Decision-Making with D-Dimer in the Diagnosis of Pulmonary Embolism

Multi-factor early monitoring method based on D-dimer for iliac crest flap loss

BACKGROUND

In recent years, the utilization of autogenous vascularized iliac crest flap for repairing jaw defects has seen a significant rise. However, the visual monitoring of iliac bone flaps present challenges, frequently leading to delayed detection of flap loss. Consequently, there's a urgent need to develop effective indicators for monitoring postoperative complications in iliac crest flaps.

METHODS

A retrospective analysis was conducted on 160 patients who underwent vascularized iliac crest flap transplantation for jawbone reconstruction from January 2020 to December 2022. We investigated the changes in D-dimer levels among patients with or without postoperative complications. Additionally, multivariable logistic regression analysis was performed to explore potential individual risk factors, including surgical duration, age, pathology type, absolute and relative D-dimer levels, and gender, culminating in the development of a nomogram.

RESULTS

On the first day following surgery, patients who experienced thrombosis exhibited a substantial increase in plasma D-dimer levels, reaching 3.75 mg/L, 13.84 times higher than the baseline. This difference was statistically significant (P < 0.05) compared to patients without postoperative complications. Furthermore, the nomogram we have developed and validated effectively predicts venous thrombosis, assigning individual risk scores to patients. This predictive tool was assessed in both training and validation cohorts, achieving areas under the curve (AUC) of 0.630 and 0.600, with the 95% confidence intervals of 0.452-0.807 and 0.243-0.957, respectively.

CONCLUSIONS

Our study illustrates that postoperative plasma D-dimer levels can serve as a sensitive biomarker for monitoring thrombosis-induced flap loss. Moreover, we have developed a novel prediction model that integrates multiple factors, thereby enhancing the accuracy of early identification of patients at risk of thrombosis-associated flap loss. This advancement contributes to improving the overall management and outcomes of such procedures.

ITIH4 is a predictor for coronary thrombus in coronary arteriography patients

Aim: To explore potential value of inter-alpha-trypsin inhibitor heavy chain-4 (ITIH4) for coronary artery disease (CAD) diagnosis. Patients & methods: We recruited the patients who received coronary arteriography (CAG) examination. The enzyme-linked immunosorbent assay was used to detect plasma ITIH4. Results: ITIH4 level was lower expression in CAD patients than that in patients of control group, and was negatively correlated with C-reactive protein (CRP). ITIH4 level is no differences between ST-elevated myocardial infarction (STEMI) and non-ST-elevated myocardial infarction (NSTEMI) patients. However, its expression was significantly correlated with D-Dimer and thrombin time, and the logistic analysis confirmed predictive value of ITIH4 for visible thrombus in coronary. Conclusion: ITIH4 may be a useful biomarker in CAD diagnosis, and to predict visible thrombus in coronary.

Emergency admission plasma D-dimer: a novel predictor for symptomatic intracranial hemorrhage after thrombectomy in acute ischemic stroke

BACKGROUND

Symptomatic intracranial hemorrhage (sICH) is a common and severe complication in patients with acute ischemic stroke (AIS) after treatment with thrombectomy.

OBJECTIVE

To explore the ability of admission plasma D-dimer levels to predict sICH after thrombectomy.

METHODS

Between February 2018 and August 2021, consecutive patients with AIS who underwent thrombectomy at our single comprehensive stroke center were retrospectively enrolled. sICH was defined according to the criterion of the Heidelberg Bleeding Classification. Logistic regression analysis was performed to determine the risk factors of sICH. The overall discriminative ability of D-dimer levels in predicting sICH was evaluated by adopting a receiver operating characteristic (ROC) curve.

RESULTS

Of the 395 enrolled patients, 48 (12.2%) had sICH. Patients with sICH were older (72.9 vs 69.3 years, P=0.037), more often female (62.5% vs 45.5%, P=0.027), had higher D-dimer levels (2.70 vs 0.74 mg/L, P<0.001), higher National Institutes of Health Stroke Scale score (20 vs 15, P<0.001), lower Alberta Stroke Program Early CT Score (8 vs 9, P<0.001), a higher proportion of internal carotid artery occlusions (56.2% vs 30.3%, P<0.001), and less commonly had large-artery atherosclerosis stroke etiology (12.5% vs 32.3%, P=0.010) than patients without sICH. After adjustment for potential confounders, D-dimer levels (adjusted OR=2.45, 95% CI 1.75 to 3.43, P<0.001) remained significantly associated with sICH. Based on the ROC, the D-dimer as a predictor for predicting sICH, presented with a specificity of 86.2%, a negative predictive value of 94.6%, and an area under the curve of 0.774.

CONCLUSION

Elevated admission D-dimer levels are an independent predictor of sICH in patients with AIS after thrombectomy.

Clinical Features Associated with 'Normal Range' Fibrin D-Dimer Levels in Atrial Fibrillation Patients with Left Atrial Thrombus

BACKGROUND

Left atrial thrombus (LAT) often complicates with atrial fibrillation (AF). The evidence whether fibrin D-dimer levels could be used as a predictive biomarker for LAT is contradictory. This study firstly investigated the relationship between 'normal range' D-dimer and prevalent LAT. Second, we explored factors contributing to normal D-dimer levels in the presence of LAT.

METHODS

We studied 244 AF patients with LAT (mean age: 59.9 years, SD:11.7; 53.3% female): of these, 103 (42.2%) had normal D-dimer, 25 (10.2%) had atrial thrombus exclusion score (ATE score) of 0 19 (16.7%) males had CHA₂DS₂-VASc score of 0, 21(16.2%) females had CHA₂DS₂-VASc score of 1 and 16 had overlapped ATE score of 0 and CHA₂DS₂-VASc score of 0 (N = 8 if male) or CHA₂DS₂-VASc score of 1(N = 8 if female). Using multivariate binary analysis, larger left atrial diameter (LAD; adjusted OR: 1.06, 1.03-1.10, p = 0.001) were associated with increased D-dimer. Patients with high body mass index (BMI), hypertension history and previous anticoagulation were more likely to show normal range D-dimer levels in the presence of LAT.

CONCLUSIONS

A high prevalence (42.2%) of 'normal range' D-dimer levels was found in AF patients with LAT, especially in those with hypertension, high BMI and prior anticoagulation. D-dimer levels of those patients with larger LAD were more likely to be increased.

Diagnostic accuracy of adropin as a preliminary test to exclude acute pulmonary embolism: a prospective study

Background

This study aims to investigate the diagnostic accuracy of adropin as a biomarker to exclude the diagnosis of acute pulmonary embolism (PE).

Methods

Patients admitted to the emergency department of a tertiary health centre between August 2019 and August 2020 and diagnosed with PE were included in this prospective cohort study. The amount of serum adropin was determined in patients with (PE) and compared with that of healthy volunteers. Receiver operating characteristic analysis was performed with the obtained data, and the area under the curve (AUC) with a 95% confidence interval was determined. The parameters of diagnostic accuracy for PE were determined.

Results

A total of 57 participants were included in the study (28 controls and 29 PE patients). The mean adropin level in the PE group was 187.33 ± 62.40 pg/ml, which was significantly lower than that in the control group (524.06 ± 421.68 pg/ml) (p < 0.001). When the optimal adropin cut-off value was 213.78 pg/ml, the likelihood ratio of the adropin test was 3.4, and the sensitivity of the adropin test at this value was 82% with specificity of 75% (95% CI; AUC: 0.821).

Conclusion

Our results suggest that adropin may be considered for further study as a candidate marker for the exclusion of the diagnosis of PE. However, more research is required to verify and support the generalizability of our study results.

Predictive value of D-dimer and analysis of risk factors in pregnant women with suspected pulmonary embolism after cesarean section

Background

Acute pulmonary embolism (PE) is one of the leading causes of maternal mortality, and cesarean section is an established independent risk factor for PE. The diagnostic utility of D-dimer for PE in non-pregnant women has been well-established, but its role in women with suspected PE after cesarean section is unclear. Furthermore, the optimal threshold level in this patient population is unknown. Traditional D-dimer levels have low diagnostic specificity, resulting in many pregnant women being exposed to potentially harmful radiation despite negative diagnostic imaging results. This research aimed to optimize the clinical threshold for D-dimer to improve specificity while ensuring high sensitivity and to identify risk factors for PE after cesarean section.

Methods

This retrospective study of 289 women who underwent diagnostic imaging (ventilation/perfusion [V/Q] or computed tomographic pulmonary angiography [CTPA]) for suspected acute PE after cesarean delivery from 2010 to 2021 was conducted. Clinical data and laboratory indicators within 24 h postpartum including D-dimer levels were collected for analyses.

Results

The final analysis included 125 patients, among whom 33 were diagnosed with acute PE (incidence of 11.42%, 95% confidence interval 7.7–15.1). The receiver operating characteristic curve analysis suggested that a D-dimer cut-off value of 800 ng/mL had specificity of 25.26% and sensitivity of 100% for detecting PE. The cut-off value was adjusted to 1000 ng/mL with a specificity of 34.74% and a sensitivity of 96.67%. Using a D-dimer cut-off value of 800 ng/mL (instead of the conventional value of 500 ng/mL) increased the number of patients excluded from suspected PE from 9.6 to 18.4% without additional false-negative results. Of note, a history of known thrombophilia was significantly more common in patients with PE than in those without (P < 0.05). No other independent risk factors were noted in our study.

Conclusions

The D-dimer cut-off value of 800 ng/mL ensures high sensitivity and increases specificity compared to the conventional threshold of 500 ng/mL. Utilizing this higher threshold can reduce the number of unnecessary CT and subsequently unnecessary radiation exposure, in women after cesarean delivery. Prospective studies should also be conducted to verify these results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01757-3.

Three broad classifications of acute respiratory failure etiologies based on regional ventilation and perfusion by electrical impedance tomography: a hypothesis-generating study

BACKGROUND

The aim of this study was to validate whether regional ventilation and perfusion data measured by electrical impedance tomography (EIT) with saline bolus could discriminate three broad acute respiratory failure (ARF) etiologies.

METHODS

Perfusion image was generated from EIT-based impedance-time curves caused by 10 ml 10% NaCl injection during a respiratory hold. Ventilation image was captured before the breath holding period under regular mechanical ventilation. DeadSpace%, Shunt% and VQMatch% were calculated based on lung perfusion and ventilation images. Ventilation and perfusion maps were divided into four cross-quadrants (lower left and right, upper left and right). Regional distribution defects of each quadrant were scored as 0 (distribution% ≥ 15%), 1 (15% > distribution% ≥ 10%) and 2 (distribution% < 10%). Data percentile distributions in the control group and clinical simplicity were taken into consideration when defining the scores. Overall defect scores (DefectV, DefectQ and DefectV+Q) were the sum of four cross-quadrants of the corresponding images.

RESULTS

A total of 108 ICU patients were prospectively included: 93 with ARF and 15 without as a control. PaO2/FiO2 was significantly correlated with VQMatch% (r = 0.324, P = 0.001). Three broad etiologies of ARF were identified based on clinical judgment: pulmonary embolism-related disease (PED, n = 14); diffuse lung involvement disease (DLD, n = 21) and focal lung involvement disease (FLD, n = 58). The PED group had a significantly higher DeadSpace% [40(24)% vs. 14(15)%, PED group vs. the rest of the subjects; median(interquartile range); P < 0.0001] and DefectQ score than the other groups [1(1) vs. 0(1), PED vs. the rest; P < 0.0001]. The DLD group had a significantly lower DefectV+Q score than the PED and FLD groups [0(1) vs. 2.5(2) vs. 3(3), DLD vs. PED vs. FLD; P < 0.0001]. The FLD group had a significantly higher DefectV score than the other groups [2(2) vs. 0(1), FLD vs. the rest; P < 0.0001]. The area under the receiver operating characteristic (AUC) for using DeadSpace% to identify PED was 0.894 in all ARF patients. The AUC for using the DefectV+Q score to identify DLD was 0.893. The AUC for using the DefectV score to identify FLD was 0.832.

CONCLUSIONS

Our study showed that it was feasible to characterize three broad etiologies of ARF with EIT-based regional ventilation and perfusion. Further study is required to validate clinical applicability of this method. Trial registration clinicaltrials, NCT04081142. Registered 9 September 2019-retrospectively registered, https://clinicaltrials.gov/show/NCT04081142 .

Joint analysis of D-dimer, N-terminal pro b-type natriuretic peptide, and cardiac troponin I on predicting acute pulmonary embolism relapse and mortality

Previous studies on the adverse events of acute pulmonary embolism (APE) were mostly limited to single marker, and short follow-up duration, from hospitalization to up to 30 days. We aimed to predict the long-term prognosis of patients with APE by joint assessment of D-dimer, N-Terminal Pro-Brain Natriuretic Peptide (NT-ProBNP), and troponin I (cTnI). Newly diagnosed patients of APE from January 2011 to December 2015 were recruited from three hospitals. Medical information of the patients was collected retrospectively by reviewing medical records. Adverse events (APE recurrence and all-cause mortality) of all enrolled patients were followed up via telephone. D-dimer > 0.50 mg/L, NT-ProBNP > 500 pg/mL, and cTnI > 0.40 ng/mL were defined as the abnormal. Kaplan–Meier curve was used to compare the cumulative survival rate between patients with different numbers of abnormal markers. Cox proportional hazard regression model was used to further test the association between numbers of abnormal markers and long-term prognosis of patients with APE after adjusting for potential confounding. During follow-up, APE recurrence and all-cause mortality happened in 78 (30.1%) patients. The proportion of APE recurrence and death in one abnormal marker, two abnormal markers, and three abnormal markers groups were 7.69%, 28.21%, and 64.10% respectively. Patients with three abnormal markers had the lowest survival rate than those with one or two abnormal markers (Log-rank test, P < 0.001). After adjustment, patients with two or three abnormal markers had a significantly higher risk of the total adverse event compared to those with one abnormal marker. The hazard ratios (95% confidence interval) were 6.27 (3.24, 12.12) and 10.7 (4.1, 28.0), respectively. Separate analyses for APE recurrence and all-cause death found similar results. A joint test of abnormal D-dimer, NT-ProBNP, and cTnI in APE patients could better predict the long-term risk of APE recurrence and all-cause mortality.

Derivation and validation of a nomogram model for pulmonary thromboembolism in patients undergoing lung cancer surgery

Background

A specific risk-stratification tool is needed to facilitate safe and cost-effective approaches to the prophylaxis of acute pulmonary thromboembolism (PTE) in lung cancer surgery patients. This study aimed to develop and validate a simple nomogram model for the prediction of PTE after lung cancer surgery using readily obtainable clinical characteristics.

Methods

A total of 14,427 consecutive adult patients who underwent lung cancer surgery between January 2015 and July 2018 in our institution were retrospectively reviewed. Included in the cohort were 136 patients who developed PTE and 544 non-PTE patients. The patients were randomly divided into the derivation group (70%, 95 PTE patients and 380 non-PTE patients) and the validation group (30%, 41 PTE patients and 164 non-PTE patients). A nomogram model was developed based on the results of multivariate logistic analysis in the derivation group. The cut-off values were defined using Youden's index. The prognostic accuracy was measured by area under the curve (AUC) values.

Results

In the derivation group, multivariate logistic analysis was carried out to evaluate the risk score. The risk assessment model contained five variables: age [95% confidence interval (CI): 1.008-1.083, P=0.016], body mass index (95% CI: 1.077-1.319, P=0.001), operation time (95% CI: 1.002-1.014, P=0.008), the serum level of cancer antigen 15-3 (CA15-3) before surgery (95% CI: 1.019-1.111, P=0.005), and the abnormal results of compression venous ultrasonography before surgery (95% CI: 2.819-18.838, P<0.001). All of them were independent risk factors of PTE. To simplify the risk assessment model, a nomogram model was established, which showed a good predictive performance in the derivation group (AUC 0.792, 95% CI: 0.734-0.853) and in the validation group (AUC 0.813, 95% CI: 0.737-0.890).

Conclusions

A high-performance nomogram was established on the risk factors for PTE in patients undergoing lung cancer surgery. The nomogram could be used to provide an individual risk assessment and guide prophylaxis decisions for patients. Further external validation of the model is needed in lung cancer surgery patients in other clinical centers.

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.

Nano-Medicine for Thrombosis: A Precise Diagnosis and Treatment Strategy

Thrombosis is a global health issue and one of the leading factors of death. However, its diagnosis has been limited to the late stages, and its therapeutic window is too narrow to provide reasonable and effective treatment. In addition, clinical thrombolytics suffer from a short half-life, allergic reactions, inactivation, and unwanted tissue hemorrhage. Nano-medicines have gained extensive attention in diagnosis, drug delivery, and photo/sound/magnetic-theranostics due to their convertible properties. Furthermore, diagnosis and treatment of thrombosis using nano-medicines have also been widely studied. This review summarizes the recent advances in this area, which revealed six types of nanoparticle approaches: (1) in vitro diagnostic kits using "synthetic biomarkers"; (2) in vivo imaging using nano-contrast agents; (3) targeted drug delivery systems using artificial nanoparticles; (4) microenvironment responsive drug delivery systems; (5) drug delivery systems using biological nanostructures; and (6) treatments with external irradiation. The investigations of nano-medicines are believed to be of great significance, and some of the advanced drug delivery systems show potential applications in clinical theranotics.