Evaluation and management of the acutely dyspneic patient: the role of biomarkers

Decoding Pulmonary Embolism: Pathophysiology, Diagnosis, and Treatment

Pulmonary Embolism (PE) is a life-threatening condition initiated by the presence of blood clots in the pulmonary arteries, leading to severe morbidity and mortality. Underlying mechanisms involve endothelial dysfunction, including impaired blood flow regulation, a pro-thrombotic state, inflammation, heightened oxidative stress, and altered vascular remodeling. These mechanisms contribute to vascular diseases stemming from PE, such as recurrent thromboembolism, chronic thromboembolic pulmonary hypertension, post-thrombotic syndrome, right heart failure, and cardiogenic shock. Detailing key risk factors and utilizing hemodynamic stability-based categorization, the review aims for precise risk stratification by applying established diagnostic tools and scoring systems. This article explores both conventional and emerging biomarkers as potential diagnostic tools. Additionally, by synthesizing existing knowledge, it provides a comprehensive outlook of the current enhanced PE management and preventive strategies. The conclusion underscores the need for future research to improve diagnostic accuracy and therapeutic effectiveness in PE.

Research progress on biomarkers of pulmonary embolism

OBJECTIVES

To present a review on the traditional and new biomarkers of pulmonary embolism (PE).

DATA SOURCE

A systematic search has been carried out using keywords as PE, biomarker, diagnosis and risk stratification.

RESULTS

The results of this work have been structured into three parts: first, conventional biomarkers for vascular, cardiac and inflammation, including static markers and dynamic markers for measuring the time course; next, a review of new biomarkers in recent years, such as RNAs and markers obtained through proteomics and mass spectrometry; finally, use of new detection methods to directly detect the activity of existing markers, such as the determination of coagulation factor II and plasmin activities based on the proteolytic activation of an engineered zymogen.

CONCLUSIONS

This work summarized the characteristics of current traditional biomarkers for clinical diagnosis and risk stratification of PE, as well as a series of newly discovered biomarkers obtained through various clinical experimental methods.

Serum Cortisol as a Predictor of Major Adverse Pulmonary Event in Emergency Department Acutely Dyspneic Patients

Cortisol is a steroid hormone released from the adrenal glands in response to stressful conditions. Elevated cortisol levels have been described in stress, but it is unclear whether these are associated with adverse outcomes. In this study, we assess whether cortisol levels drawn in patients presenting with dyspnea to the ED were a predictor of major adverse pulmonary event (MAPE). In 87 patients presenting with dyspnea to the ED, cortisol levels were determined. Patients were then assessed to determine the following MAPE: endotracheal intubation (ETI) in the ED, admission to the intensive care unit (ICU), and in-hospital all-cause mortality. Forty-four patients (50.6%) were female and 33 (37.9%) were diagnosed with heart failure. Cortisol levels in patients with and without MAPE were 34.3μg/dL and 23.8μg/dL, respectively (p<0.001). Also, cortisol levels were found higher in patients intubated in the ED than nonintubated patients (54.2μg/dL vs 25.7μg/dL, p<0.001), higher in patients admitted to the ICU (38.7μg/dL vs 24 μg/dL, p<0.001), and higher in patients who died in hospital (50μg/dL vs 24.3μg/dL, p<0.001). The area under the ROC curve using cortisol to detect any component of MAPE—ETI or ICU admission or in-hospital all-cause mortality—was 0.76 (95% CI, 0.65-0.84). A cortisol value of 31.4μg/dL had sensitivity of 70.8% and specificity of 79.4% for predicting MAPE. Patients in the MAPE group had higher serum cortisol levels than those without any MAPE. Cortisol may be used as a marker to predict MAPE in nontraumatic acutely dyspneic adult patients on ED admission.

Point-of-care testing in primary care patients with acute cardiopulmonary symptoms: a systematic review

BACKGROUND

Point-of-care tests (POCT) can assist general practitioners (GPs) in diagnosing and treating patients with acute cardiopulmonary symptoms, but it is currently unknown if POCT impact relevant clinical outcomes in these patients.

OBJECTIVE

To assess whether using POCT in primary care patients with acute cardiopulmonary symptoms leads to more accurate diagnosis and impacts clinical management.

METHODS

We performed a systematic review in four bibliographic databases. Articles published before February 2016 were screened by two reviewers. Studies evaluating the effect of GP use of POCT on clinical diagnostic accuracy and/or effect on treatment and referral rate in patients with cardiopulmonary symptoms were included.

RESULTS

Our search yielded nine papers describing data from seven studies, on the clinical diagnostic accuracy of POCT in a total of 2277 primary care patients with acute cardiopulmonary symptoms. Four papers showed data on GP use of D-dimer POCT in pulmonary embolism (two studies); two studies on Troponin T in acute coronary syndrome; one on heart-type fatty acid-binding protein (H-FABP) in acute coronary syndrome; one on B-type natriuretic peptide (BNP) in heart failure; one on 3-in-1 POCT (Troponin T, BNP, D-dimer) in acute coronary syndrome, heart failure and/or pulmonary embolism. Only one study assessed the effect of GP use of POCT on treatment initiation and one on actual referral rates.

CONCLUSION

There is currently limited and inconclusive evidence that actual GP use of POCT in primary care patients with acute cardiopulmonary symptoms leads to more accurate diagnosis and affects clinical management. However, some studies show promising results, especially when a POCT is combined with a clinical decision rule.

In-hospital and long-term outcomes of congestive heart failure: Predictive value of B-type and amino-terminal pro-B-type natriuretic peptides and their ratio

Relative changes in B-type natriuretic peptide (BNP) and amino terminal pro-BNP (NT-proBNP) levels may help to assess the risk of congestive heart failure (CHF). However, whether these levels at the time of admission enable the prediction of outcomes with acute exacerbation remains unknown. The current study determined the abilities of BNP, NT-proBNP and their ratio to predict in-hospital and long-term outcomes of patients with CHF. Patients who were admitted to the cardiac care unit of Juntendo University Hospital (Tokyo, Japan) with acute CHF onset were consecutively enrolled into the present observational study. Serum levels of BNP and NT-proBNP were immediately measured on admission, and other biomarkers and clinical data were also investigated. Of 195 enrolled patients, 16 (8.2%) succumbed to CHF in hospital and 124 (69.3%) reached the endpoint of mortality or readmission following a median follow-up of 14 months. Multiple linear regression analysis revealed body mass index, low density lipoprotein cholesterol, hemoglobin, estimated glomerular filtration rate and C-reactive protein as independent predictors of the NT-proBNP/BNP ratio. BNP, NT-proBNP and their ratio were significantly higher among those who succumbed to CHF than in those who remained alive in hospital (P<0.05). Logistic regression analysis indicated that the ratio was an independent predictor for in-hospital mortality and long-term outcomes. In conclusion, the ratio of NT-proBNP to BNP more effectively predicts in-hospital outcomes than either factor alone and it may also help to predict outcomes among patients with acute exacerbation of HF.

Determining the cause of dyspnoea: linguistic and biological descriptors

Dyspnoea is the most common symptom of patients with cardio-respiratory diseases. It is a generic term related to different pathophysiological abnormalities that may result in different qualities of respiratory discomfort, defined by specific verbal descriptors for a specific diagnosis. Often it is difficult to distinguish the underlying pathology of dyspnoea, eg, either from chronic heart failure (CHF) or from other respiratory causes. The discovery of the endocrine function of the heart, as well as the development of accurate and feasible assay methods allow the use of cardiac natriuretic hormones in the assessment of cardiovascular diseases, namely acute coronary syndromes and heart failure. It is advisable to measure cardiac natriuretic hormones in order to exclude or suggest the diagnosis of CHF in patients with a suspicious diagnosis, but with ambiguous signs and symptoms or manifestations that can be confused with other pathologies (like chronic obstructive pulmonary disease). The most common symptom of patients with cardio-respiratory diseases is dyspnoea, a 'difficult, laboured, uncomfortable breathing'. Dyspnoea has been defined as 'a term used to characterize a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity. The experience derives from interactions among multiple physiological, psychological, social and environmental factors, and may induce secondary physiological and behavioural responses'. Breathlessness is characterized by measurable intensity and qualitative dimensions, which may vary depending on the individual, the underlying disease, and other circumstances.3 The neurophysiological basis of dyspnoea relies on receptors in the airways lung parenchyma, respiratory muscles together with chemoreceptors providing sensory feedback via vagal, phrenic and intercostal nerves to the spinal cord, medulla and higher centres. Breathlessness is based on different pathophysiolagical abnormalities that may result in different qualities of respiratory discomfort, which are defined by specific verbal descriptors related to a specific diagnosis. Nevertheless different diseases may share the same descriptors. There is no clear relationship between the qualitative descriptors of dyspnoea and the quantitative intensity among the patient groups: different diseases may be distinguished by quality but not intensity of the sensation. Differences in languages, in races, cultures, gender, and in the manner in which concepts or symptoms are held can all influence the idea, quality and intensity of dyspnoea.

Cardiac safety of diclofenac at a single dose in ram

Nonsteroidal anti-inflammatory drugs are frequently prescribed drug group in human and veterinary medicine. However, diclofenac, a traditional nonsteroidal anti-inflammatory drug, related to cardiotoxicity is reported, and blood cardiac damage markers may increase within the first hours after damage. The aim of the current research was to determine the effect of diclofenac on the blood cardiac damage markers. Single dose of diclofenac (2.5 mg/kg, IM) was injected to 6 rams. Blood samples were collected in before (0 hour, control) and 6 hours after injection. Specific (troponin I, and creatine kinase-MB) and nonspecific (lactate dehydrogenase, aspartate aminotransferase) blood cardiac damage marker concentrations, routine biochemical (hepatic damage, renal damage, lipid metabolism, glucose, and phosphorus) parameters, and hemogram values were measured. Diclofenac increased (P < 0.05) specific (troponin I) and nonspecific cardiac (lactate dehydrogenase, aspartate aminotransferase), hepatic (aspartate aminotransferase, alkaline phosphatase, and alanine aminotransferase), and muscular (creatine kinase) damage markers and high density lipoprotein level, while it decreased (P < 0.05) low density lipoprotein level. Moreover, diclofenac decreased (P < 0.05) white blood cell counts and increased (P < 0.05) red blood cell counts. In conclusion, it may be stated that diclofenac shows slight cardiotoxicity, whereas it may show potent hepatic and muscular damage effects at an intramuscularly single dose in sheep. Thereby, repeated injections of diclofenac may be more harmful in sheep.

Revisiting signs, strengths and weaknesses of Standard Chest Radiography in patients of Acute Dyspnea in the Emergency Department

Dyspnoea, defined as an uncomfortable awareness of breathing, together with thoracic pain are two of the most frequent symptoms of presentation of thoracic diseases in the Emergency Department (ED). Causes of dyspnoea are various and involve not only cardiovascular and respiratory systems. In the emergency setting, thoracic imaging by standard chest X-ray (CXR) plays a crucial role in the diagnostic process, because it is of fast execution and relatively not expensive. Although radiologists are responsible for the final reading of chest radiographs, very often the clinicians, and in particular the emergency physicians, are alone in the emergency room facing this task. In literature many studies have demonstrated how important and essential is an accurate direct interpretation by the clinician without the need of an immediate reading by the radiologist. Moreover, the sensitivity of CXR is much impaired when the study is performed at bedside by portable machines, particularly in the diagnosis of some important causes of acute dyspnoea, such as pulmonary embolism, pneumothorax, and pulmonary edema. In these cases, a high inter-observer variability of bedside CXR reading limits the diagnostic usefulness of the methodology and complicates the differential diagnosis. The aim of this review is to analyze the radiologic signs and the correct use of CXR in the most important conditions that cause cardiac and pulmonary dyspnoea, as acute exacerbation of chronic obstructive pulmonary disease, acute pulmonary oedema, acute pulmonary trombo-embolism, pneumothorax and pleural effusion, and to focus indications and limitations of this diagnostic tool.

Diagnostic accuracy of point-of-care testing for acute coronary syndromes, heart failure and thromboembolic events in primary care: a cluster-randomised controlled trial

Background

Evidence of the clinical benefit of 3-in-1 point-of-care testing (POCT) for cardiac troponin T (cTnT), N-terminal pro-brain natriuretic peptide (NT-proBNP) and D-dimer in cardiovascular risk stratification at primary care level for diagnosing acute coronary syndromes (ACS), heart failure (HF) and thromboembolic events (TE) is very limited. The aim of this study is to analyse the diagnostic accuracy of POCT in primary care.

Methods

Prospective multicentre controlled trial cluster-randomised to POCT-assisted diagnosis and conventional diagnosis (controls). Men and women presenting in 68 primary care practices in Zurich County (Switzerland) with chest pain or symptoms of dyspnoea or TE were consecutively included after baseline consultation and working diagnosis. A follow-up visit including confirmed diagnosis was performed to determine the accuracy of the working diagnosis, and comparison of working diagnosis accuracy between the two groups.

Results

The 218 POCT patients and 151 conventional diagnosis controls were mostly similar in characteristics, symptoms and pre-existing diagnoses, but differed in working diagnosis frequencies. However, the follow-up visit showed no statistical intergroup difference in confirmed diagnosis frequencies. Working diagnoses overall were significantly more correct in the POCT group (75.7% vs 59.6%, p = 0.002), as were the working diagnoses of ACS/HF/TE (69.8% vs 45.2%, p = 0.002). All three biomarker tests showed good sensitivity and specificity.

Conclusion

POCT confers substantial benefit in primary care by correctly diagnosing significantly more patients.

Trial registration

DRKS: DRKS00000709

Electrochemical immunoanalysis of cardiac myoglobin

Method targeting the direct monitoring of myoglobin based on analysis of electrochemical parameters of modified electrodes were proposed. Method of direct detection is based on interaction of myoglobin with anti-myoglobin with subsequent electrochemical registration of hemeprotien. Myocardial infarction biomarker myoglobin was quantified at biological level using screen printed electrodes modified with gold nanoparticles stabilized with didodecyldimethylammonium bromide (DDAB) and antibodies. Proposed method did not require signal enhancement and amplification and also labeled secondary antibodies. Electro analysis has high specificity and sensitivity. Myoglobin -antibodies interaction was studied also with electrochemical impedance spectroscopy. Sensor has low detection limit and broad diapason of working concentrations (17.8 ng/ml - 1780 ng/ml; 1 nM - 10 nM). Method based on gold nanoparticles detection on the surface of electrodes was treated for myoglobin identification. AuNP worked as an electrochemical sensing platform: the oxidation of gold surface (resulted in gold oxide formation) upon polarization served as a basis for analytical response. The difference of cathodic peak area and peak high of gold oxide reduction in the case of electrodes with antibodies and electrodes with antibodies - myoglobin complex, was registered.

Electrochemical nanobiosensor for express diagnosis of acute myocardial infarction in undiluted plasma

The myocardial infarction biomarker myoglobin was quantified at the biological level in undiluted plasma using developed electrochemical nanosensors with immobilized anti-myoglobin. Method for cardiac myoglobin detection is based on direct electron transfer between Fe(III)-heme and electrode surface modified with gold nanoparticles/didodecyldimethylammonium bromide (DDAB/Au) and antibodies. The procedure of myoglobin detection was optimized (pH, incubation times and characteristics of electrodes) to express determination of the marker in serum or plasma. Plasma of healthy donors and patients with acute myocardial infarction (AMI) was analyzed using electrochemical immunosensors and RAMP immunoassay. Square wave voltammetry cathodic peak of cardiac myoglobin reduction was found to be proportional to myoglobin quantity in plasma as determined by RAMP. The method proposed does not require signal enhancement or amplification; nor does it require labeled secondary antibodies. Immunosensor has a detection limit of 10 ng/ml (0.56 nM) and a broad range of working concentrations (10-1780 ng/ml; 0.56-100 nM). The whole procedure takes 30 min and can be used for express diagnosis of acute myocardial infarction.

D-dimer levels correlate with mortality in patients with acute pulmonary embolism: Findings from the RIETE registry

OBJECT

Few studies have addressed the prognostic implications of D-dimer in patients with pulmonary embolism. The aim of this study was to investigate the correlation between D-dimer levels and mortality in patients with pulmonary embolism.

DESIGN

Observational study.

SETTING

Hospitals participating in the Registro Informatizado de la Enfermedad Tromboembólica (RIETE).

PATIENTS

A total of 588 consecutive patients with symptomatic pulmonary embolism who were included in the RIETE between March 2001 and December 2004.

INTERVENTIONS

Quantitative D-dimer measurement was performed on admission using an automated latex agglutination test (IL Test D-dimer). All patients underwent clinical follow-up for 3 months.

MEASUREMENTS AND MAIN RESULTS

Overall mortality rate was 10.5%. The cause of death was pulmonary embolism in 18 patients (3.0%), fatal bleeding in one patient (0.2%), and other causes in 43 patients (7.3%). There were 28 (4.8%) nonfatal venous thromboembolism recurrences and 35 (6.0%) nonfatal bleeding episodes. The incidence of D-dimer 500-2499 ng/mL, D-dimer 2500-4999 ng/mL, and D-dimer >or=5000 ng/mL was 47.8%, 26.0%, and 20.4%, respectively. Compared with patients with D-dimer 500-2499 ng/mL, the relative risk (odds ratio) of overall mortality was 1.91 (95% confidence interval 0.91-4.09) and 2.94 (95% confidence interval 1.42-6.25) in patients with D-dimer 2500-4999 ng/mL and D-dimer >or= 5000 ng/mL, respectively (p = .032). Patients with D-dimer >or=5000 ng/mL showed higher risk of death from fatal pulmonary embolism (odds ratio 4.4, 95% confidence interval 0.5-33.0) than death from other causes (odds ratio 2.1, 95% confidence interval 0.7-6.0). Elevated D-dimer levels were associated with more severe disease, as assessed by clinical features.

CONCLUSIONS

In patients who present with pulmonary embolism, D-dimer concentration is an independent predictive factor associated with all-cause and pulmonary embolism-related death. D-dimer >or=5000 ng/mL occurs in about one in five patients and is associated with a 2.9-fold increased risk of overall mortality. These results suggest that D-dimer quantification could be a useful biomarker and help determine initial therapies.