Brain-type natriuretic peptide levels in the prediction of adverse outcome in patients with pulmonary embolism: a systematic review and meta-analysis

Unloading of right ventricle and clinical improvement after ultrasound-accelerated thrombolysis in patients with submassive pulmonary embolism

Acute pulmonary embolism (PE) can be devastating. It is classified into three categories based on clinical scenario, elevated biomarkers, radiographic or echocardiographic features of right ventricular strain, and hemodynamic instability. Submassive PE is diagnosed when a patient has elevated biomarkers, CT-scan, or echocardiogram showing right ventricular strain and no signs of hemodynamic compromise. Thromboemboli in the acute setting increase pulmonary vascular resistance by obstruction and vasoconstriction, resulting in pulmonary hypertension. This, further, deteriorates symptoms and hemodynamic status. Studies have shown that elevated biomarkers and right ventricular (RV) dysfunction have been associated with increased risk of mortality. Therefore, aggressive treatment is necessary to “unload” right ventricle. The treatment of submassive PE with thrombolysis is controversial, though recent data have favored thrombolysis over conventional anticoagulants in acute setting. The most feared complication of systemic thrombolysis is intracranial or major bleeding. To circumvent this problem, a newer and safer approach is sought. Ultrasound-accelerated thrombolysis is a relatively newer and safer approach that requires local administration of thrombolytic agents. Herein, we report a case series of five patients who underwent ultrasound-accelerated thrombolysis with notable improvement in symptoms and right ventricular function.

Clinical update on pulmonary embolism

Pulmonary embolism (PE) is a major cause of cardiovascular mortality and financial burden that affects the community. The diagnosis of PE can be difficult because of the nonspecific symptoms, which include cough, dyspnea, hemoptysis and pleuritic chest pain. Hereditary and acquired risk factors are associated with PE. Incidence of PE is increasing, associated with the development in the diagnostic methods. Evidence-based algorithms can help clinicians diagnose PE. Serum D-dimer level, computed tomography pulmonary angiogram (CTPA), ventilation-perfusion scintigraphy or echocardiography help to establish clinical probability and the severity of PE. Anticoagulation is the standard treatment for PE. However, thrombolytic treatment is a significant alternative in high risk of PE as it provides rapid clot resolution. This article reviews the risk factors, diagnostic algorithms, and methods of treatment in PE in the light of current information.

Predicting the risk of venous thromboembolism in patients hospitalized with heart failure

BACKGROUND

Whether heart failure (HF) increases the risk of venous thromboembolism (VTE) is not well established. In the phase III MAGELLAN (Multicenter, rAndomized, parallel Group Efficacy and safety study for the prevention of venous thromboembolism in hospitalized medically iLL patients comparing rivaroxabAN with enoxaparin) trial, extended-duration rivaroxaban was compared with standard-duration enoxaparin followed by placebo for VTE prevention in 8101 hospitalized acutely ill patients with or without HF. The aim of this analysis was to evaluate the relationship between HF severity and the risk of VTE in MAGELLAN patients.

METHODS AND RESULTS

Hospitalized patients diagnosed with HF were included according to New York Heart Association class III or IV at admission (n=2593). HF severity was determined by N-terminal probrain natriuretic peptide (NT-proBNP) plasma concentrations (median 1904 pg/mL). Baseline plasma D-dimer concentrations ranged from 0.6 to 1.7 μg/L for the less and more severe HF subgroups. Patients with more severe HF had a greater incidence of VTE versus patients with less severe HF, with a significant trend up to Day 10 (4.3% versus 2.2%; P=0.0108) and Day 35 (7.2% versus 4.1%; P=0.0150). Multivariable analysis confirmed that NT-proBNP concentration was associated with VTE risk up to Day 10 (P=0.017) and D-dimer concentration with VTE risk up to Day 35 (P=0.005). The association between VTE risk and HF severity that was observed in the enoxaparin/placebo group was not seen in the extended-duration rivaroxaban group.

CONCLUSIONS

Patients with more severe HF, as defined by high NT-proBNP plasma concentration, were at increased risk of VTE. NT-proBNP may be useful to identify high short-term risk, whereas elevated D-dimer may be suggestive of high midterm risk.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00571649.

The usefulness of gated blood pool scintigraphy for right ventricular function evaluation in pulmonary embolism patients

OBJECTIVE

According to the international registry ICOPER, right ventricular (RV) dysfunction is the most significant predictor of mortality in patients with pulmonary embolism (PE).

AIM

To identify the most informative indicators of gated blood pool single photon emission computer tomography (GBP-SPECT) for evaluation of RV function in patients with PE.

METHODS

A total of 52 patients were included in the study. The main group (n = 37) comprised patients with PE, and the comparison group (n = 15) patients suffering from coronary heart disease (NYHA class I-II). All patients received GBP-SPECT, and assessment of plasma levels of endothelin-1, stable nitric oxide (NO) metabolites, and 6-keto-PG F1α.

RESULTS

In patients with PE, RV end-systolic volume, stroke volume, ejection fraction, peak ejection rate, peak filling rate, and mean filling rate were significantly lower in comparison with patients without PE. In patients with PE, the levels of endothelin-1, 6-keto-PG F1α, and stable NO metabolites were increased in comparison with patients without PE.

CONCLUSIONS

GBP-SPECT facilitates verification of RV dysfunction in patients without massive PE or severe pulmonary hypertension. Dissociation between the volume of PE and degree of RV dysfunction may be caused by an unbalance between humoral vasoactive factors.

A novel H-FABP assay and a fast prognostic score for risk assessment of normotensive pulmonary embolism

We tested whether heart-type fatty acid binding protein (H-FABP) measured by a fully-automated immunoturbidimetric assay in comparison to ELISA provides additive prognostic value in patients with pulmonary embolism (PE), and validated a fast prognostic score in comparison to the ESC risk prediction model and the simplified Pulmonary Embolism Severity Index (sPESI). We prospectively examined 271 normotensive patients with PE; of those, 20 (7%) had an adverse 30-day outcome. H-FABP levels determined by immunoturbidimetry were higher (median, 5.2 [IQR; 2.7-9.8] ng/ml) than those by ELISA (2.9 [1.1-5.4] ng/ml), but Bland-Altman plot demonstrated a good agreement of both assays. The area under the curve for H-FABP was greater for immunoturbidimetry than for ELISA (0.82 [0.74-0.91] vs 0.78 [0.68-0.89]; P=0.039). H-FABP measured by immunoturbidimetry (but not by ELISA) provided additive prognostic information to other predictors of 30-day outcome (OR, 12.4 [95% CI, 1.6-97.6]; P=0.017). When H-FABP determined by immunoturbidimetry was integrated into a novel prognostic score (H-FABP, Syncope, and Tachycardia; FAST score), the score provided additive prognostic information by multivariable analysis (OR, 14.2 [3.9-51.4]; p<0.001; c-index, 0.86) which were superior to information obtained by the ESC model (c-index, 0.62; net reclassification improvement (NRI), 0.39 [0.21-0.56]; P<0.001) or the sPESI (c-index, 0.68; NRI, 0.24 [0.05-0.43]; P=0.012). In conclusion, determination of H-FABP by immunoturbidimetry provides prognostic information superior to that of ELISA and, if integrated in the FAST score, appears more suitable to identify patients with an adverse 30-day outcome compared to the ESC model and sPESI.

The predictive value of heart-type fatty acid-binding protein is independent from symptom duration in normotensive patients with pulmonary embolism

BACKGROUND

Heart-type fatty acid-binding protein (H-FABP) is a useful biomarker for risk stratification of patients with pulmonary embolism (PE). In patients with acute myocardial infarction, H-FABP plasma concentrations rise after 30 minutes and return to normal within 20-24 hours. We tested whether the predictive value of H-FABP is affected by the duration of symptoms prior to diagnosis in patients with PE.

MATERIAL AND METHODS

We prospectively studied 257 consecutive normotensive patients with confirmed symptomatic PE.

RESULTS

Patients with acute (<24 hours; n=150) symptom onset presented more often with syncope (28.7% vs. 6.5%; p<0.001) compared to patients with symptoms ≥ 24 hours (n=107); other baseline characteristics, comorbidities, and risk factors were distributed equally. Patients with an adverse 30-day outcome (6.6%) had higher H-FABP levels (11.84 [3.57-19.62] ng/ml) compared to patients with a favorable course (3.42 [1.92-5.42] ng/ml; p<0.001). However, the proportion of patients with H-FABP levels ≥ 6 ng/ml did not differ among patients with acute symptom onset and late presentation (p=0.104). Only tachycardia and elevation of H-FABP were associated with an increased risk of an adverse 30-day outcome both in patients with acute symptom onset (H-FABP: OR, 5.8; 95% CI, 1.4-24.5; p=0.016; tachycardia: 7.0 [1.4-36.0]; p=0.018) and late presentation (H-FABP: 9.3 [2.0-43.2]; p=0.004 and tachycardia: 12.3 [1.5-103.6]; p=0.021). The prognostic value could further be improved by the use of a simple H-FABP-based clinical prediction score.

CONCLUSIONS

Our findings indicate that H-FABP is a useful biomarker for risk stratification of normotensive patients with PE regardless of symptom duration prior to diagnosis.

Evaluation factors of pulmonary embolism severity and prognosis

Management of pulmonary embolism (PE) is still unclear. We summarized 16 kinds of evaluation factors of PE severity and prognosis, and we analyzed the single and joint value for short-term and long-term prognosis. Among them, biomarkers such as brain natriuretic peptide or N-terminal probrain natriuretic peptide, troponin, and heart-type fatty acid-binding protein are the best indicators of PE severity and short-term prognosis. They might replace imaging detections in evaluating PE severity. But the positive predictive value of all the biomarkers is low, and we need to improve each value through joint detection. The PE severity index and simplified PE severity index are more suitable for evaluating the overall risk and long-term prognosis. They could be used as complements of indicators of the PE severity, especially in identifying low-risk group. Integrated risk stratification and strategies of management should be established based on the 2 aspects mentioned previously.

Fluctuation of serum sodium and its impact on short and long-term mortality following acute pulmonary embolism

BACKGROUND

Baseline hyponatremia predicts acute mortality following pulmonary embolism (PE). The natural history of serum sodium levels after PE and the relevance to acute and long-term mortality after the PE is unknown.

METHODS

Clinical details of all patients (n = 1023) admitted to a tertiary institution from 2000-2007 with acute PE were retrieved retrospectively. Serum sodium results from days 1, 3-4, 5-6, and 7 of admission were pre-specified and recorded. We excluded 250 patients without day-1 sodium or had <1 subsequent sodium assessment, leaving 773 patients as the studied cohort. There were 605 patients with normonatremia (sodium≥135 mmol/L throughout admission), 57 with corrected hyponatremia (day-1 sodium<135 mmol/L, then normalized), 54 with acquired hyponatremia and 57 with persistent hyponatremia. Patients' outcomes were tracked from a state-wide death registry and analyses performed using multivariate-regression modelling.

RESULTS

Mean (±standard deviation) day-1 sodium was 138.2±4.3 mmol/L. Total mortality (mean follow-up 3.6±2.5 years) was 38.8% (in-hospital mortality 3.2%). There was no survival difference between studied (n = 773) and excluded (n = 250) patients. Day-1 sodium (adjusted hazard ratio [aHR] 0.89, 95% confidence interval [CI] 0.83-0.95, p = 0.001) predicted in-hospital death. Relative to normonatremia, corrected hyponatremia increased the risk of in-hospital death 3.6-fold (95% CI 1.20-10.9, p = 0.02) and persistent hyponatremia increased the risk 5.6-fold (95% CI 2.08-15.0, p = 0.001). Patients with either persisting or acquired hyponatremia had worse long-term survival than those who had corrected hyponatremia or had been normonatremic throughout (aHR 1.47, 95% CI 1.06-2.03, p = 0.02).

CONCLUSION

Sodium fluctuations after acute PE predict acute and long-term outcome. Factors mediating the correction of hyponatremia following acute PE warrant further investigation.

The prognostic value of pro-B-Type natriuretic peptide in acute pulmonary embolism

AIMS

To assess the clinical performance of pro-B-type natriuretic peptide 1-108 (proBNP) for the prognosis of acute pulmonary embolism.

METHODS

This study was ancillary to a recently published multicentre study including 570 patients with acute pulmonary embolism. ProBNP values were analysed using a new sandwich immunoassay proBNP1-108, Bioplex2200 (Bio-Rade Laboratories). Data was compared with BNP and N-terminal (NT) proBNP values. Adverse outcomes at 30 days were defined as death, secondary cardiogenic shock, or recurrent venous thromboembolism.

RESULTS

ProBNP values were analysed in 549 patients, with 39 (7.1%) presenting adverse outcomes. All three natriuretic peptides were significantly elevated in these 39 patients compared with the group without adverse outcomes (BNP: p < 0.001; NT-proBNP: p < 0.001; proBNP: 0.044), with median proBNP values being 605 pg/ml (113-1437) and 109 pg/ml (30-444), respectively. Multivariate analyses revealed that proBNP significantly depended on patient age (p < 0.001) and renal failure (p=0.001), with proBNP values increasing with both factors. The areas under the receiver operating curve were 0.74 (95% CI 0.69-0.79) for BNP, 0.76 (95% CI 0.72-0.80) for NT-proBNP, and 0.70 (95% CI 0.65-0.75) for proBNP, meaning that the performance of proBNP was significantly lower than that of the two other peptides (p = 0.017).

CONCLUSION

ProBNP, BNP, and NT-proBNP values were significantly increased in patients with adverse outcomes after acute pulmonary embolism. However, the prognostic performance of proBNP for predicting adverse versus favourable outcomes was lower than that of the other natriuretic peptides, thus limiting the clinical relevance of proBNP as a prognostic marker in pulmonary embolism.

New prospective for the management of low-risk pulmonary embolism: prognostic assessment, early discharge, and single-drug therapy with new oral anticoagulants

Patients with pulmonary embolism (PE) can be stratified into two different prognostic categories, based on the presence or absence of shock or sustained arterial hypotension. Some patients with normotensive PE have a low risk of early mortality, defined as <1% at 30 days or during hospital stay. In this paper, we will discuss the new prospective for the optimal management of low-risk PE: prognostic assessment, early discharge, and single-drug therapy with new oral anticoagulants. Several parameters have been proposed and investigated to identify low-risk PE: clinical prediction rules, imaging tests, and laboratory markers of right ventricular dysfunction or injury. Moreover, outpatient management has been suggested for low-risk PE: it may lead to a decrease in unnecessary hospitalizations, acquired infections, death, and costs and to an improvement in health-related quality of life. Finally, the main characteristics of new oral anticoagulant drugs and the most recent published data on phase III trials on PE suggest that the single-drug therapy is a possible suitable option. Oral administration, predictable anticoagulant responses, and few drug-drug interactions of direct thrombin and factor Xa inhibitors may further simplify PE home therapy avoiding administration of low-molecular-weight heparin.

The prognostic value of pulmonary embolism severity index in acute pulmonary embolism: a meta-analysis

BACKGROUND

Prognostic assessment is important for the management of patients with acute pulmonary embolism (APE). Pulmonary Embolism Severity Index (PESI) and simple PESI (sPESI) are new emerged prognostic assessment tools for APE. The aim of this meta-analysis is to assess the accuracy of the PESI and the sPESI to predict prognostic outcomes (all-cause and PE-related mortality, serious adverse events) in APE patients, and compare between these two PESIs.

METHODS

MEDLINE and EMBASE database were searched up to June 2012 using the terms "Pulmonary Embolism Severity Index" and "pulmonary embolism". Summary odds ratio (OR) with 95% confidence intervals (CIs) for prognostic outcomes in low risk PESI versus high risk PESI were calculated. Summary receiver operating characteristic curve (SROC) used to estimate overall predicting accuracies of prognostic outcomes.

RESULTS

Twenty-one studies were included in this meta-analysis. The results showed low-risk PESI was significantly associated with lower all-cause mortality (OR 0.13; 95% CI 0.12 to 0.15), PE-related mortality (OR 0.09; 95% CI 0.05 to 0.17) and serious adverse events (OR 0.34; 95% CI 0.29 to 0.41), with no homogeneity across studies. In sPESI subgroup, the OR of all-cause mortality, PE-related mortality, and serious adverse events was 0.10 (95% CI 0.08 to 0.14), 0.09 (95% CI 0.03 to 0.26) and 0.40 (95% CI 0.31 to 0.51), respectively; while in PESI subgroup, the OR was 0.14 (95% CI 0.13 to 0.16), 0.09 (95% CI 0.04 to 0.21), and 0.30 (95% CI 0.23 to 0.38), respectively. For accuracy analysis, the pooled sensitivity, the pooled specificity, and the overall weighted AUC for PESI predicting all-cause mortality was 0.909 (95% CI: 0.900 to 0.916), 0.411 (95% CI: 0.407 to 0.415), and 0.7853±0.0058, respectively; for PE-related mortality, it was 0.953 (95% CI: 0.913 to 0.978), 0.374 (95% CI: 0.360 to 0.388), and 0.8218±0.0349, respectively; for serious adverse events, it was 0.821 (95% CI: 0.795 to 0.845), 0.389 (95% CI: 0.384 to 0.394), and 0.6809±0.0208, respectively. In sPESI subgroup, the AUC for predicting all-cause mortality, PE-related mortality, and serious adverse events was 0.7920±0.0117, 0.8317±0.0547, and 0.6454±0.0197, respectively. In PESI subgroup, the AUC was 0.7856±0.0075, 0.8158±0.0451, and 0.6609±0.0252, respectively.

CONCLUSIONS

PESI has discriminative power to predict the short-term death and adverse outcome events in patients with acute pulmonary embolism, the PESI and the sPESI have similar accuracy, while sPESI is easier to use. However, the calibration for predicting prognosis can't be calculated from this meta-analysis, some prospective studies for accessing PESI predicting calibration can be recommended.

Use of biomarkers or echocardiography in pulmonary embolism: the Swiss Venous Thromboembolism Registry

BACKGROUND

Cardiac biomarkers and echocardiography for assessing right ventricular function are recommended to risk stratify patients with acute non-massive pulmonary embolism (PE), but it remains unclear if these tests are performed systematically in daily practice.

DESIGN AND METHODS

Overall, 587 patients with acute non-massive PE from 18 hospitals were enrolled in the Swiss Venous Thromboembolism Registry (SWIVTER): 178 (30%) neither had a biomarker test nor an echocardiographic evaluation, 196 (34%) had a biomarker test only, 47 (8%) had an echocardiogram only and 166 (28%) had both tests.

RESULTS

Among the 409 (70%) patients with biomarkers or echocardiography, 210 (51%) had at least one positive test and 67 (16%) had positive biomarkers and right ventricular dysfunction. The ICU admission rates were 5.1% without vs. 5.6% with testing (P = 0.78), and thrombolysis or embolectomy were performed in 2.8% vs. 4.9%, respectively (P = 0.25). In multivariate analysis, syncope [odds ratio (OR): 3.49, 95% confidence interval (CI): 1.20-10.15; P = 0.022], tachycardia (OR: 2.31, 95% CI: 1.37-3.91; P = 0.002) and increasing age (OR: 1.02; 95% CI: 1.01-1.04; P < 0.001) were associated with testing of cardiac risk; outpatient status at the time of PE diagnosis (OR: 2.24, 95% CI: 1.49-3.36; P < 0.001), cancer (OR: 1.81, 95% CI: 1.17-2.79; P = 0.008) and provoked PE (OR: 1.58, 95% CI: 1.05-2.40; P = 0.029) were associated with its absence.

CONCLUSION

Although elderly patients and those with clinically severe PE were more likely to receive a biomarker test or an echocardiogram, these tools were used in only two-thirds of the patients with acute non-massive PE and rarely in combination.

A simple score for rapid risk assessment of non-high-risk pulmonary embolism

OBJECTIVE

We tested whether bedside testing for H-FABP is, alone or integrated in combination models, useful for rapid risk stratification of non-high-risk PE.

METHODS

We prospectively studied 136 normotensive patients with confirmed PE. H-FABP was determined using a qualitative bedside-test showing a positive result for plasma concentration >7 ng/ml.

RESULTS

Overall, 11 patients (8.1 %) had an adverse 30-day outcome. Of 58 patients (42.6 %) with a positive H-FABP bedside-test, 9 (15.5 %) had an unfavourable course compared to 2 of 78 patients (2.6 %) with a negative test result (p = 0.009). Logistic regression analysis indicated a sevenfold increased risk for an adverse outcome (95 % CI, 1.45-33.67; p = 0.016) for patients with a positive H-FABP bedside-test. Additive prognostic information were obtained by a novel score including the H-FABP bedside-test (1.5 points), tachycardia (2 points), and syncope (1.5 points) (OR 11.57 [2.38-56.24]; p = 0.002 for ≥3 points). Increasing points were associated with a continuous exponential increase in the rate of an adverse 30-day outcome (0 % for patients with 0 points and 44.4 % for ≥5 points). Notably, this simple score provided similar prognostic value as the combination of the H-FABP bedside-test with echocardiographic signs of right ventricular dysfunction (OR 12.73 [2.51-64.43]; p = 0.002).

CONCLUSIONS

Bedside testing for H-FABP appears a useful tool for immediate risk stratification of non-high-risk patients with acute PE, who may be at increased risk of an adverse outcome, in particular if integrated in a novel score without the need of echocardiographic examination.

Prognostic clinical prediction rules to identify a low-risk pulmonary embolism: a systematic review and meta-analysis

BACKGROUND

Prognostic assessment is important for the management of patients with a pulmonary embolism (PE). A number of clinical prediction rules (CPRs) have been proposed for stratifying PE mortality risk. The aim of this systematic review was to assess the performance of prognostic CPRs in identifying a low-risk PE.

METHODS

MEDLINE and EMBASE databases were systematically searched until August 2011. Derivation and validation studies that assessed the performance of prognostic CPRs in predicting adverse events-risk in PE patients were included. Weighted mean proportion and 95% confidence intervals (CIs) of adverse events were then calculated and pooled using a fixed and a random-effects model. Statistical heterogeneity was evaluated through the use of I(2) statistics.

RESULTS

Of 1125 references in the original search, 33 relevant articles were included. Nine CPRs were assessed in 37 cohorts, for a total of 35,518 patients. Pulmonary Embolism Severity Index and prognostic Geneva CPR were investigated in 22 and 6 cohorts, respectively. Eleven (29.7%) cohorts were of high quality. The median follow-up was 30 days. In low-risk PE patients, pooled short-term mortality (within 14 days or less) was 0.7% (95% CI 0.3-1.1%, random-effects model; I(2) = 49.6%), 30-day mortality was 1.7% (95% CI 1.1-2.3%, random-effects model; I(2) = 82.4%) and 90-day mortality was 2.2% (95% CI 1.2-3.4%, random-effects model; I(2) = 59.8%).

CONCLUSIONS

Prognostic CPRs efficiently identify PE patients at a low risk of mortality. Before implementing prognostic CPRs in the routine care of PE patients, well-designed management studies are warranted.

Residual pulmonary thromboemboli after acute pulmonary embolism

BACKGROUND

After an acute pulmonary embolism (PE), the complete resolution of thromboemboli may not be routinely achieved. The rate of persistence may depend on the time and the diagnostic technique used for evaluation.

PATIENTS AND METHODS

Patients were diagnosed with acute PE by means of computed tomography angiography (CTA). While they were receiving anticoagulant therapy, a second CTA was used to explore the rate of persistence of residual thromboemboli. During the initial episode, the plasma levels of Troponin I and natriuretic peptide, patient demographics, and hemodynamic and gas exchange data were evaluated as risk factors for persistence of pulmonary thromboemboli.

RESULTS

In this study 166 patients were diagnosed. A second CTA was not made in 46 (28%) patients for different reasons. In 120 (72%) patients a second CTA was made 4.5 [SD2.34] months after the initial episode (range 2-12 months). Complete clearance of thrombi occurred in 89 (74%, 95% CI 65-81) patients. Residual thrombi remained in 31 (26%, 95% CI 18-34) patients. In 6%, 13% and 81% of the patients the size of the residual thrombi was greater, similar to and smaller than initially diagnosed, respectively. The risk factors for residual thrombi included the thrombotic burden (OR 1.95), the alveolar to arterial difference of oxygen (OR 1.64), and the clinical antecedents of venous thromboembolic disease (OR 0.65).

CONCLUSIONS

After 4.5 months of anticoagulant therapy, residual pulmonary thromboemboli persisted in 26% of the patients. The risk factors for residual thromboemboli include a greater initial thrombotic burden, a deeper gas exchange disturbation and a history of previous venous thromboembolism.

Care of patients with acute pulmonary emboli: a clinical review with cardiovascular focus

Acute pulmonary embolism (PE) is a common, multidisciplinary disease with substantial associated morbidity, mortality and healthcare expense. In this article we present a succinct review of diagnostic tools, risk stratification and medical therapies for cardiovascular care of patients with acute PE. While pulmonary angiography remains the 'gold standard' for diagnosis, a host of diagnostic modalities, interpreted in the setting of clinical probability, are available for patient assessment, including ECG, chest radiography, D-dimer, lower-extremity venous ultrasound, ventilation-perfusion scans, computed tomography and magnetic resonance angiography, and echocardiography, each with associated value. Diagnostic algorithms incorporate multiple tools in order to obtain a more comprehensive evaluation. Therapeutic anticoagulation remains the mainstay of therapy in PE. In massive PE, utilization of thrombolysis is reasonable in the absence of contraindications. Submassive PE, characterized by right ventricular dysfunction as assessed by echocardiography and ECG, is associated with higher mortality. Use of thrombolysis in submassive PE remains controversial. Catheter-directed therapies are emerging as an added approach to acute PE and have the potential to improve outcomes in PE. Use of inferior vena cava filters should be pursued in a select patient population as they serve to reduce recurrent acute PE; however, they are associated with more frequent deep venous thrombosis and provide no mortality benefit. In risk-stratified hemodynamically stable patients, an outpatient management strategy inclusive of therapeutic anticoagulation and careful clinical follow-up may be appropriate.

Mortality risk assessment and the role of thrombolysis in pulmonary embolism

Acute venous thromboembolism remains a frequent disease, with an incidence ranging between 23 and 69 cases per 100,000 population per year. Of these patients, approximately one-third present with clinical symptoms of acute pulmonary embolism (PE) and two-thirds with deep venous thrombosis (DVT). Recent registries and cohort studies suggest that approximately 10% of all patients with acute PE die during the first 1 to 3 months after diagnosis. Overall, 1% of all patients admitted to hospitals die of acute PE, and 10% of all hospital deaths are PE-related. These facts emphasize the need to better implement our knowledge on the pathophysiology of the disease, recognize the determinants of death or major adverse events in the early phase of acute PE, and most importantly, identify those patients who necessitate prompt medical, surgical, or interventional treatment to restore the patency of the pulmonary vasculature.

Endovascular therapy for acute pulmonary embolism

Acute pulmonary embolism (PE) is the third most common cause of death among hospitalized patients. Treatment escalation beyond anticoagulation therapy is necessary in patients with massive PE (defined by hemodynamic shock) as well as in many patients with submassive PE (defined by right ventricular strain). The best current evidence suggests that modern catheter-directed therapy to achieve rapid central clot debulking should be considered as an early or first-line treatment option for patients with acute massive PE; and emerging evidence suggests a catheter-directed thrombolytic infusion should be considered as adjunctive therapy for many patients with acute submassive PE. This article reviews the current approach to endovascular therapy for acute PE in the context of appropriate diagnosis, risk stratification, and management of acute massive and acute submassive PE.

[NT-proBNP for risk stratification of pulmonary embolism]

INTRODUCTION

Pulmonary embolism (PE) is an entity with high mortality and morbidity, in which risk stratification for adverse events is essential. N-terminal brain natriuretic peptide (NT-proBNP), a right ventricular dysfunction marker, may be useful in assessing the short-term prognosis of patients with PE.

AIMS

To characterize a sample of patients hospitalized with PE according to NT-proBNP level at hospital admission and to assess the impact of this biomarker on short-term evolution.

METHODS

We performed a retrospective analysis of consecutive patients admitted with PE over a period of 3.5 years. Based on the median NT-proBNP at hospital admission, patients were divided into two groups (Group 1: NT-proBNP<median and Group 2: NT-proBNP ≥ median). The two groups were compared in terms of demographic characteristics, personal history, clinical presentation, laboratory, electrocardiographic and echocardiographic data, drug therapy, in-hospital course (catecholamine support, invasive ventilation and in-hospital death and the combined endpoint of these events) and 30-day all-cause mortality. A receiver operating characteristic (ROC) curve was constructed to determine the discriminatory power and cut-off value of NT-proBNP for 30-day all-cause mortality.

RESULTS

Ninety-one patients, mean age 69±16.4 years (51.6% aged ≥75 years), 53.8% male, were analyzed. Of the total sample, 41.8% had no etiological or predisposing factors for PE and most (84.6%) were stratified as intermediate-risk PE. Median NT-proBNP was 2440 pg/ml. Patients in Group 2 were significantly older (74.8±13.2 vs. 62.8±17.2 years, p=0.003) and more had a history of heart failure (35.5% vs. 3.3%, p=0.002) and chronic kidney disease (32.3% vs. 6.7%, p=0.012). They had more tachypnea on initial clinical evaluation (74.2% vs. 44.8, p=0.02), less chest pain (16.1% vs. 46.7%, p=0.01) and higher creatininemia (1.7±0.9 vs. 1.1±0.5mg/dl, p=0.004). Group 2 also more frequently had right chamber dilatation (85.7% vs. 56.7%, p=0.015) and lower left ventricular ejection fraction (56.4±17.6% vs. 66.2±13.5%, p=0.036) on echocardiography. There were no significant differences in drug therapy between the two groups. Regarding the studied endpoints, Group 2 patients needed more catecholamine support (25.8% vs. 6.7%, p=0.044), had higher in-hospital mortality (16.1% vs. 0.0%, p=0.022) and more frequently had the combined endpoint (32.3% vs. 10.0%, p=0.034). All-cause mortality at 30 days was seen only in Group 2 patients (24.1% vs. 0.0%, p=0.034). By ROC curve analysis, NT-proBNP had excellent discriminatory power for this event, with an area under the curve of 0.848. The best NT-proBNP cut-off value was 4740 pg/ml.

CONCLUSION

Elevated NT-proBNP levels identified PE patients with worse short-term prognosis, and showed excellent power to predict 30-day all-cause mortality. The results of this study may have important clinical implications. The inclusion of NT-proBNP measurement in the initial evaluation of patients with PE can add valuable prognostic information.

Clinical review of pulmonary embolism: diagnosis, prognosis, and treatment

Pulmonary embolism (PE) is a common disease causing significant morbidity, mortality, and substantial socioeconomic costs. The correct diagnosis and management of PE, however, offers many challenges. As a result, ongoing research continues to develop and refine new and existing diagnostic and prognostic tools, as well as therapeutic interventions, leading to significant improvements in the care of PE over the past 2 decades. This article summarizes the current literature to aid the clinician in the correct integration and implementation of these advances in the treatment of PE.

Association of elevated NTproBNP with recurrent thromboembolic events after acute pulmonary embolism

INTRODUCTION

N-Terminal Pro-Brain Natriuretic Peptide (NTproBNP) is a predictor of adverse short-term clinical outcomes in patients with acute pulmonary embolism (APE), but its long-term prognostic value remains largely undefined. The aim of this study was to assess the value of plasma NTproBNP with regard to recurrent venous thromboembolism (VTE).

MATERIALS AND METHODS

NTproBNP levels were measured in 224 consecutive patients with the first episode of acute pulmonary embolism occurring from January 2005 through October 2010. Patients were categorized into two groups by NTproBNP reference range. Follow-ups were performed at 3, 6, and 12months and yearly thereafter. The primary end point was symptomatic, recurrent fatal or nonfatal VTE.

RESULTS

NTproBNP was elevated in 158 (70.5%) patients and not elevated in 66 (29.5%) patients. After a mean follow-up period of 31.0±19.4months, patients with elevated NTproBNP showed an increased risk of recurrent VTE (20 patients, 12.7%) compared to those without elevated NTproBNP (only 1 patient, 1.5%) (P=0.009). Of the 7 deaths related to pulmonary embolism, 6 occurred in patients with elevated NTproBNP compared to patients with normal NTproBNP (1 of 7 deaths). In a multivariate analysis stratified by oral anticoagulant treatment duration, elevated NTproBNP was an independent predictor of recurrent VTE (hazard ratio, 9.32; P=0.02).

CONCLUSIONS

Elevated NTproBNP is associated with recurrent VTE in acute pulmonary embolism patients.

Cardiac biomarkers in the critically ill

Cardiac biomarkers have well-established roles in acute coronary syndrome and congestive heart failure. In many instances, the detection of cardiac biomarkers may aid in the diagnosis and risk assessment of critically ill patients. Despite increasing interest in the use of cardiac biomarkers in noncardiac critical illness, no clear consensus exists on how and in which settings markers should be measured. This article briefly describes what constitutes an ideal biomarker and focuses on those that have been most well studied in critical illness, specifically troponin, the natriuretic peptides, and heart-type fatty acid-binding protein.