Impact of the efficacy of thrombolytic therapy on the mortality of patients with acute submassive pulmonary embolism: a meta-analysis

Can GRACE Risk Score Predict Mortality and the Need for Thrombolytic Treatment in Acute Pulmonary Embolism?

Acute coronary syndrome and pulmonary embolism (PE) are clinical entities sharing similar presentation and risk factors. Risk scores and indexes help to identify disease severity in both diseases. In this study, we aimed to evaluate if the Global Registry of Acute Coronary Events (GRACE) risk score could predict 30-day mortality and the need for thrombolytic treatment in patients with acute PE. Patients hospitalized with a diagnosis of PE in our tertiary center between January 2018 and May 2022 were included in this retrospective study. Pulmonary Embolism Severity Index (PESI) and GRACE risk scores on admission were calculated using clinical, electrocardiographic, and laboratory parameters for each patient. A total of 197 patients were included. The 30-day mortality rate was 28.4% whereas 32.5% of the patients required thrombolytic treatment. GRACE and PESI scores were found independent risk factors associated with 30-day mortality and the need for thrombolytic treatment. A cut-off value of 160.5 for GRACE score was associated with 88.5% sensitivity and 89.4% specificity in prediction of 30-day mortality. In contrast, GRACE score had 61.0% sensitivity and 60.0% specificity in the prediction of the need for thrombolytic treatment when the cut-off value was 147. In conclusion, GRACE risk score has an effective discriminating power in determining the early mortality of patients with acute PE. The incidence of short-term PE-related mortality was significantly increased in patients with high GRACE risk scores. Concomitant use of GRACE and PESI risk scores may aid in defining patients with high-risk PE and help predict poor prognosis with high specificity and probability.

Mechanical thrombectomy is associated with shorter length of hospital stay and lower readmission rates compared with conservative therapy for acute submassive pulmonary embolism: a propensity-matched analysis

PURPOSE

To determine if mechanical thrombectomy (MT) for submassive pulmonary embolism (PE) positively impacts length of hospital stay (LOS), intensive care unit stay (ICU LOS), readmission rate, and in-hospital mortality compared with conservative therapy.

METHODS

This was a retrospective review of all patients with submassive PE who either underwent MT or conservative therapy (systemic anticoagulation and/or inferior vena cava filter) between November 2019 and October 2021. Pediatric patients (age <18) and those with low-risk and massive PEs were excluded from the study. Patient characteristics, comorbidities, vitals, laboratory values (cardiac biomarkers, hospital course, readmission rates, and in-hospital mortality) were recorded. A 2:1 propensity score match was performed on the conservative and MT cohorts based on age and the PE severity index (PESI) classification. Fischer's exact test, Pearson's χ2 test, and Student's t-tests were used to compare patient demographics, comorbidities, LOS, ICU LOS, readmission rates, and mortality rates, with statistical significance defined as P < 0.05. Additionally, a subgroup analysis based on PESI scores was assessed.

RESULTS

After matching, 123 patients were analyzed in the study, 41 in the MT cohort and 82 in the conservative therapy cohort. There was no significant difference in patient demographics, comorbidities, or PESI classification between the cohorts, except for increased incidence of obesity in the MT cohort (P = 0.013). Patients in the MT cohort had a significantly shorter LOS compared with the conservative therapy cohort (5.37 ± 3.93 vs. 7.76 ± 9.53 days, P = 0.028). However, ICU LOS was not significantly different between the cohorts (2.34 ± 2.25 vs. 3.33 ± 4.49, P = 0.059). There was no significant difference for in-hospital mortality (7.31% vs. 12.2%, P = 0.411). Of those that were discharged from the hospital, there was significantly lower incidence of 30-day readmission in the MT cohort (5.26% vs. 26.4%, P < 0.001). A subgroup analysis did not demonstrate that the PESI score had a significant impact on LOS, ICU LOS, readmission, or in-hospital mortality rates.

CONCLUSION

MT for submassive PE can reduce the total LOS and 30-day readmission rates compared with conservative therapy. However, in-hospital mortality and ICU LOS were not significantly different between the two groups.

Outcome of massive pulmonary embolism treated only with extracorporeal membrane oxygenation and anticoagulation without thrombolytic therapy or surgical embolectomy

INTRODUCTION

Although thrombolytic therapy is the standard treatment for massive pulmonary thromboembolism (PTE), it is often ineffective in patients with circulatory collapse. Surgical embolectomy is another treatment option, but whether it is absolutely necessary is controversial. We sought to evaluate the outcomes of patients with massive PTE treated with intensive critical care including extracorporeal membrane oxygenation (ECMO) without thrombolytic therapy or surgical embolectomy.

METHODS

We analyzed 39 patients who were treated for massive PTE from January 2011 to June 2019. Massive PTE was treated with anticoagulation and hemodynamic support at an intensive care unit. ECMO was applied in patients with circulatory collapse. The computed tomography (CT) obstruction index and the ratio of the right ventricle to left ventricle short-axis diameters (RV/LV) were measured using serial CT angiography to confirm changes in pulmonary emboli and RV strain.

RESULTS

Twenty-one patients were in cardiogenic shock, and 15 of them needed cardiopulmonary resuscitation (CPR). Fifteen patients were treated with ECMO and nine of them were weaned successfully. The overall in-hospital mortality was 23% (9/39). On the follow-up CT scan after 6 months, residual PTE was observed in 10 patients and their median CT obstruction index was 6.25 % (range 2.5-35). The initial mean RV/LV ratio was 1.8 ± 0.47 and the value measured at follow-up CT decreased to less than 1 (0.9 ± 0.1).

CONCLUSIONS

Intensive critical care with heparin alone and timely ECMO support without thrombolytic therapy could be an effective treatment option in patients with acute massive PTE.

Improved long-term outcomes with catheter-directed therapies over medical management in patients with submassive pulmonary embolism-a retrospective matched cohort study

BACKGROUND

The benefit of catheter-directed therapy (CDT) for submassive pulmonary embolism (sPE) has been the subject of debate. We sought to determine the short- and long-term mortality and outcomes of CDT compared with anticoagulation for patients with sPE.

METHODS

We performed a single healthcare network, multihospital, retrospective cohort study of hospitalizations for sPE from 2012 to 2019. sPE was defined as the presence of right heart strain or elevated biomarkers (troponin I or B-type natriuretic peptide). Patients with massive PE and those who had undergone systemic thrombolysis were excluded. The sPE groups included therapeutic anticoagulation alone or anticoagulation plus CDT (ie, thrombolysis or suction thrombectomy). The primary outcome was mortality at 1, 3, and 5 years. The other measured outcomes included PE-related death, short term mortality (30 days and 3 and 6 months), 30-day treatment-related complications (eg, bleeding, transfusion, stroke), chronic thromboembolic pulmonary hypertension, and 6-minute walk test at 1 year. After 1:1 nearest-neighbor propensity score matching, Kaplan-Meier survival plots were generated, and the treatment groups were compared using log-rank testing. We used Cox multivariate analysis to evaluate the outcomes after clustering at the hospital level, generating matched hazard ratios (mHRs) with associated 95% confidence intervals (CIs).

RESULTS

Of 6746 sPE hospitalizations, the patients who had received CDT were younger (age, 58.9 ± 15.5 years vs 61.5 ± 17.4 years; P = .004), were more frequently White (92.5% vs 85.7%; P < .001), and had presented with a higher mean heart rate (104.6 bpm vs 94.9 bpm; P < .001), lower median systolic blood pressure (129 mm Hg vs 135 mm Hg; P < .001), and a greater incidence of right heart strain (79.2% vs 20.3%; P < .001). A total of 470 patients were matched, with 235 in the CDT group and 235 in the anticoagulation-only group. CDT was associated with a lower risk of mortality compared with anticoagulation at 1 year (7.6% vs 9.8%; mHR, 0.77; 95% CI, 0.65-0.92; P = .004), 3 years (11.1% vs 16.6%; mHR, 0.64; 95% CI, 0.55-0.73; P < .001), and 5 years (14.5% vs 19.1%; mHR, 0.71; 95% CI, 0.66-0.77; P < .001). Anticoagulation alone resulted in a greater incidence of PE-related deaths at 1, 3, and 5 years. The mortality at 30 days and 3 months was similar; however, CDT had resulted in better survival at 6 months (mHR, 0.81; 95% CI, 0.68-0.97; P = .02). No differences were found between the two groups in the incidence of bleeding complications at 30 days, development of chronic thromboembolic pulmonary hypertension, or the mean walking distance at 1 year.

CONCLUSIONS

CDT plus anticoagulation for sPE was associated with improved long-term survival compared with anticoagulation alone, with a lower incidence of PE-related death and a low complication rate. CDT should be considered for select patients with sPE given its survival benefit.

Comparison of Efficacy and Safety between Thrombolysis Plus Anticoagulation vs. Anticoagulation Alone for the Treatment of Acute Submassive Pulmonary Embolism: A Systematic Review and Meta-analysis

OBJECTIVE

The objective of this study is to compare the efficacy and safety of thrombolysis plus anticoagulant therapy vs. anticoagulant therapy alone in acute submassive pulmonary embolism (PE).

MATERIALS AND METHODS

The PubMed, Embase, and Cochrane Library databases were searched for randomized clinical trials comparing thrombolytic therapy and anticoagulation vs. anticoagulation alone in acute submassive PE patients from 1 Jan 1980 to 20 Jan 2021, with no drug or dose restrictions. Data on upgraded treatment of clinical deterioration, all-cause mortality, PE recurrence and bleeding events were extracted and analyzed using Revman 5.3 software.

RESULTS

A total of 10 randomized controlled trials involving 1871 patients were included in the study after screening. In terms of efficacy, thrombolysis combined with anticoagulant therapy reduced the need for upgrading treatment (3.6 vs. 10.9%, risk ratio (RR) 0.36, 95% confidence interval (CI) 0.24- 0.54, p<0.00001) and PE recurrence (0.8 vs. 2.9%, RR 0.33, 95% CI 0.16-0.69, p=0.003) in patients with acute submassive PE. Compared with anticoagulant therapy alone, the concomitant use of thrombolysis was associated with lower all-cause mortality (1.3 vs. 3.0%, RR 0.47, 95% CI 0.26-0.87, p=0.02), but it increased minor bleeding rate (31.4 vs. 8.4%, RR 3.71, 95% CI 2.82-4.88, p<0.0001) and major bleeding rate (8.8 vs. 2.6%, RR 3.35, 95%CI 2.03-5.54, p<0.0001).

CONCLUSION

The use of thrombolysis plus anticoagulant therapy in acute submassive PE was negatively associated with patients requiring escalation of treatment, PE recurrence, and all-cause mortality, but it was positively associated with bleeding.

Dilemmas in the Choice of Adequate Therapeutic Treatment in Patients with Acute Pulmonary Embolism—From Modern Recommendations to Clinical Application

Pulmonary thromboembolism is a very common cardiovascular disease, with a high mortality rate. Despite the clear guidelines, this disease still represents a great challenge both in diagnosis and treatment. The heterogeneous clinical picture, often without pathognomonic signs and symptoms, represents a huge differential diagnostic problem even for experienced doctors. The decisions surrounding this therapeutic regimen also represent a major dilemma in the group of patients who are hemodynamically stable at initial presentation and have signs of right ventricular (RV) dysfunction proven by echocardiography and positive biomarker values (pulmonary embolism of intermediate–high risk). Studies have shown conflicting results about the benefit of using fibrinolytic therapy in this group of patients until hemodynamic decompensation, due to the risk of major bleeding. The latest recommendations give preference to new oral anticoagulants (NOACs) compared to vitamin K antagonists (VKA), except for certain categories of patients (patients with antiphospholipid syndrome, mechanical valves, pregnancy). When using oral anticoagulant therapy, special attention should be paid to drug–drug interactions, which can lead to many complications, even to the death of the patient. Special population groups such as pregnant women, obese patients, patients with antiphospholipid syndrome and the incidence of cancer represent a great therapeutic challenge in the application of anticoagulant therapy. In these patients, not only must the effectiveness of the drugs be taken into account, but great attention must be paid to their safety and possible side effects, which is why a multidisciplinary approach is emphasized in order to provide the best therapeutic option.

Intermediate-Risk Pulmonary Embolism: A Review of Contemporary Diagnosis, Risk Stratification and Management

Pulmonary embolism (PE) can have a wide range of hemodynamic effects, from asymptomatic to a life-threatening medical emergency. Pulmonary embolism (PE) is associated with high mortality and requires careful risk stratification for individualized management. PE is divided into three risk categories: low risk, intermediate-risk, and high risk. In terms of initial therapeutic choice and long-term management, intermediate-risk (or submassive) PE remains the most challenging subtype. The definitions, classifications, risk stratification, and management options of intermediate-risk PE are discussed in this review.

Meta-Analysis Comparing Catheter-Directed Thrombolysis Versus Systemic Anticoagulation Alone for Submassive Pulmonary Embolism

The optimal therapy for submassive pulmonary embolism (sPE), defined by right ventricular dysfunction without hemodynamic instability, is uncertain. We conducted a systematic review and meta-analysis to compare the outcomes of catheter-directed thrombolysis (CDT) versus systemic anticoagulation (SA) alone in patients with sPE. We searched PubMed, EMBASE, Cochrane, ClinicalTrials.gov, and Google Scholar (from inception through May 2022) for studies comparing outcomes of CDT versus SA in sPE. Studies were identified, and data were extracted by 2 independent reviewers. We used a random-effects model to calculate risk ratios (RRs) with 95% confidence intervals (CIs). Outcomes included in-hospital, 30-day, 90-day, and 1-year mortality, major and minor bleeding, and need for blood transfusion. A total of 12 studies (1 randomized, 11 observational) with 9,789 patients were included. Compared with SA, CDT was associated with significantly lower in-hospital mortality (RR 0.41, 95% CI 0.30 to 0.56, p <0.00001), 30-day mortality (RR 0.37, 95% CI 0.18 to 0.73, p = 0.004), 90-day mortality (RR 0.36, 95% CI 0.17 to 0.72, p = 0.004), and a tendency toward lower 1-year mortality (RR 0.56, 95% CI 0.29 to 1.05, p = 0.07). The risks of major bleeding (RR 1.31, 95% CI 0.57 to 3.01, p = 0.53), minor bleeding (RR 1.67, 95% CI 0.77 to 3.63, p = 0.20), and the rates of blood transfusion (RR 0.34, 95% CI 0.10 to 1.15, p = 0.08) were similar between the 2 strategies. In conclusion, in patients with sPE, CDT is associated with significantly lower in-hospital, 30-day, and 90-day mortality and a tendency toward lower 1-year mortality with similar bleeding rates compared with SA. This study expands the evidence supporting CDT as first-line therapy for sPE, and randomized controlled trials are indicated to confirm our findings.

Injection of Recombinant Tissue Plasminogen Activator into Extracorporeal Membrane Oxygenators Postpones Oxygenator Exchange in COVID-19

Coronavirus disease 2019 (COVID-19) has drastically increased the number of patients requiring extracorporeal life support. We investigate the efficacy and safety of low-dose recombinant tissue-type plasminogen activator (rtPA) injection into exhausted oxygenators to delay exchange in critically ill COVID-19 patients on veno-venous extracorporeal membrane oxygenation (V-V ECMO). Small doses of rtPA were injected directly into the draining section of a V-V ECMO circuit. We compared transmembrane pressure gradient, pump head efficiency, membrane arterial partial oxygen pressure, and membrane arterial partial carbon dioxide pressure before and after the procedure. Bleeding was compared with a matched control group of 20 COVID-19 patients on V-V ECMO receiving standard anticoagulation. Four patients received 16 oxygenator instillations with rtPA at 5, 10, or 20 mg per dose. Administration of rtPA significantly reduced transmembrane pressure gradient (Δpm = 54.8 ± 18.1 mmHg before vs. 38.3 ± 13.3 mmHg after, p < 0.001) in a dose-dependent manner (Pearson's R -0.63, p = 0.023), allowing to delay oxygenator exchange, thus reducing the overall number of consumed oxygenators. rtPA increased blood flow efficiency η (1.20 ± 0.28 ml/revolution before vs. 1.24 ± 0.27 ml/r, p = 0.002). Lysis did not affect membrane blood gases or systemic coagulation. Minor bleeding occurred in 2 of 4 patients (50%) receiving oxygenator lysis as well as 19 of 20 control patients (95%). Lysis of ECMO oxygenators effectively delays oxygenator exchange, if exchange is indicated by an increase in transmembrane pressure gradient. Application of lysis did not result in higher bleeding incidences compared with anticoagulated patients on V-V ECMO for COVID-19.

Modulation of soluble guanylate cyclase ameliorates pulmonary hypertension in a rat model of chronic thromboembolic pulmonary hypertension by stimulating angiogenesis

Acute pulmonary embolism (PE) does not always resolve after treatment and can progress to chronic thromboembolic disease (CTED) or the more severe chronic thromboembolic pulmonary hypertension (CTEPH). The mechanisms surrounding the likelihood of PE resolution or progress to CTED/CTEPH remain largely unknown. We have developed a rat model of CTEPH that closely resembles the human disease in terms of hemodynamics and cardiac manifestations. Embolization of rats with polystyrene microspheres followed by suppression of angiogenesis with the inhibitor of vascular endothelial growth factor receptor 2 (VEGF-R2) SU5416 results in transient, acute pulmonary hypertension that progresses into chronic PE with PH with sustained right ventricular systolic pressures exceeding 70 mmHg (chronic pulmonary embolism [CPE] model). This model is similar to the widely utilized hypoxia/SU5416 model with the exception that the "first hit" is PE. Rats with CPE have impaired right heart function characterized by reduced VO2 Max, reduced cardiac output, and increased Fulton index. None of these metrics are adversely affected by PE alone. Contrast-mediated CT imaging of lungs from rats with PE minus SU5416 show large increases in pulmonary vascular volume, presumably due to an angiogenic response to acute PE/PH. Co-treatment with SU5416 suppresses angiogenesis and produces the CTEPH-like phenotype. We report here that treatment of CPE rats with agonists for soluble guanylate cyclase, a source of cGMP which is in turn a signal for angiogenesis, markedly increases angiogenesis in lungs, and ameliorates the cardiac deficiencies in the CPE model. These results have implications for future development of therapies for human CTEPH.

Catheter-directed Thrombolysis versus Systemic Anticoagulation for Submassive Pulmonary Embolism: A Meta-Analysis

BACKGROUND

The optimal therapy for submassive pulmonary embolism remains in question. The following meta-analysis compiles the current evidence comparing Catheter-Directed Thrombolysis (CDT) versus Systemic Anticoagulation (SA).

METHODS

An electronic search through PubMed and Google scholar revealed studies comparing CDT versus SA in terms of mortality and major bleeding events. Thirty-day, 90-day, and one-year mortality results were analyzed.

RESULTS

Six studies were included in the meta-analysis. Thirty-day and one-year mortality were less with CDT compared to SA (OR 0.27 [CI 0.11-0.67]; and OR 0.50 [CI 0.28-0.89]). Ninety-day mortality was similar between the two methods (OR 0.57 [CI 0.17-1.92]). Compilation of all studies reporting at least greater than 30-day mortality revealed less mortality with CDT (OR 0.51 [0.30-0.86]). Major bleeding was similar between the two treatments (OR 1.63 [CI 0.63-4.20]).

CONCLUSION

CDT has less 30-day and 1-year mortality with equivalent rates of major bleeding compared to SA for treatment of submassive pulmonary embolism.

Prevalence of pulmonary embolism in patients with acute exacerbations of COPD: A systematic review and meta-analysis

STUDY OBJECTIVE

Identification of pulmonary embolism (PE) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) carries significant therapeutic implications. We aimed to investigate the prevalence of PE in patients with AECOPD.

METHODS

We searched MEDLINE, the Cochrane Central Register of Controlled Trials, and Embase. We registered the protocol at the PROSPERO (CRD42021230481). Two authors independently evaluated whether titles and abstracts met the eligibility criteria, which were as follows: (1), prospective study or cross-sectional study in case the protocol for workup of PE was specified in advance, (2) patients with AECOPD aged ≥ 18 years, and (3) investigated the prevalence of PE or venous thromboembolism (VTE). Two authors independently extracted the selected patient and study characteristics and outcomes. We presented the results of all analyses with the use of random-effects models. The primary outcome was the prevalence of PE.

RESULTS

We included 16 studies (N = 4093 patients) in this meta-analysis. The prevalence of PE in patients with AECOPD was 12% [95% confidence interval (CI), 9 to 16%]. Substantial heterogeneity was observed (I² = 94.8%). The pooled mortality was higher in patients with PE than those without (odds ratio 5.30, 95%CI: 2.48-11.30, p-value < 0.001).

CONCLUSION

In this meta-analysis, the prevalence of PE in patients with AECOPD was 12% and the mortality of patients with PE was higher than those without. This suggests an acute necessity to develop validated diagnostic strategies for identifying PE in patients with AECOPD.

Low-dose thrombolysis for submassive pulmonary embolism

The role of thrombolysis in submassive pulmonary embolism (PE) is controversial due to the high risk of hemorrhage. This study aimed to evaluate the role of half-dose tissue-type plasminogen activator (rt-PA) in preventing death/hemodynamic decompensation in submassive (intermediate-risk) PE without increasing the risk of bleeding. In a prospective, non-randomized, open-label, single-center trial, we compared 50 mg rt-PA plus low molecular weight heparin (LMWH) with LMWH in submassive (intermediate-risk) PE. Eligible cases had confirmed pulmonary hypertension on echocardiography, and/or right ventricular cavity expansion and/or interventricular septal deviation on echocardiography, and/or right to left ventricular ratio equal to or greater than 0.9 mm on CT angiography. The primary outcome was death or hemodynamic decompensation within 7 and 30 days after treatment was given. The primary safety outcome was major extracranial bleeding or hemorrhagic stroke within 7 days. Seventy-six patients were included in the study. Total death/hemodynamic decompensation in the first 7 and 30 days was significantly less in the half-dose rt-PA group than in the LMWH group (p=0.028 and p=0.009, respectively). No significant differences were found between the two groups in terms of recurrent embolism and pulmonary hypertension at 6-month follow-up (p=1.000 and p=0.778). There was no intracranial hemorrhage in any of the patients. There were no statistically significant differences between the two groups in terms of major or minor bleeding complications. This trial showed half-dose rt-PA treatment in submassive (intermediate-risk) PE prevented death/hemodynamic decompensation in the first 7-day and 30-day period compared with LMWH treatment without increasing the risk of bleeding.

Submassive Pulmonary Embolism: Current Perspectives and Future Directions

Submassive pulmonary embolism (PE) lies on a spectrum of disease severity between standard and high-risk disease. By definition, patients with submassive PE have a worse outcome than the majority of those with standard-risk PE, who are hemodynamically stable and lack imaging or laboratory features of cardiac dysfunction. Systemic thrombolytic therapy has been proven to reduce mortality in patients with high-risk disease; however, its use in submassive PE has not demonstrated a clear benefit, with haemodynamic improvements being offset by excess bleeding. Furthermore, meta-analyses have been confusing, with conflicting results on overall survival and net gain. As such, significant interest remains in optimising thrombolysis, with recent efforts in catheter-based delivery as well as upcoming studies on reduced systemic dosing. Recently, long-term cardiorespiratory limitations following submassive PE have been described, termed post-PE syndrome. Studies on the ability of thrombolytic therapy to prevent this condition also present conflicting evidence. In this review, we aim to clarify the current evidence with respect to submassive PE management, and also to highlight shortcomings in current definitions and prognostic factors. Additionally, we discuss novel therapies currently in preclinical and early clinical trials that may improve outcomes in patients with submassive PE.

Thrombolytic therapy for pulmonary embolism

BACKGROUND

Thrombolytic therapy is usually reserved for people with clinically serious or massive pulmonary embolism (PE). Evidence suggests that thrombolytic agents may dissolve blood clots more rapidly than heparin and may reduce the death rate associated with PE. However, there are still concerns about the possible risk of adverse effects of thrombolytic therapy, such as major or minor haemorrhage. This is the fourth update of the Cochrane review first published in 2006.

OBJECTIVES

To assess the effects of thrombolytic therapy for acute pulmonary embolism.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 17 August 2020. We undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared thrombolytic therapy followed by heparin versus heparin alone, heparin plus placebo, or surgical intervention for people with acute PE (massive/submassive). We did not include trials comparing two different thrombolytic agents or different doses of the same thrombolytic drug.

DATA COLLECTION AND ANALYSIS

Two review authors (ZZ, QH) assessed the eligibility and risk of bias of trials and extracted data. We calculated effect estimates using the odds ratio (OR) with a 95% confidence interval (CI) or the mean difference (MD) with a 95% CI. The primary outcomes of interest were death, recurrence of PE and haemorrhagic events. We assessed the certainty of the evidence using GRADE criteria.

MAIN RESULTS

We identified three new studies for inclusion in this update. We included 21 trials in the review, with a total of 2401 participants. No studies compared thrombolytics versus surgical intervention. We were not able to include one study in the meta-analysis because it provided no extractable data. Most studies carried a high or unclear risk of bias related to randomisation and blinding. Meta-analysis showed that, compared to control (heparin alone or heparin plus placebo), thrombolytics plus heparin probably reduce both the odds of death (OR 0.58, 95% CI 0.38 to 0.88; 19 studies, 2319 participants; low-certainty evidence), and recurrence of PE (OR 0.54, 95% CI 0.32 to 0.91; 12 studies, 2050 participants; low-certainty evidence). Effects on mortality weakened when six studies at high risk of bias were excluded from analysis (OR 0.71, 95% CI 0.45 to 1.13; 13 studies, 2046 participants) and in the analysis of submassive PE participants (OR 0.61, 95% CI 0.37 to 1.02; 1993 participants). Effects on recurrence of PE also weakened after removing one study at high risk of bias for sensitivity analysis (OR 0.60, 95% CI 0.35 to 1.04; 11 studies, 1949 participants). We downgraded the certainty of evidence to low because of 'Risk of bias' concerns. Major haemorrhagic events were probably more common in the thrombolytics group than in the control group (OR 2.84, 95% CI 1.92 to 4.20; 15 studies, 2101 participants; moderate-certainty evidence), as were minor haemorrhagic events (OR 2.97, 95% CI 1.66 to 5.30; 13 studies,1757 participants; low-certainty evidence). We downgraded the certainty of the evidence to moderate or low because of 'Risk of bias' concerns and inconsistency. Haemorrhagic stroke may occur more often in the thrombolytics group than in the control group (OR 7.59, 95% CI 1.38 to 41.72; 2 studies, 1091 participants). Limited data indicated that thrombolytics may benefit haemodynamic outcomes, perfusion lung scanning, pulmonary angiogram assessment, echocardiograms, pulmonary hypertension, coagulation parameters, composite clinical outcomes, need for escalation and survival time to a greater extent than heparin alone. However, the heterogeneity of the studies and the small number of participants involved warrant caution when interpreting results. The length of hospital stay was shorter in the thrombolytics group than in the control group (mean difference (MD) -1.40 days, 95% CI -2.69 to -0.11; 5 studies, 368 participants). Haemodynamic decompensation may occur less in the thrombolytics group than in the control group (OR 0.36, 95% CI 0.20 to 0.66; 3 studies, 1157 participants). Quality of life was similar between the two treatment groups. None of the included studies provided data on post-thrombotic syndrome or on cost comparison.

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that thrombolytics may reduce death following acute pulmonary embolism compared with heparin (the effectiveness was mainly driven by one trial with massive PE). Thrombolytic therapy may be helpful in reducing the recurrence of pulmonary emboli but may cause more major and minor haemorrhagic events, including haemorrhagic stroke. More studies of high methodological quality are needed to assess safety and cost effectiveness of thrombolytic therapy for people with pulmonary embolism.

Aggressive Therapy for Acute Pulmonary Embolism: Systemic Thrombolysis and Catheter-Directed Approaches

Venous thromboembolism (VTE) is the third most common cause of cardiovascular disease after myocardial infarction and stroke. Population-based studies estimate that up to 94,000 new cases of pulmonary embolism (PE) occur in the United States annually with an increasing incidence with age. Mortality from PE is the greatest in the first 24 hours, with a decreased survival extending out 3 months. Thus, acute PE is a potentially fatal illness if not recognized and treated in a timely manner. Contemporary management includes systemic anticoagulation, thrombolysis, catheter-based procedures, and surgical embolectomy. This article reviews current clinical evidence and societal guidelines for the use of systemic and catheter-directed thrombolysis for treatment of acute PE.

Current Endovascular Treatment Options in Acute Pulmonary Embolism

Acute pulmonary embolism (PE) is a significant cause of mortality and morbidity across the globe. Over the last few decades, there have been major therapeutic advances in acute PE management, including catheter-based therapy. However, the effectiveness of catheter-based therapy in acute PE is not supported by Level I evidence, making the use of this promising treatment rather controversial and ambiguous. In this paper, we discuss the risk stratification of acute PE and review the medical and endovascular treatment options. We also summarize and review the data supporting the use of endovascular treatment options in acute PE and describe the potential role of the PE response team.

The net benefit of thrombolysis in the management of intermediate risk pulmonary embolism: Systematic review and meta‐analysis

Background

Benefit of thrombolytic therapy in patients with massive pulmonary embolism (PE) is evident. However, evidence supporting benefit in clinical outcomes of this approach in intermediate risk PE is lacking.

Objective

To determine the impact of thrombolysis on overall survival in intermediate risk PE patients.

Methods

We searched in MEDLINE (OVID), EMBASE, LILACS, and the Cochrane Central Register of Controlled Trials (CENTRAL) from present day. We also searched in other databases and unpublished literature. We included clinical trials without language restrictions. The risk of bias was evaluated with the Cochrane Collaboration's tool. The primary outcome was overall survival. Secondary outcomes were adverse events, including major bleeding, and all‐cause mortality. The measure of the effect was the risk ratio with a 95% confidence interval (CI).

Results

We included 11 studies in the qualitative and quantitative analysis, with a total of 1855 patients. Risk of bias was variable among the study items. There were no results reported about overall survival in any of the studies. The risk ratio (RR) for all‐cause mortality was 0.68 95% CI (0.40 to 1.16). The RR of overall bleeding, major bleeding and stroke were 2.72 95% CI (1.58 to 4.69), 2.17 95% CI (1.03 to 4.55), and 2.22 95% CI (0.17 to 28.73), respectively. Additionally, the RR for recurrent PE was 0.56 95% CI (0.23 to 1.37).

Conclusions

In patients with intermediate risk PE, the risk of bleeding is higher when thrombolysis is used. There was no significant difference between thrombolysis and anticoagulation in recurrence of PE, stroke, and all‐cause mortality.

Fibrinolytics for the treatment of pulmonary embolism

The use of fibrinolytic agents in acute pulmonary embolism (PE), first described over 50 years ago, hastens the resolution of RV stain, leading to earlier hemodynamic improvement. However, this benefit comes at the increased risk of bleeding. The strongest indication for fibrinolysis is in high-risk PE, or that characterized by sustained hypotension, while its use in patients with intermediate-risk PE remains controversial. Fibrinolysis is generally not recommended for routine use in intermediate-risk PE, although most guidelines advise that it may be considered in patients with signs of acute decompensation and an overall low bleeding risk. The efficacy of fibrinolysis often varies significantly between patients, which may be at least partially explained by several factors found to promote resistance to fibrinolysis. Ultimately, treatment decisions should carefully weigh the risks and benefits of the individual clinical scenario at hand, including the overall severity, the patient's bleeding risk, and the presence of factors known to promote resistance to fibrinolysis. This review aims to further explore the use of fibrinolytic agents in the treatment of PE including specific indications, outcomes, and special considerations.

American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), occurs in ∼1 to 2 individuals per 1000 each year, corresponding to ∼300 000 to 600 000 events in the United States annually.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support patients, clinicians, and others in decisions about treatment of VTE.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and adult patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 28 recommendations for the initial management of VTE, primary treatment, secondary prevention, and treatment of recurrent VTE events.

CONCLUSIONS

Strong recommendations include the use of thrombolytic therapy for patients with PE and hemodynamic compromise, use of an international normalized ratio (INR) range of 2.0 to 3.0 over a lower INR range for patients with VTE who use a vitamin K antagonist (VKA) for secondary prevention, and use of indefinite anticoagulation for patients with recurrent unprovoked VTE. Conditional recommendations include the preference for home treatment over hospital-based treatment for uncomplicated DVT and PE at low risk for complications and a preference for direct oral anticoagulants over VKA for primary treatment of VTE.

Thrombolysis in Pulmonary Embolism: An Evidence-Based Approach to Treating Life-Threatening Pulmonary Emboli

Acute pulmonary embolism (PE) is associated with high in-hospital morbidity and mortality, both via cardiorespiratory decompensation and the bleeding complications of treatment. Thrombolytic therapy can be life-saving in those with high-risk PE, but requires careful patient selection. Patients with PE and systemic arterial hypotension ("massive PE") should receive thrombolytic therapy unless severe contraindications are present. Patients with PE and right ventricular dysfunction/injury, but without hypotension ("submassive PE"), should be considered for thrombolysis on a case-by-case basis, considering bleeding risk, cardiac biomarkers, echocardiography, and most importantly, clinical status.

Assessment of the Bova score for risk stratification of acute normotensive pulmonary embolism: A systematic review and meta-analysis

BACKGROUND

Identification of normotensive pulmonary embolism (PE) at high risk of early adverse outcome is crucial for guiding treatment. Studies showed the Bova score had promising performance in stratifying normotensive PE.

METHODS

We conducted a systematic review and meta-analysis to evaluate the prognostic performance of the Bova score for normotensive PE.

RESULTS

Nine studies involving 8342 acute normotensive PE patients were enrolled. Overall, 71.4%, 20.2% and 8.4% patients were stratified as risk class I, II and III. Pooled incidence of short-term PE related composite adverse outcome of each group were 3.8%, 10.8% and 19.9%, respectively, exhibiting a significant rising trend. Increasing trends of 30-day and in-hospital composite adverse outcome rates, as well as PE related mortality, were also observed with upper risk classes. Compared with risk class I and II, high risk group (class III) was significantly associated with short-term PE related composite adverse outcome (OR: 5.45, 95% CI, 3.70-8.02) and PE related death (OR: 5.09, 95% CI, 3.54-7.30). Pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of the score for predicting short-term composite adverse outcome were 0.25 (95% CI, 0.22-0.29), 0.93 (95% CI, 0.92-0.93), 4.05 (95% CI, 2.90-5.67) and 0.81 (95% CI, 0.74-0.88), respectively. The weighted area under the summarized receiver characteristics operation curve for predicting composite adverse outcome was 0.73 ± 0.09.

CONCLUSION

The Bova score could effectively discriminate normotensive PE with different short-term prognosis and has good performance in identifying patients at higher risk of short-term adverse events.

Systematic Review: The Role of Thrombolysis in Intermediate-Risk Pulmonary Embolism

BACKGROUND

This systemic review provides practicing emergency physicians updated information about the role of thrombolysis in the treatment of intermediate-risk pulmonary embolism.

METHODS

A PubMed literature search from January 1, 2005 to December 31, 2018 was conducted and limited to human clinical trials written in English with relevant keywords. High-quality studies were identified and then underwent a structured review. Recommendations are made based on the literature review.

RESULTS

Sixty-three articles met criteria for rigorous review, of which 13 were appropriate for citation in this review. Of these 13, there were 6 prospective studies and 7 retrospective studies.

CONCLUSIONS

Thrombolysis, either catheter-directed or systemic, is a treatment option in the management of patients with intermediate-risk pulmonary embolism and a high likelihood of clinical deterioration. Each method of thrombolysis carries risks and benefits. Based on the available evidence, transfer to a facility for the purpose of catheter-directed thrombolysis is not recommended.

Acute pulmonary embolism: a concise review of diagnosis and management

An acute pulmonary embolism (aPE) is characterised by occlusion of one or more pulmonary arteries. Physiological disturbance may be minimal, but often cardiac output decreases as the right ventricle attempts to overcome increased afterload. Additionally, ventilation-perfusion mismatches can develop in affected vascular beds, reducing systemic oxygenation. Incidence is reported at 50-75 per 100 000 in Australia and New Zealand, with 30-day mortality rates ranging from 0.5% to over 20%. Incidence is likely to increase with the ageing population, increased survival of patients with comorbidities that are considered risk factors and improving sensitivity of imaging techniques. Use of clinical prediction scores, such as the Wells score, has assisted in clinical decision-making and decreased unnecessary radiological investigations. However, imaging (i.e. computed tomography pulmonary angiography or ventilation-perfusion scans) is still necessary for objective diagnosis. Anti-coagulation remains the foundation of PE management. Haemodynamically unstable patients require thrombolysis unless absolutely contraindicated, while stable patients with right ventricular dysfunction or ischaemia should be aggressively anti-coagulated. Stable patients with no right ventricular dysfunction can be discharged home early with anti-coagulation and review. However, treatment should be case dependent with full consideration of the patient's clinical state. Direct oral anti-coagulants have become an alternative to vitamin K antagonists and are facilitating shorter hospital admissions. Additionally, duration of anti-coagulation must be decided by considering any provoking factors, bleeding risk and comorbid state. Patients with truly unprovoked or idiopathic PE often require indefinite treatment, while in provoked cases it is typically 3 months with some patients requiring longer periods of 6-12 months.

Catheter-directed Thrombolysis for Intermediate-Risk Pulmonary Embolism

Intermediate-risk pulmonary embolism is common and carries a risk of progression to hemodynamic collapse and death. Catheter-directed thrombolysis is an increasingly used treatment option, based largely on the assumptions that it is more efficacious than anticoagulation alone and safer than systemic thrombolysis. In this review, we critically analyze the published data regarding catheter-directed thrombolysis for the treatment of intermediate-risk pulmonary embolism. Catheter-directed thrombolysis reduces right heart strain and lowers pulmonary artery pressures more quickly than anticoagulation alone. The mortality for patients with intermediate-risk pulmonary embolism treated with catheter-directed thrombolysis is low, between 0% and 4%. However, similarly low mortality is seen with anticoagulation alone. Catheter-directed thrombolysis appears to be safer than systemic thrombolysis, and procedural complications are uncommon. Bleeding risk appears to be slightly higher than with anticoagulation alone. Randomized, controlled trials are needed to compare the efficacy and safety of catheter-directed thrombolysis versus anticoagulation for intermediate-risk pulmonary embolism. There is no evidence that catheter-directed thrombolysis decreases the incidence of chronic thromboembolic pulmonary hypertension. There is no evidence from clinical studies that ultrasound-assisted thrombolysis is more effective or safer than standard catheter-directed thrombolysis.

Lifting the fog in intermediate-risk (submassive) PE: full dose, low dose, or no thrombolysis?

Acute pulmonary embolism (PE) is a disease frequently encountered in clinical practice. While the management of haemodynamically stable, low risk patients with acute PE is well established, managing intermediate disease often presents a therapeutic dilemma. In this review, we discuss the various therapeutic options available in this patient group. This includes thrombolysis, surgical embolectomy and catheter directed techniques. We have also explored the role of specialist PE response teams in the management of such patients. ​.

Endovascular therapy for acute severe pulmonary embolism

Acute pulmonary embolism (PE) is a major public health problem and accounts for 100,000-180,000 deaths per year in the United States. Current prognostic stratification separates acute PE into massive, submassive, and low-risk by the presence or absence of sustained hypotension, RV dysfunction, and myocardial necrosis. Massive, submassive and low-risk PE have mortality rates of 25-65%, 3%, and < 1%, respectively. In this review we will focus on therapies currently available to manage acute massive and submassive PE.

Tissue plasminogen activator dose and pulmonary artery pressure reduction in catheter directed thrombolysis of submassive pulmonary embolism

Purpose

The purpose of this study is to assess the incremental effect of tissue plasminogen activator (t-PA) dose on pulmonary artery pressure (PAP) and bleeding during catheter directed thrombolysis (CDT) of submassive pulmonary embolism (PE).

Materials and methods

Records of 46 consecutive patients (25 men, 21 women, mean age 55±14 y) who underwent CDT for submassive PE between September 2009 and February 2017 were retrospectively reviewed. Mean t-PA rate was 0.7±0.3 mg/h. PAP was measured at baseline and daily until CDT termination. Mixed-effects regression modeling was performed of repeated PAP measures in individual patients. Bleeding events were classified by Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) and t-PA dose at onset.

Results

Mean t-PA dose was 43.0±30.0 mg over 61.9± 28.8 h. Mean systolic PAP decreased from 51.7±15.5 mmHg at baseline to 35.6±12.7 mmHg at CDT termination (p<0.001). Mixed-effects regression revealed a linear decrease in systolic PAP over time (β = -0.37 (SE = 0.05), p<0.001) with reduction in mean systolic PAP to 44.8±1.9 mmHg at 12 mg t-PA/20 h, 39.5±2.0 mmHg at 24 mg t-PA/40 h, and 34.9±2.1 mmHg at 36 mg/60 h. No severe, one moderate, and 8 mild bleeding events occurred; bleeding onset was more frequent at ≤24 mg t-PA (p <0.001). One patient expired from cardiopulmonary arrest after 16 h of CDT (15.4 mg t-PA); no additional intra-procedural fatalities occurred.

Conclusion

Increased total t-PA dose and CDT duration were associated with greater PAP reduction without increased bleeding events.

Thrombolytic therapy for pulmonary embolism

BACKGROUND

Thrombolytic therapy is usually reserved for patients with clinically serious or massive pulmonary embolism (PE). Evidence suggests that thrombolytic agents may dissolve blood clots more rapidly than heparin and may reduce the death rate associated with PE. However, there are still concerns about the possible risk of adverse effects of thrombolytic therapy, such as major or minor haemorrhage. This is the third update of the Cochrane review first published in 2006.

OBJECTIVES

To assess the effects of thrombolytic therapy for acute pulmonary embolism.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 16 April 2018. We undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared thrombolytic therapy followed by heparin versus heparin alone, heparin plus placebo, or surgical intervention for patients with acute PE. We did not include trials comparing two different thrombolytic agents or different doses of the same thrombolytic drug.

DATA COLLECTION AND ANALYSIS

Two review authors (JY, QH) assessed the eligibility and quality of trials and extracted data. We calculated effect estimates using the odds ratio (OR) with 95% confidence interval (CI) or the mean difference (MD) with 95% CI. We assessed the quality of the evidence using GRADE criteria.

MAIN RESULTS

We identified no new studies for inclusion in this 2018 update. We included in the review 18 trials with a total of 2197 participants. We were not able to include one study in the meta-analysis because it provided no data that we could extract. Most of the studies carried a high risk of bias because of high or unclear risk related to randomisation and blinding. Meta-analysis showed that, compared with heparin alone, or heparin plus placebo, thrombolytics plus heparin can reduce the odds of death (OR 0.57, 95% CI 0.37 to 0.87, 2167 participants, P = 0.01, low-quality evidence) and recurrence of PE (OR 0.51, 95% CI 0.29 to 0.89, 1898 participants, P = 0.02, low-quality evidence). Effects on mortality weakened when we excluded from analysis four studies at high risk of bias (OR 0.66, 95% CI 0.42 to 1.06, 2054 participants, P = 0.08). The incidence of major and minor haemorrhagic events was higher in the thrombolytics group than in the control group (OR 2.90, 95% CI 1.95 to 4.31, 1897 participants, P < 0.001, low-quality evidence; OR 3.09, 95% CI 1.58 to 6.06, 1553 participants, P = 0.001, very low-quality evidence, respectively). We downgraded the quality of the evidence to low or very low because of design limitations, potential influence of pharmaceutical companies, and small sample sizes. Length of hospital stay (mean difference (MD) -0.89, 95% CI -3.13 to 1.34) and quality of life were similar between the two treatment groups. Limited information from a small number of trials indicated that thrombolytics may improve haemodynamic outcomes, perfusion lung scanning, pulmonary angiogram assessment, echocardiograms, pulmonary hypertension, coagulation parameters, clinical outcomes, and survival time to a greater extent than heparin alone. However, the heterogeneity of the studies and the small number of participants involved warrant caution when results are interpreted. Similarily, fewer participants from the thrombolytics group required escalation of treatment. None of the included studies reported on post-thrombotic syndrome or compared the costs of different treatments.

AUTHORS' CONCLUSIONS

Low-quality evidence suggests that thrombolytics reduce death following acute pulmonary embolism compared with heparin. The included studies used a variety of thrombolytic drugs. Thrombolytic therapy may be helpful in reducing the recurrence of pulmonary emboli but may cause major and minor haemorrhagic events and stroke. More high-quality, blinded randomised controlled trials assessing safety and cost-effectiveness of therapies for pulmonary embolism are required.

Prise en charge de l'embolie pulmonaire grave en réanimation

L'embolie pulmonaire (EP) grave, définie par la présence d’un état de choc, est à l'origine d'une mortalité importante. L'objectif de cette mise au point est de synthétiser les dernières avancées et recommandations concernant la prise en charge des formes graves d'EP. La stratification du risque individuel de mortalité précoce permet d'apporter une stratégie diagnostique et thérapeutique optimisée pour chaque patient. Le traitement symptomatique consiste essentiellement en la prise en charge de l'état de choc. L'anticoagulation curative par héparine non fractionnée est réservée aux patients hémodynamiquement instables. Chez ces patients à haut risque, la thrombolyse systémique diminue la mortalité et le risque de récidive d'EP. Chez les patients à risque intermédiaire élevé, la thrombolyse systémique à dose standard diminue le risque de choc secondaire mais sans impact sur la mortalité globale. La thrombolyse est donc réservée aux patients à risque intermédiaire élevé présentant secondairement un état de choc. L'embolectomie chirurgicale reste indiquée en cas de contre-indication absolue à la thrombolyse ou en cas d'échec de celle-ci. Le positionnement dans l'algorithme thérapeutique de l'assistance extracorporelle et des techniques percutanées de revascularisation reste à définir. Leurs indications doivent donc être discutées dans des centres experts après une concertation multidisciplinaire incluant pneumologues, cardiologues, réanimateurs, radiologues interventionnels et chirurgiens cardiaques.

Contemporary Management of the High-Risk Pulmonary Embolism: The Clot Thickens

Pulmonary embolism (PE) is a common disease process encountered in the acute care setting. It presents on a spectrum of severity with the most severe presentations carrying a substantial risk of morbidity and mortality. In recent years, a wide range of competing treatment strategies have been proposed for the high-risk PE including new catheter-based and extracorporeal techniques, and management has become more challenging. There is currently no consensus as to the optimal approach to treatment. Contemporary management decisions are informed by the balance between the risk of deterioration and the risk of harm from intervention, within the available resources. This review will summarize the current evidence to better inform clinical decision-making in high-risk PE and highlight future directions in management.

Comparison of acute and convalescent biomarkers of inflammation in patients with acute pulmonary embolism treated with systemic fibrinolysis vs. placebo

: Previous studies have associated biomarkers indicative of acute inflammation with pulmonary embolism, which may amplify coagulation, inhibit fibrinolysis and increase risk of venous thromboembolism (VTE) recurrence. The aim of this study was to measure inflammatory and hemostatic biomarkers in acute submassive pulmonary embolism at diagnosis and 3-month follow-up and to test the impact of treatment with fibrinolysis. Secondary analysis of a multicenter, double-blinded, randomized controlled trial including patients with submassive pulmonary embolism. Blood samples were obtained within 24 h of diagnosis and prior to bolus-dose tenecteplase (TNK) or placebo; all patients received standard anticoagulation and blood was redrawn 3 months later. Plasma concentrations of inflammatory [Interleukin 6 (IL-6), C-reactive protein (CRP), myeloperoxidase (MPO)] and hemostatic [plasminogen activator inhibitor-1 (PAI-1), fibrinogen, thrombin-activatable fibrinolysis inhibitor and D-dimer] biomarkers were quantified. The median values of the biomarkers of inflammation (IL-6, CRP, MPO) were all significantly decreased at 3-month follow-up, ranging from a 60 to 91% reduction over this time period. Concentrations of PAI-1 and fibrinogen did not change significantly. D-dimer concentration at 3-month follow-up was lower in patients treated with fibrinolysis vs. placebo and appeared to have a trend toward significance (placebo 310 vs. TNK 220 ng/ml, P = 0.051). Acute pulmonary embolism causes marked but transient inflammation, as demonstrated by the significant elevation in the inflammatory biomarkers at diagnosis, followed by their reduction in more than 80% of patients at 3-month follow-up.

Local low-dose urokinase thrombolysis for the management of haemodynamically stable pulmonary embolism with right ventricular dysfunction

AIMS

The aim of this study was to evaluate the effectiveness of local low-dose urokinase thrombolysis (LLDUT) in haemodynamically stable pulmonary embolism with right ventricular dysfunction (RVD).

METHODS AND RESULTS

This was a prospective study. LLDUT with a 200,000 IU bolus followed by a 100,000 IU/hr infusion was given. Treatment duration was determined through radiological control performed 48-72 hrs into treatment. A follow-up echocardiogram was performed within seven days after LLDUT completion. Evolution of thrombus burden, pulmonary artery pressures (PAP) and RVD were studied, and haemorrhagic complications and mortality were recorded. Eighty-seven patients were included (62.5±16.5 years). In 67 patients (77%), the baseline echocardiogram showed mild-to-severe RVD, a dilated right ventricle (diameter: 44.4±6.2 mm) and a decreased tricuspid annular plane systolic excursion (14 mm [12-17]). Seventy-six patients (87.4%) experienced radiological improvement. Initially high PAP (mmHg) decreased after LLDUT: systolic 52.4 vs. 35.2 (17.2 [95% CI: 14.5-19.9]; p<0.0001), mean 34.2 vs. 23.5 (10.7 [95% CI: 9.0-12.5]; p<0.0001) and diastolic 23.9 vs. 16.0 (7.9 [95% CI: 6.1-9.7]; p<0.0001). Follow-up echocardiography showed overall improvement of RVD. No life-threatening haemorrhagic complications were reported. Six-month survival was 96.5%.

CONCLUSIONS

LLDUT rapidly decreased thrombus burden and PAP, improving right ventricular function, and was not associated with any life-threatening complications or pulmonary embolism (PE)- or treatment-related mortality.

Acute pulmonary embolism: endovascular therapy

Pulmonary embolism (PE) is a leading cause of morbidity and mortality worldwide. PE is a complex disease with a highly variable presentation and the available treatment options for PE are expanding rapidly. Anticoagulation (AC), systemic lysis, surgery, and catheter-directed thrombolysis (CDT) play important roles in treating patients with PE. Thus, a multidisciplinary approach to diagnosis, risk stratification, and therapy is required to determine which treatment option is best for a given patient with this complex disease.

How I use catheter-directed interventional therapy to treat patients with venous thromboembolism

Patients who present with severe manifestations of acute venous thromboembolism (VTE) are at higher risk for premature death and long-term disability. In recent years, catheter-based interventional procedures have shown strong potential to improve clinical outcomes in selected VTE patients. However, physicians continue to be routinely faced with challenging decisions that pertain to the utilization of these risky and costly treatment strategies, and there is a relative paucity of published clinical trials with sufficient rigor and directness to inform clinical practice. In this article, using 3 distinct clinical scenario presentations, we draw from the available published literature describing the natural history, pathophysiology, treatments, and outcomes of VTE to illustrate the key factors that should influence clinical decision making for patients with severe manifestations of deep vein thrombosis and pulmonary embolism. The results of a recently completed pivotal multicenter randomized trial are also discussed.

Venous Thromboembolism and Pulmonary Embolism Response Teams: An Overview

Venous thromboembolism is a common disease with a wide array of signs and symptoms. It has been cited as the third leading cause of cardiovascular death, and if left untreated, it leads to death in 1 in 4 patients. Sophisticated diagnostic tools have allowed physician to become more accurate in diagnosing pulmonary embolism and deep vein thrombosis. The advent of new oral anticoagulants, the emergence of pulmonary embolism response teams, and protocols demonstrate recent achievements in the management of venous thromboembolism. The focus of this article is to discuss the treatment of venous thromboembolism.

Systemic Thrombolysis for Pulmonary Embolism: Who and How

Anticoagulation has been shown to improve mortality in acute pulmonary embolism (PE). Initiation of anticoagulation should be considered when PE is strongly suspected and the bleeding risk is perceived to be low, even if acute PE has not yet been proven. Low-risk patients with acute PE are simply continued on anticoagulation. Severely ill patients with high-risk (massive) PE require aggressive therapy, and if the bleeding risk is acceptable, systemic thrombolysis should be considered. However, despite clear evidence that parenteral thrombolytic therapy leads to more rapid clot resolution than anticoagulation alone, the risk of major bleeding including intracranial bleeding is significantly higher when systemic thrombolytic therapy is administered. It has been demonstrated that right ventricular dysfunction, as well as abnormal biomarkers (troponin and brain natriuretic peptide) are associated with increased mortality in acute PE. In spite of this, intermediate-risk (submassive) PE comprises a fairly broad clinical spectrum. For several decades, clinicians and clinical trialists have worked toward a more aggressive, yet safe solution for patients with intermediate-risk PE. Standard-dose thrombolysis, low-dose systemic thrombolysis, and catheter-based therapy which includes a number of devices and techniques, with or without low-dose thrombolytic therapy, have offered potential solutions and this area has continued to evolve. On the basis of heterogeneity within the category of intermediate-risk as well as within the high-risk group of patients, we will focus on the use of systemic thrombolysis in carefully selected high- and intermediate-risk patients. In certain circumstances when the need for aggressive therapy is urgent and the bleeding risk is acceptable, this is an appropriate approach, and often the best one.

The value of electrocardiography in prognosticating clinical deterioration and mortality in acute pulmonary embolism: A systematic review and meta-analysis

The role of electrocardiography (ECG) in prognosticating pulmonary embolism (PE) is increasingly recognized. ECG is quickly interpretable, noninvasive, inexpensive, and available in remote areas. We hypothesized that ECG can provide useful information about PE prognostication. We searched MEDLINE, EMBASE, Google Scholar, Web of Science, abstracts, conference proceedings, and reference lists through February 2017. Eligible studies used ECG to prognosticate for the main outcomes of death and clinical deterioration or escalation of therapy. Two authors independently selected studies; disagreement was resolved by consensus. Ad hoc piloted forms were used to extract data and assess risk of bias. We used a random-effects model to pool relevant data in meta-analysis with odds ratios (ORs) and 95% confidence intervals (CIs); all other data were synthesized qualitatively. Statistical heterogeneity was assessed using the I ² value. We included 39 studies (9198 patients) in the systematic review. There was agreement in study selection (κ: 0.91, 95% CI: 0.86-0.96). Most studies were retrospective; some did not appropriately control for confounders. ECG signs that were good predictors of a negative outcome included S1Q3T3 (OR: 3.38, 95% CI: 2.46-4.66, P < 0.001), complete right bundle branch block (OR: 3.90, 95% CI: 2.46-6.20, P < 0.001), T-wave inversion (OR: 1.62, 95% CI: 1.19-2.21, P = 0.002), right axis deviation (OR: 3.24, 95% CI: 1.86-5.64, P < 0.001), and atrial fibrillation (OR: 1.96, 95% CI: 1.45-2.67, P < 0.001) for in-hospital mortality. Several ischemic patterns also were significantly predictive. Our conclusion is that ECG is potentially valuable in prognostication of acute PE.

A Pulmonary Embolism Response Team: initial experiences and future directions

INTRODUCTION

Acute pulmonary embolism (PE) is a common cardiovascular condition resulting in significant morbidity and mortality. Consensus recommendations suggest risk stratification of patients into three main categories: high-risk or 'massive' PE, intermediate-risk or 'submassive' PE, and low-risk PE. Given the relative dearth of prospective, randomized clinical trials delineating optimal selection of the diverse medical, interventional, and surgical treatment approaches, clinical care requires a multidisciplinary expert approach to patients with PE. Areas covered: The Massachusetts General Hospital (MGH) Pulmonary Embolism Response Team (PERT) was the first of its kind to create a multidisciplinary, rapid response team for acute PE, integrated within a research and educational framework. The MGH PERT has treated more than 700 patients with PE, the majority of which are in the 'massive' or 'submassive' categories. The PERT Consortium™ was founded in 2015 as a collaborative network between the growing number of PERT programs internationally, with greater than 80 institutions participating within one year of establishment. Expert commentary: Since its advent, the PERT model has expanded throughout the United States and internationally through a collaborative institutional and research network. PERT may represent a new standard for the care of patients with acute PE.

Variable Resistance to Plasminogen Activator Initiated Fibrinolysis for Intermediate-Risk Pulmonary Embolism

Background

We examine the clinical significance and biomarkers of tissue plasminogen activator (tPA)-catalyzed clot lysis time (CLT) in patients with intermediate-risk pulmonary embolism (PE).

Methods

Platelet-poor, citrated plasma was obtained from patients with PE. Healthy age- and sex-matched patients served as disease-negative controls. Fibrinogen, α₂-antiplasmin, plasminogen, thrombin activatable fibrinolysis inhibitor (TAFI), plasminogen activator Inhibitor 1 (PAI-1), thrombin time and D-dimer were quantified. Clotting was induced using CaCl₂, tissue factor, and phospholipid. Lysis was induced using 60 ng/mL tPA. Time to 50% clot lysis (CLT) was assessed by both thromboelastography (TEG) and turbidimetry (A405).

Results

Compared with disease-negative controls, patients with PE exhibited significantly longer mean CLT on TEG (+2,580 seconds, 95% CI 1,380 to 3,720 sec). Patients with PE and a short CLT who were treated with tenecteplase had increased risk of bleeding, whereas those with long CLT had significantly worse exercise tolerance and psychometric testing for quality of life at 3 months. A multivariate stepwise removal regression model selected PAI-1 and TAFI as predictive biomarkers of CLT.

Conclusion

The CLT from TEG predicted increased risk of bleeding and clinical failure with tenecteplase treatment for intermediate-risk PE. Plasmatic PAI-1 and TAFI were independent predictors of CLT.

Potential role of systemic thrombolysis in acute submassive intermediate risk pulmonary embolism: review and future perspectives

Submassive (intermediate risk) pulmonary embolism (PE) continues to be a significantly morbid disease process that remains unrecognized, inadequately risk stratified and suboptimally treated. Appropriate early clinical and imaging-based risk stratification represents the cornerstone for adequate therapeutic decision making, particularly for the selection of candidates who may benefit the most from systemic thrombolysis. The relevance of estimating clinical prognostic scores, in combination with imaging data, for accurate assessment of right ventricular function and laboratory biomarkers, indicative of myocardial injury for identification of normotensive patients at intermediate risk for an adverse short-term outcome are emphasized in this review. Recent clinical trials have demonstrated improvement in hemodynamics and mortality with the use of systemic thrombolysis among intermediate risk patients; however, it came at the cost of a significantly increased risk of major bleeding. Catheter-based therapies have garnered considerable clinical interest in recent years; of particular note is the ultrasound accelerated catheter-directed thrombolysis which has emerged as a novel and attractive alternative therapeutic modality with an increasing number of single center studies and ongoing randomized trials. Our review focuses on the major trials and studies involved in submassive PE in the recent literature including the role of thrombolytic therapy. We include major trials with reasonable sample size and extensive review of the potential side effects, such as major bleeding.

Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report

BACKGROUND

We update recommendations on 12 topics that were in the 9th edition of these guidelines, and address 3 new topics.

METHODS

We generate strong (Grade 1) and weak (Grade 2) recommendations based on high- (Grade A), moderate- (Grade B), and low- (Grade C) quality evidence.

RESULTS

For VTE and no cancer, as long-term anticoagulant therapy, we suggest dabigatran (Grade 2B), rivaroxaban (Grade 2B), apixaban (Grade 2B), or edoxaban (Grade 2B) over vitamin K antagonist (VKA) therapy, and suggest VKA therapy over low-molecular-weight heparin (LMWH; Grade 2C). For VTE and cancer, we suggest LMWH over VKA (Grade 2B), dabigatran (Grade 2C), rivaroxaban (Grade 2C), apixaban (Grade 2C), or edoxaban (Grade 2C). We have not changed recommendations for who should stop anticoagulation at 3 months or receive extended therapy. For VTE treated with anticoagulants, we recommend against an inferior vena cava filter (Grade 1B). For DVT, we suggest not using compression stockings routinely to prevent PTS (Grade 2B). For subsegmental pulmonary embolism and no proximal DVT, we suggest clinical surveillance over anticoagulation with a low risk of recurrent VTE (Grade 2C), and anticoagulation over clinical surveillance with a high risk (Grade 2C). We suggest thrombolytic therapy for pulmonary embolism with hypotension (Grade 2B), and systemic therapy over catheter-directed thrombolysis (Grade 2C). For recurrent VTE on a non-LMWH anticoagulant, we suggest LMWH (Grade 2C); for recurrent VTE on LMWH, we suggest increasing the LMWH dose (Grade 2C).

CONCLUSIONS

Of 54 recommendations included in the 30 statements, 20 were strong and none was based on high-quality evidence, highlighting the need for further research.

Guidance for the use of thrombolytic therapy for the treatment of venous thromboembolism

Patients with venous thromboembolism (VTE) are prone to the development of both short-term and long-term complications that can substantially affect their functional capacity and quality of life. Patients with deep vein thrombosis (DVT) often develop recurrent VTE or the post-thrombotic syndrome, whereas patients with pulmonary embolism (PE) can develop long-term symptoms and functional limitations along a broad spectrum extending to full-blown chronic thromboembolic pulmonary hypertension. Clinicians who care for patients showing severe clinical manifestations of DVT and PE are often faced with challenging decisions concerning whether and how to escalate to more aggressive treatments such as those involving the use of thrombolytic drugs. The purpose of this chapter is to provide guidance on how best to individualize care to these patients.