Combinations of prognostic tools for identification of high-risk normotensive patients with acute symptomatic pulmonary embolism

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.

Prognostic Value of Biomarkers in Acute Non-massive Pulmonary Embolism: A Systematic Review and Meta-analysis

BACKGROUND

Various biomarkers have been evaluated to risk stratify patients with acute pulmonary embolism (PE). We aimed to summarize the available evidence to compare the prognostic value of three most widely studied biomarkers in normotensive patients with acute PE.

METHOD

A systematic literature review of database, including Pubmed, EMBASE and Cochrane, was done. Studies were included if those were done on patients with acute PE and serum troponin or brain natriuretic peptide and N-terminal proBNP (BNP/NT-proBNP) or Heart-type fatty acid-binding protein (H-FABP) assay was done. The primary end point was short-term all-cause mortality. The secondary end points were PE-related mortality and serious adverse events.

RESULTS

All three biomarkers were significantly associated with increased risk for short-term all-cause mortality, PE-related mortality and serious adverse events. All-cause mortality: troponin [odds ratio (OR) 4.80; 95% CI 3.25-7.08, I(2) = 54%], BNP or NT-proBNP (OR 7.98; 95% CI 4.34-14.67, I(2) = 0%); PE-related mortality: troponin (OR 3.80; 95% CI 2.74-5.27, I(2) = 0%), BNP or NT-proBNP (OR 7.57; 95% CI 2.89-19.81, I (2) = 0%) and H-FABP (OR 25.97; 95% CI 6.63-101.66, I(2) = 40%). H-FABP has the lowest negative likelihood ratio (NLR) of 0.17 for mortality followed by high-sensitive cardiac troponin T (hs-cTnT) with NLR of 0.21.

CONCLUSION

None of the biomarker identifies a subgroup of patients who can be managed as an outpatient versus patients who may get benefit from thrombolytics with certainty; however, H-FABP and hs-cTnT showed some promising results and should be investigated further.

Short-term clinical outcome of normotensive patients with acute PE and high plasma lactate

BACKGROUND

Strategies for identifying normotensive patients with acute symptomatic PE at high risk of PE-related complications remain to be defined.

METHODS

This prospective cohort study aimed to determine the role of plasma lactate levels in the risk assessment of normotensive patients with acute PE. Outcomes assessed over the 7 days after the diagnosis of PE included PE-related mortality and haemodynamic collapse, defined as need for cardiopulmonary resuscitation, systolic blood pressure <90 mm Hg for at least 15 min, need for catecholamine administration, or need for mechanical ventilation.

RESULTS

Between December 2012 and January 2014, the study enrolled 496 normotensive outpatients with acute symptomatic PE. PE-related complications occurred in 20 (4.0%; 95% CI 2.5% to 6.2%) of the 496 patients. These patients had higher baseline lactate levels (median 2.66 mmol/L; IQR 1.56-5.96 mmol/L) than patients without complications (1.20 mmol/L; IQR 1.20-2.00 mmol/L) (p<0.001). Overall, 135 patients (27.2%) had plasma lactate ≥2 mmol/L. Fourteen (10.4%) of them had PE-related complications versus 6 of 361 patients with low lactate (negative predictive value 98.3%; p<0.001). Patients with elevated plasma lactate had an increased rate of PE-related complications (adjusted OR 5.3; 95% CI 1.9 to 14.4; p=0.001) compared with those with low lactate. The combination of elevated plasma lactate with markers of right ventricular dysfunction (by echocardiogram) and myocardial injury (by cardiac troponin) was a particularly useful prognostic indicator (positive predictive value 17.9%; 95% CI 6.1% to 36.9%).

CONCLUSIONS

Plasma lactate represents a powerful predictor of short-term PE-related complications and may provide guidance for decision-making in PE care.

Right ventricular dysfunction as an echocardiographic prognostic factor in hemodynamically stable patients with acute pulmonary embolism: a meta-analysis

BACKGROUND

We investigated whether right ventricular dysfunction (RVD) as assessed by echocardiogram can be used as a prognostic factor in hemodynamically stable patients with acute pulmonary embolism (PE). Short-term mortality has been investigated only in small studies and the results have been controversial.

METHODS

A PubMed search was conducted using two keywords, "pulmonary embolism" and "echocardiogram", for articles published between January 1st 1998 and December 31st 2011. Out of 991 articles, after careful review, we found 12 articles that investigated the implications of RVD as assessed by echocardiogram in predicting short-term mortality for hemodynamically stable patients with acute PE. We conducted a meta-analysis of these data to identify whether the presence of RVD increased short-term mortality.

RESULTS

Among 3283 hemodynamically stable patients with acute PE, 1223 patients (37.3%) had RVD, as assessed by echocardiogram, while 2060 patients (62.7%) had normal right ventricular function. Short-term mortality was reported in 167 (13.7%) out of 1223 patients with RVD and in 134 (6.5%) out of 2060 patients without RVD. Hemodynamically stable patients with acute PE who had RVD as assessed by echocardiogram had a 2.29-fold increase in short-term mortality (odds ratio 2.29, 95% confidence interval 1.61-3.26) compared with patients without RVD.

CONCLUSIONS

In hemodynamically stable patients with acute PE, RVD as assessed by echocardiogram increases short-term mortality by 2.29 times. Consideration should be given to obtaining echocardiogram to identify high-risk patients even if they are hemodynamically stable.

Derivation and validation of multimarker prognostication for normotensive patients with acute symptomatic pulmonary embolism

RATIONALE

Not all patients with acute pulmonary embolism (PE) have a high risk of an adverse short-term outcome.

OBJECTIVES

This prospective cohort study aimed to develop a multimarker prognostic model that accurately classifies normotensive patients with PE into low and high categories of risk of adverse medical outcomes.

METHODS

The study enrolled 848 outpatients from the PROTECT (PROgnosTic valuE of Computed Tomography) study (derivation cohort) and 529 patients from the Prognostic Factors for Pulmonary Embolism (PREP) study (validation cohort). Investigators assessed study participants for a 30-day complicated course, defined as death from any cause, hemodynamic collapse, and/or adjudicated recurrent PE.

MEASUREMENTS AND MAIN RESULTS

A complicated course occurred in 63 (7.4%) of the 848 normotensive patients with acute symptomatic PE in the derivation cohort and in 24 patients (4.5%) in the validation cohort. The final model included the simplified Pulmonary Embolism Severity Index, cardiac troponin I, brain natriuretic peptide, and lower limb ultrasound testing. The model performed similarly in the derivation (c-index of 0.75) and validation (c-index of 0.85) cohorts. The combination of the simplified Pulmonary Embolism Severity Index and brain natriuretic peptide testing showed a negative predictive value for a complicated course of 99.1 and 100% in the derivation and validation cohorts, respectively. The combination of all modalities had a positive predictive value for the prediction of a complicated course of 25.8% in the derivation cohort and 21.2% in the validation cohort.

CONCLUSIONS

For normotensive patients who have acute PE, we derived and validated a multimarker model that predicts all-cause mortality, hemodynamic collapse, and/or recurrent PE within the following 30 days.

Management dilemmas in acute pulmonary embolism

Background

Physicians treating acute pulmonary embolism (PE) are faced with difficult management decisions while specific guidance from recent guidelines may be absent.

Methods

Fourteen clinical dilemmas were identified by physicians and haematologists with specific interests in acute and chronic PE. Current evidence was reviewed and a practical approach suggested.

Results

Management dilemmas discussed include: sub-massive PE, PE following recent stroke or surgery, thrombolysis dosing and use in cardiac arrest, surgical or catheter-based therapy, failure to respond to initial thrombolysis, PE in pregnancy, right atrial thrombus, role of caval filter insertion, incidental and sub-segmental PE, differentiating acute from chronic PE, early discharge and novel oral anticoagulants.

Conclusion

The suggested approaches are based on a review of the available evidence and guidelines and on our clinical experience. Management in an individual patient requires clinical assessment of risks and benefits and also depends on local availability of therapeutic interventions.

Prognostic implications of computed tomographic right ventricular dilation in patients with acute pulmonary embolism

INTRODUCTION

Whether right ventricular (RV) dilation on computerized tomography (RVD-CT) is a useful predictor for clinical outcomes of acute pulmonary embolism (PE) remains debatable. Furthermore, data regarding the best combination of prognostic markers for predicting the adverse outcome of PE are limited.

MATERIALS AND METHODS

The authors retrospectively reviewed 657 consecutive patients hospitalized at a tertiary referral center with a diagnosis of PE based on multi-detector row CT scan.

RESULTS

Patients were allocated into an adverse outcome group (11% [n = 69]) or a low risk group (89% [n = 588]). Multivariate analysis showed that RVD-CT (RV/left ventricle [LV] diameter ratio ≥ 1), high pulmonary embolism severity index (PESI) score (class IV-V), high N-terminal-pro-B-type natriuretic peptide (NT-proBNP,≥ 1,136 pg/ml), and elevated troponin I (≥ 0.05 ng/ml) significantly predicted an adverse outcome (odds ratio [OR] 6.26, 95% confidence interval [CI] 2.74-14.31, p < 0.001; OR 4.71, 95% CI 2.00-11.07, p < 0.001; OR 2.71, 95% CI 1.15-6.39, p = 0.023; and OR 3.00, 95% CI 1.27-7.07, p = 0.012, respectively). The addition of RVD-CT to PESI, NT-proBNP, troponin I or their combinations enhanced the positive predictive values and positive likelihood ratios of an adverse outcome.

CONCLUSIONS

RVD-CT could be an independent prognostic factor of adverse outcomes in patients with acute PE, and provides additional prognostic value when combined with other prognostic factors.

Plasma levels of mitochondrial and nuclear DNA in patients with massive pulmonary embolism in the emergency department: a prospective cohort study

Introduction

Cell-free plasma mitochondrial DNA (mt-DNA) and nuclear DNA (n-DNA) are biomarkers with prognostic utility in conditions associated with a high rate of cell death. This exploratory study aimed to determine the plasma levels of both nucleic acids in patients with massive and submassive pulmonary embolism (PE) and to compare them with other biomarkers, such as heart-type fatty acid-binding protein (H-FABP) and troponin I (Tn-I)

Methods

This was a prospective observational study of 37 consecutive patients with massive PE, 37 patients with submassive PE, and 37 healthy subjects. Quantifications of plasma mt-DNA and n-DNA with real-time quantitative polymerase chain reaction (PCR), and plasma H-FABP and Tn-I by commercial assays, were done on blood samples drawn within 4 hours after presentation at the emergency department.

Results

Plasma mt-DNA and n-DNA concentrations were much higher in patients with massive PE (median, 2,970 GE/ml; interquartile range (IQR), 1,050 to 5,485; and 3,325 GE/ml, IQR: 1,080 to 5,790, respectively) than in patients with submassive PE (870 GE/ml and 1,245 GE/ml, respectively; P < 0.01) or controls (185 GE/ml and 520 GE/ml, respectively). Eighteen patients with massive PE died of a PE-related cause by day 15 of observation. Plasma mt-DNA and n-DNA values were 2.3-fold and 1.9-fold higher in the subgroup of nonsurviving patients than in survivors. H-FABP and Tn-I values were also higher in patients with massive PE who died (7.3 ng/ml and 0.023 ng/ml, respectively) than in those who survived (6.4 ng/ml, and 0.016 ng/ml, respectively). By receiver operating curve (ROC) analysis, the best cutoff values for predicting 15-day mortality were 3,380 GE/ml for mt-DNA, 6.8 ng/ml for H-FABP, 3,625 GE/ml for n-DNA, and 0.020 ng/ml for Tn-I, based on the calculated areas under the curve (AUCs) of 0.89 (95% confidence interval (CI), 0.78 to 0.99), 0.76 (95% CI, 0.69 to 093), 0.73 (95% CI, 0.58 to 0.91), and 0.59 (95% CI, 0.41 to 0.79), respectively. By stepwise logistic regression, a plasma mt-DNA concentration greater than 3,380 GE/ml (adjusted odds ratio (OR), 8.22; 95% CI, 1.72 to 39.18; P < 0.001) and a plasma value of H-FBAP >6.8 ng/ml (OR, 5.36; 95% CI, 1.06 to 27.08; P < 0.01) were the only independent predictors of mortality.

Conclusions

mt-DNA and H-FBAP might be promising markers for predicting 15-day mortality in massive PE, with mt-DNA having better prognostic accuracy.

Hestia criteria can safely select patients with pulmonary embolism for outpatient treatment irrespective of right ventricular function

BACKGROUND

There has been debate over how patients with pulmonary embolism (PE) can be safely selected for outpatient treatment.

OBJECTIVES

To compare the Hestia criteria with the European Society of Cardiology (ESC) criteria for selecting low-risk patients with PE for outpatient treatment.

METHODS

From 2008 to 2010, 496 patients with acute, symptomatic PE were screened and 275 treated at home and 221 treated in the hospital according to the Hestia Study protocol. The Hestia criteria were used to select patients for outpatient treatment. Right and left ventricular (RV and LV) diameters were measured on computed tomography images. RV dysfunction was defined as an RV/LV ratio > 1.0. Patients were classified according to the ESC criteria into low, intermediate and high-risk groups, based on blood pressure and RV dysfunction. During 3 months follow-up adverse events were scored.

RESULTS

Adverse events occurred in 22 patients (4.5%) treated in the hospital vs. none of the patients treated at home (P < 0.001). Sensitivity and negative predictive value for adverse outcome were 100% for the Hestia criteria and 96% and 99% for the ESC criteria, respectively. Of the patients treated at home according to the Hestia criteria, 35% were normotensive but had RV dysfunction and were classified as intermediate risk according to the ESC criteria. No adverse events happened in these patients treated at home.

CONCLUSIONS

Clinical criteria, such as the Hestia criteria, could be helpful in selecting patients, including those with RV dysfunction who have a low risk of adverse clinical outcome and could be candidates for outpatient treatment.

Predicting short term mortality after investigation for venous thromboembolism

INTRODUCTION

Deaths following diagnosis of venous thromboembolism (VTE) often result from another concurrent illness. The specificity of mortality markers predicting death from pulmonary embolism is unknown. The aim of this analysis was to compare blood predictors of death in patients with confirmed VTE to patients with negative investigations for VTE.

MATERIALS AND METHODS

Consecutive patients investigated for VTE were prospectively consented from a single hospital over 9months. VTE was diagnosed and excluded with a standard diagnostic algorithm. Blood was drawn for biomarker analysis and analyzed in batches for NT-proBNP, high sensitivity troponin T, C-reactive protein (CRP), fatty acid binding protein (FABP) and ischemia modified albumin (IMA). Participants were followed for 3months. The cohort was analyzed in two groups: those diagnosed with VTE and those who had thrombosis excluded. Regression analysis for 3-month mortality was performed for each group.

RESULTS

16/153 patients diagnosed with VTE died within three months (10.5%) as did 23/606 patients who had negative investigations for VTE (3.8%). Predictors for death following VTE included cancer, NT-proBNP, troponin T, FABP, and Hb<95g/L. NT-proBNP>500pg/ml in acute cancer associated VTE predicted death with C-statistic of 0.89 (0.80-0.99). Cancer, NT-proBNP and troponin T also predicted death in patients with negative investigations for VTE.

CONCLUSION

Several blood markers are not specific for death from PE and may be surrogate markers of global declining health.

Pulmonary embolism hotline 2012. Recent and expected trials

Management of acute pulmonary embolism (PE) has advanced considerably in the past year, and progress is expected to continue in 2013. To help determine the optimal management strategy for normotensive patients with intermediate-risk PE, the Pulmonary Embolism Thrombolysis (PEITHO) study completed enrolment of 1006 patients with evidence of right ventricular dysfunction (by echocardiography or computed tomography) plus a positive troponin test. Patients have been randomised to thrombolytic treatment with tenecteplase versus placebo, and the effects on clinical end points (death or haemodynamic collapse) assessed at 7 and 30 days. The results are expected in spring 2013; long-term follow-up is also being performed. The results of a randomised trial on ultrasound-enhanced low-dose catheter-delivered thrombolysis will also become available soon. While optimisation of treatment with vitamin K antagonists incorporating pharmacogenetic testing is still being pursued, new oral anticoagulants are entering the field of PE treatment and secondary prophylaxis. Following the successful use of rivaroxaban as single oral drug therapy in the EINSTEIN-PE trial, the approval of this drug has recently been extended to cover, apart from deep vein thrombosis, PE as well. The apixaban (AMPLIFY) and edoxaban (HOKUSAI) trials have finished recruitment of PE patients, and their results will become available shortly. In the meantime, the AMPLIFY-EXT trial showed that both the therapeutic (5 mg twice daily) and the prophylactic dose (2.5 mg twice daily) of apixaban are effective and safe for long-term secondary prophylaxis after PE. For the extended prophylaxis (after the reommended initial anticoagulation period) of the (few) patients who are unable to tolerate any form of anticoagulation, low-dose asprin may be a safe albeit moderately efficacious option, as indicated by two recent investigator-initiated trials with a total of 1224 patients.

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.

Prognostic significance of multidetector computed tomography in normotensive patients with pulmonary embolism: rationale, methodology and reproducibility for the PROTECT study

The PROTECT study is designed to assess the prognostic significance of multidetector computed tomography (MDCT) findings in normotensive outpatients with pulmonary embolism (PE). MDCT assesses right ventricular dysfunction (RVD) by measuring the ratio of the right-to-left ventricular short axis diameters. The study uses 30-day all-cause mortality as the primary outcome. The study determined inter- and intraobserver reproducibility of CT findings of RVD. According to the local radiologists' measurements, 44 % of patients (42/96) showed RVD (defined as a ratio of the RV to the LV short axis greater than 0.9). The intraclass correlation was good (0.773, CI 95 %, 0.678-0.842). For interobserver reproducibility, the weighted kappa measurement was 0.730. Intraobserver reproducibility was very good (0.932, 95 % CI, 0.880-0.962). The PROTECT study is designed to show the prognostic significance of MDCT for PE. Inter- and intraobserver agreement of interpretation of RVD were good.

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.

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.