Advances in the diagnosis and management of acute pulmonary embolism

The Prognostic Value of Total Blood Count Parameter Ratios in Acute Pulmonary Embolism

Background/Objectives: Acute pulmonary embolism (PE) is a leading cause of cardiovascular mortality, characterized by nonspecific symptoms and variable clinical presentations. Accurate risk stratification is essential for effective management. While conventional tools like the simplified pulmonary embolism severity index (sPESI) and imaging modalities are widely used, they are often costly and have limitations in predictive accuracy. Inflammatory and coagulative markers, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean-platelet-volume-to-lymphocyte ratio (MPVLR), have shown promise in thrombotic conditions. This study explores their prognostic value in PE, focusing on their associations with risk stratification and clinical outcomes. Methods: This retrospective study included 231 adult patients diagnosed with PE at a tertiary care center. Exclusion criteria included recent infection, autoimmune diseases, or immunosuppressive therapy. Laboratory data, clinical parameters, and outcomes (e.g., hospitalization duration, complications, and mortality) were analyzed. Ratios were calculated from routine blood counts, and statistical comparisons were conducted between low- and high-risk groups based on sPESI. Results: High-risk patients (n = 203) exhibited significantly higher troponin, blood urea nitrogen, aspartate aminotransferase, lactate, the NLR (median 4.9 vs. 2.7, p = 0.005), and the MPVLR (median 7.1 vs. 3.9, p = 0.001) compared to low-risk patients. The PLR showed no significant difference between risk groups (p = 0.233). An elevated NLR, PLR, and MPVLR correlated with ICU admission, intubation, and mortality (p < 0.001, p < 0.007, and p < 0.001, respectively). The NLR was the most consistently associated with hospitalization duration and mortality, while the MPVLR and PLR were less predictive of overall hospitalization. Conclusions: The NLR, MPVLR, and PLR are cost-effective, easily calculable markers with the potential for improving risk stratification in PE patients. Among these, the NLR showed the strongest prognostic value, correlating with multiple clinical outcomes. Multicenter studies are needed to validate these findings further and establish clinical utility.

Innovation in Catheter-Directed Therapy for Intermediate-High-Risk and High-Risk Pulmonary Embolism

Although anticoagulation remains the cornerstone treatment for patients with acute pulmonary embolism (PE), catheter-directed therapy (CDT) has generated great interest as an adjunctive option for those presenting with hemodynamic decompensation or high risk for deterioration and in whom systemic thrombolysis has failed or is contraindicated. However, randomized controlled data supporting the efficacy and safety of CDT in addition to antithrombotic therapy in patients with high-risk and intermediate- to high-risk PE compared with anticoagulation and systemic thrombolysis alone are lacking. This paucity of high-quality data hampers guideline recommendations regarding the optimal therapeutic approach in such patients with PE. The aim of the present paper is to critically appraise the current evidence for CDT in patients with high-risk and intermediate- to high-risk PE and to highlight major areas of innovation in the recent literature. In addition, the authors describe unmet clinical and research needs, potential strategies to resolve these knowledge gaps, and pathways for device selection.

A Systematic Review of Double Low-dose CT Pulmonary Angiography in Pulmonary Embolism

BACKGROUND

The aim of this study is to perform a systematic review of the feasibility and clinical application of double low-dose CT pulmonary angiography (CTPA) in the diagnosis of patients with suspected pulmonary embolism.

DISCUSSION

A total of 13 studies were found to meet selection criteria reporting both low radiation dose (70 or 80 kVp versus 100 or 120 kVp) and low contrast medium dose CTPA protocols. Lowdose CTPA resulted in radiation dose reduction from 29.6% to 87.5% in 12 studies (range: 0.4 to 23.5 mSv), while in one study, radiation dose was increased in the dual-energy CT group when compared to the standard 120 kVp group. CTPA with use of low contrast medium volume (range: 20 to 75 ml) was compared to standard CTPA (range: 50 to 101 ml) in 12 studies with reduction between 25 and 67%, while in the remaining study, low iodine concentration was used with 23% dose reduction achieved. Quantitative assessment of image quality (in terms of signal-to-noise ratio and contrast-to-noise ratio) showed that low-dose CTPA was associated with higher, lower and no change in image quality in 3, 3 and 6 studies, respectively when compared to the standard CTPA protocol. The subjective assessment indicated similar image quality in 11 studies between low-dose and standard CTPA groups, and improved image quality in 1 study with low-dose CTPA.

CONCLUSION

This review shows that double low-dose CTPA is feasible in the diagnosis of pulmonary embolism with significant reductions in both radiation and contrast medium doses, without compromising diagnostic image quality.

The Predictive Value of microRNA-134 and microRNA-1233 for the Early Diagnosis of Acute Exacerbation of Chronic Obstructive Pulmonary Disease with Acute Pulmonary Embolism

Background

The differential diagnosis of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with acute pulmonary embolism (APE) complications are difficult because of the variability of clinical presentations and the shortage of an unfailing screening biomarkers or instruments.

Objective

Aimed to detect and compare the expression of serum microRNAs (miR-1233, miR-134) in AECOPD patients complicated with APE.

Patients/Methods

Blood samples were collected from 52 AECOPD patients (13 patients with APE complications, 39 patients without APE) and 10 patients with stable COPD. Serum miRNAs expression was detected with real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The levels of plasma D-dimers were determined by detection with an enzyme-linked immunosorbent assay (ELISA). The receiver-operator characteristic (ROC) curve was used for evaluating the diagnostic accuracy of the studied miRNAs.

Results

According to the Wells score, 42 of the 52 AECOPD patients were unlikely to have APE (≤4 points), whereas the remaining 10 (>4 points) were likely to have APE. There were 4 cases (4/13 30.8%) in the AECOPD combined with APE group with a Wells score of >4 points. The expression levels of miR-1233 and miR-134 in the serum were considerably upregulated in the AECOPD+APE group compared with the AECOPD group and the stable COPD group (P<0.05). The areas under the curve (AUCs) for miR-134 and miR-1233 were, respectively, 0.931 (95% CI 0.863-0.999) (P<0.05) and 0.884 (95% CI 0.79-0.978) (P<0.05) and were higher compared with the AUC for D-dimer of 0.628 (95% CI 0.447-0.809), the AUC for age-adjusted D-dimer of 0.705 (95% CI 0.525-0.885) and the AUC for Wells score of 0.577 (95% CI 0.389-0.765).

Conclusion

Our study indicated that serum miR-1233 and miR-134 have high clinical value in the early diagnosis of AECOPD patients combined with APE, or could be used as potential biomarkers for clinical identification of AECOPD with or without APE complication.

Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios Predict All-Cause Mortality in Acute Pulmonary Embolism

The aim of this study was to investigate the utility of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) to predict all-cause mortality in patients presenting with acute pulmonary embolism (PE). Three hundred consecutive patients with acute PE between March 2016 and December 2018 were retrospectively analyzed. We identified 191 patients who met the study inclusion criteria. Twenty-eight patients died during the study period. There was a significant difference in PLR, but not NLR, between patients with low risk, submassive, and massive risk PE (P = .02 and P = .58, respectively, by the Kruskal-Wallis test). Elevated NLR and PLR were associated with all-cause mortality (P < .01 and P < .01, respectively). Neutrophil-to-lymphocyte ratio of 5.46 was associated with all-cause mortality with sensitivity of 75.0% and specificity of 66.9% (area under the curve [AUC]: 0.692 [95% confidence interval, CI]: 0.568-0.816); P < .01). Platelet-to-lymphocyte ratio of 256.6 was associated with all-cause mortality with sensitivity of 53.6% and specificity of 82.2% (AUC: 0.693 [95% CI: 0.580-0.805]; P < .01). Neutrophil-to-lymphocyte ratio and PLR are simple biomarkers that are readily available from routine laboratory values and may be useful components of PE risk prediction models.

Anticoagulant treatment for subsegmental pulmonary embolism

BACKGROUND

Acute pulmonary embolism (PE) is a common cause of death, accounting for 50,000 to 200,000 deaths annually. It is the third most common cause of mortality among the cardiovascular diseases, after coronary artery disease and stroke. The advent of multi-detector computed tomographic pulmonary angiography (CTPA) has allowed better assessment of PE regarding visualisation of the peripheral pulmonary arteries, increasing its rate of diagnosis. More cases of peripheral PEs, such as isolated subsegmental PE (SSPE) and incidental PE, have thereby been identified. These two conditions are usually found in patients with few or none of the classic PE symptoms such as haemoptysis or pleuritic pain, acute dyspnoea or circulatory collapse. However, in patients with reduced cardiopulmonary reserve, classic PE symptoms can be found with isolated SSPEs. Incidental SSPE is found casually in asymptomatic patients, usually by diagnostic imaging performed for other reasons (for example routine CT for cancer staging in oncology patients). Traditionally, all PEs are anticoagulated in a similar manner independent of their location, or number and size of the thrombi. It has been suggested that many patients with SSPE may be treated without benefit, increasing adverse events by a possible unnecessary use of anticoagulants. Patients with isolated SSPE, or incidental PE, may have a more benign clinical presentation compared to those with proximal PEs. However, the clinical significance in patients, and their prognosis, needs to be studied to evaluate whether anticoagulation therapy is required. This is the second update of the Cochrane systematic review published in 2014.

OBJECTIVES

To assess the effectiveness and safety of anticoagulation therapy versus control in patients with isolated subsegmental pulmonary embolism (SSPE) or incidental SSPE.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 26 November 2019. We also undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials of anticoagulation therapy versus control in patients with SSPE or incidental SSPE.

DATA COLLECTION AND ANALYSIS

Two review authors inspected all citations identified to ensure reliable assessment. If relevant studies were identified, we planned for two review authors to independently extract data and to assess the methodological quality of identified trials using the criteria recommended in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We did not identify any studies that met the inclusion criteria.

AUTHORS' CONCLUSIONS

There is no evidence from randomised controlled trials to assess the effectiveness and safety of anticoagulation therapy versus control in patients with isolated subsegmental pulmonary embolism (SSPE) or incidental SSPE. Well-conducted research is required before informed practice decisions can be made.

Computed tomography pulmonary angiography using high-pitch dual-source scanner technology

Objectives:

To compare use of ultra-fast high-pitch dual-source free-breathing computed tomography pulmonary angiogram (CTPA) with conventional standard-pitch single-source breath-hold CTPA.

Methods:

This retrospective comparative study was conducted in Radiology Department at King Fahad Military Medical Complex Dhahran, Saudi Arabia from July 2016 to December 2017. Patients (N=130) were divided into 2 groups, each having 65 consecutive patients; Group-1 (single-source CT) and Group-2 (dual-source CT). Previously treated pulmonary embolism cases, pregnant patients and those with incomplete data were excluded. Image quality was subjectively assessed by 2 readers for adequacy of contrast opacification and pulmonary vessel outline, and presence of artifacts (breathing motion, cardiac pulsation, and contrast related). Scan acquisition times and radiation doses were also compared. Chi-square and t-test were used to determine association.

Results:

Improved image quality (optimal studies without artifacts 91%) was seen in Group-2 compared to Group-1 (optimal studies without artifacts 75.4%). Also, reduced scan time (1-2 sec.) and radiation dose (mean dose length product (DLP)-248 mGy-cm) were observed in Group-2 compared to Group-1 (scan time- 6.5 sec, mean DLP-375). Results were found significant (p<0.05).

Conclusion:

High-pitch dual-source CT with free-breathing yields better image quality, reduces image acquisition time and radiation doses.

Use of a three-tiered clinical decision rule to quantify unnecessary radiological investigation of suspected pulmonary embolism

BACKGROUND

Clinical decision rules for suspected pulmonary embolism are proposed to identify patients suitable for discharge without radiological investigation. Their use varies between institutions.

AIMS

To quantify unnecessary radiological investigations for suspected pulmonary embolism (PE) as defined by a newly proposed three-tiered clinical decision rule incorporating the revised Geneva score, Pulmonary Embolism Rule-Out Criteria and D-dimer. To quantify missed diagnosis of PE if the proposed clinical decision rule were followed.

METHODS

A retrospective audit was conducted; applying the proposed clinical decision rule to 584 emergency department (ED)-based encounters at the Royal Adelaide Hospital from May to November 2015. Encounters were confined to emergency presentations where suspected acute PE was investigated with computed tomography pulmonary angiography or ventilation-perfusion scanning; inpatient and follow-up studies were excluded. Sensitivity, specificity, positive predictive value and negative predictive value of the proposed clinical decision rule within the studied population were calculated.

RESULTS

Data were obtained for 584 patient encounters where suspected PE was investigated radiologically. Applied retrospectively, the proposed clinical decision rule had a negative predictive value of 97.7% and a sensitivity of 98.5% for radiologically proven PE; 9.2% of scans could have been avoided. One case of PE would have been missed; a false-negative rate of 1.5%.

CONCLUSION

Retrospective application of the proposed clinical decision rule to the studied cohort indicates at least 9% of radiological investigations were unnecessary. A prospective study is needed to assess the safety and cost-effectiveness of applying such a pathway to all patients presenting to ED with suspected PE.

State-of-the-Art Pulmonary CT Angiography for Acute Pulmonary Embolism

OBJECTIVE

Pulmonary CT angiography (CTA) is the imaging modality of choice in suspected acute pulmonary embolism (PE). Current pulmonary CTA techniques involve ever lower doses of contrast medium and radiation along with advanced postprocessing applications to enhance image quality, diagnostic accuracy, and provide added value in patient management. The objective of this article is to summarize these current developments and discuss the appropriate use of state-of-the-art pulmonary CTA.

CONCLUSION

Pulmonary CTA is well established as a fast and reliable means of excluding or diagnosing PE. Continued developments in CT system hardware and postprocessing techniques will allow incremental reductions in radiation and contrast material requirements while improving image quality. Advances in risk stratification and prognostication from pulmonary CTA examinations should further refine its clinical value while minimizing the potential harm from overutilization and overdiagnosis.

MiR-28-3p as a potential plasma marker in diagnosis of pulmonary embolism

OBJECTIVES

Circulating miRNAs have been reported to have potential in detecting various diseases. However, few studies explored differentially expressed miRNAs in plasma of patients with pulmonary embolism (PE). Our study is to identify plasma miRNAs which can serve as potential biomarkers of PE.

MATERIALS AND METHODS

Exiqon miRCURY Ready-to-Use PCR Human panel I+II V1.M was conducted to identify differently expressed miRNAs in pooled plasma samples of PE patients compared with normal controls. Expressions of identified miRNAs were assessed in 37 PE patients as well as matched normal individuals followed by validation on six Beagle dogs by quantitative reverse transcription polymerase chain reaction (qRT-PCR).

RESULTS

Twelve miRNAs were identified from the screening phase. Moreover, miR-134, previously reported related with PE, and hypoxia-induced miR-210 were also submitted to the validation phase. Only miR-28-3p was found significantly elevated in the plasma of PE patients. Compared with the level of plasma miR-28-3p of the dogs before PE, the elevated miR-28-3p did not alter significantly at 1, 2, 4 and 6h after PE. The area under the receiver operating characteristic (ROC) curve of plasma miR-28-3p was 0.792 (95% confidence interval: 0.689-0.896). KEGG pathway analysis showed that miR-28-3p might involve in PE related pathways such as inositol phosphate metabolism and phosphatidylinositol signaling system.

CONCLUSION

Our study indicated that elevated plasma miR-28-3p could be used as a non-invasive and stable biomarker in the detection of PE. Further researches on the miRNA are warranted.

Subsegmental pulmonary embolism: A narrative review

Through the introduction of computed tomography pulmonary angiography (CTPA) for diagnosis of the pulmonary embolism (PE), the high sensitivity of this diagnostic tool led to detecting peripheral filling defects as small as 2-3mm, termed as subsegmental pulmonary embolism (SSPE). However, despite these substantial increases in diagnosis of small pulmonary embolism, there are minimal changes in mortality. Moreover, SSPE patients generally are hemodynamically stable with mild clinical presentation, lower serum level of biomarkers, lower incidence of associated proximal DVTs and less frequent echocardiographic changes compared to the patients with emboli located in more central pulmonary arteries. However, the pros and cons of anticoagulant therapy versus non-treating, monitoring protocol and exact long term outcome of these patients are still unclear. In this article we review existing evidence and provide an overview of what is known about the diagnosis and management of subsegmental pulmonary embolism.

CT angiography in the diagnosis of cardiovascular disease: a transformation in cardiovascular CT practice

Computed tomography (CT) angiography represents the most important technical development in CT imaging and it has challenged invasive angiography in the diagnostic evaluation of cardiovascular abnormalities. Over the last decades, technological evolution in CT imaging has enabled CT angiography to become a first-line imaging modality in the diagnosis of cardiovascular disease. This review provides an overview of the diagnostic applications of CT angiography (CTA) in cardiovascular disease, with a focus on selected clinical challenges in some common cardiovascular abnormalities, which include abdominal aortic aneurysm (AAA), aortic dissection, pulmonary embolism (PE) and coronary artery disease. An evidence-based review is conducted to demonstrate how CT angiography has changed our approach in the diagnosis and management of cardiovascular disease. Radiation dose reduction strategies are also discussed to show how CT angiography can be performed in a low-dose protocol in the current clinical practice.