PE. The patient was found to have new-onset atrial fibrillation, elevated levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), and signs of right ventricular strain on imaging. This scenario underscores the necessity for a comprehensive assessment in PE cases, particularly when classic symptoms (e.g., tachycardia, shortness of breath, chest pain) are absent. We explore the incidence of PE in patients diagnosed with deep vein thrombosis, examining the critical role of cardiac biomarkers, including B-type natriuretic peptide, NT-proBNP, and troponins, in prognostication and their potential use in risk assessment tools for PE patients. Additionally, the significance of electrocardiogram evaluation in these patients and its role in risk stratification is thoroughly assessed.

Silent Pulmonary Embolism in Deep Vein Thrombosis: Relationship and Risk Factors

PURPOSE

This study aimed to evaluate risk factors for silent pulmonary embolism (PE) in symptomatic deep vein thrombosis (DVT) and investigate the relationship between DVT and silent PE.

METHODS

This was a single-centre, retrospective cohort study. Between 5 January 2015 and 31 December 2021, consecutive patients with symptomatic DVT received CT pulmonary angiography and CT venography were analyzed. Patient demographics, comorbidities, risk factors, and image findings were analyzed. The group differences were compared using a Chi-square test, Fisher's exact test, independent t test, or Mann-Whitney U test. Multivariant regression was used to determine predictive factors for silent PE.

RESULTS

A total of 355 patients (mean age, 60.5 ± 16.6 years) were included. The incidence of silent PE was 43.1%. The main or lobar pulmonary arteries were affected in 53.6% of patients, which is more often found in iliofemoral DVTs (56.6% vs 26.7%, p = .027). The multivariant analysis showed male patients (p = .042; OR 1.59; 95% CI, 1.02-2.50), inferior vena cava involvement (p = .043; OR 1.81; 95% CI, 1.02-3.20) and D-dimer value > 3.82 μg/ml (p < .001; OR 2.32; 95% CI, 1.43-3.77) were risk factors for silent PE. Unilateral DVT patients with ipsilateral iliac vein compression had a lower incidence of silent PE (28.8% vs 52.9%, p < .001).

CONCLUSION

Iliofemoral DVT was associated with a more proximal PE. The male patients, inferior vena cava involvement, and D-dimer > 3.82 μg/ml were risk factors for silent PE. Ipsilateral iliac vein compression reduced the incidence of silent PE.

Temporal trends in vena cava filter implantation in public health system inpatients: an 11-year analysis of the largest city in Brazil

Background

Vena cava filter implantation is considered a simple procedure, which can lead to overuse and over-indication. It is nevertheless associated with short and long-term complications.

Objectives

The goals of this study were to evaluate rates of vena cava filter implantation conducted by Brazil’s Unified Public Health System, analyzing in-hospital mortality and migration of patients from other cities seeking medical attention in São Paulo.

Methods

This study analyzed all vena cava filter procedures conducted from 2008 to 2018 in the city of São Paulo and registered on the public database using a big data system to conduct web scraping of publicly available databases.

Results

A total of 1324 vena cava filter implantations were analyzed. 60.5% of the patients were female; 61.7% were under 65 years old; 34.07% had registered addresses in other cities or states; and there was a 7.4% in-hospital mortality rate.

Conclusions

We observed an increase in the rates of use of vena cava filters up to 2010 and a decrease in rates from that year onwards, which coincides with the year that the Food and Drug Administration published a recommendation to better evaluate vena cava filter indications.

Pulmonary Embolism and Sigmoid Sinus Thrombosis After Translabyrinthine Vestibular Schwannoma Resection: A Retrospective Case Series

OBJECTIVE

To describe the presentation and treatment of patients developing pulmonary embolism following translabyrinthine approach for vestibular schwannoma resection.

METHODS

This was a retrospective case series of patients at 2 academic tertiary medical centers who developed symptomatic pulmonary embolism post-operatively following translabyrinthine approach for vestibular schwannoma resection and were found to have evidence of sigmoid sinus thrombosis.

RESULTS

Three patients were identified to have post-operative pulmonary emboli after translabyrinthine approach for vestibular schwannoma resection with sigmoid sinus or internal jugular vein clots in the absence of lower extremity deep vein thrombosis. Caprini scores for these patients were 5 or lower. All patients underwent CT pulmonary angiography and were confirmed to have pulmonary emboli. Two were promptly anticoagulated with heparin drips and transitioned to long-term oral anticoagulation therapy and 1 had delayed anticoagulation. None of these patients suffered from intracranial hemorrhage post-operatively.

CONCLUSIONS

Patients undergoing translabyrinthine approach for vestibular schwannoma can develop pulmonary embolism from sigmoid sinus entry or thrombosis. No clear guidelines exist for the management of this complication in the setting of recent craniotomy and the risk of intracranial hemorrhage must be considered prior to initiating anticoagulation.

Is routine screening for silent pulmonary embolism justified in patients with deep vein thrombosis?

The incidence of asymptomatic pulmonary embolism (PE) exceeds 70% in patients with deep venous thrombosis (DVT), even in cases of distal deep vein thrombosis. We report the case of a patient with a diagnosis of DVT in the lower left limb associated with asymptomatic PE who presented late symptoms due to this same PE. The absence of acute symptoms and the late onset of symptoms could have provoked doubts about the most appropriate treatment, resulting in unnecessary interventions, if pulmonary embolism had not already been diagnosed with tomography. In the present case, we demonstrate that computed tomography angiography conducted at the time of DVT diagnosis accurately diagnosed PE and prevented any misinterpretation of recurrent DVT in a patient already being medicated, which could have been mistakenly interpreted as demonstrating failure of anticoagulant therapy. Such a situation could lead to unnecessary intervention to fit an inferior vena cava filter. We cannot suggest that a classic medical conduct should be reformulated simply on the basis of a case report. However, we would be remiss not to suggest that well-designed studies should be carried out in the future to assess the need for this examination in the acute phase.

Imaging of acute and chronic thromboembolic disease: state of the art

Acute pulmonary embolism (PE) is a life-threatening condition that requires prompt diagnosis and treatment. Recent advances in imaging allow acute and rapid recognition even by the non-specialist radiologist. Most acute emboli resolve on anticoagulation without sequelae; however, some emboli fail to fully resolve becoming endothelialised with the development of chronic thromboembolic disease (CTED). Increased pulmonary vascular resistance arising from CTED may lead to chronic thromboembolic pulmonary hypertension (CTEPH) a debilitating disease affecting up to 5% of survivors of acute PE. Diagnostic evaluation is more complex in CTEPH/CTED than acute PE with subtle imaging features often being overlooked or misinterpreted. Differentiation of acute from chronic PE and from other forms of pulmonary hypertension has profound therapeutic implications. Diverse imaging techniques are available to diagnose and monitor PEs both in the acute and chronic setting. Broadly they include techniques that provide data on lung parenchymal perfusion (ventilation-perfusion [VQ] scintigraphy), angiographic techniques (computed tomography [CT], magnetic resonance imaging [MRI], and invasive angiography) or a combination of both (MR angiography and time-resolved angiography or dual-energy CT angiography). This review aims to describe state of the art imaging highlighting the strength and weaknesses of individual techniques in the diagnosis of acute and chronic PE.