Fixed low-dose ultrasound-assisted catheter-directed thrombolysis for intermediate and high-risk pulmonary embolism

Comparison of Safety and Efficacy of Aspiration Thrombectomy and Ultrasound Accelerated Thrombolysis for Management of Pulmonary Embolism: A Systematic Review and Meta-Analysis

PURPOSE

To compare the safety and efficacy of mechanical thrombectomy (MT) and ultrasound-accelerated thrombolysis (USAT) in pulmonary embolism (PE) management by performing a systematic review of the literature.

MATERIALS AND METHODS

The PubMed database was searched to identify articles on Inari's FlowTriever and Penumbra's Indigo mechanical thrombectomy devices (Group A) and the Ekos Endovascular system (Group B). Outcomes variables analyzed include pre- and post-procedure RV/LV ratio, pre- and post-procedure pulmonary artery pressure, hospital length of stay, technical success, specific complications, and mortality rate. Mean values were calculated using the weighted mean approach. RevMan Version 5.4 (Cochrane Collaboration) was used to perform the meta-analysis for this study. Cochrane Collaboration's Risk of Bias (RoB 2.0) approach was used to perform a quality assessment of the included articles in order to verify the validity and reliability of the research.

RESULTS

27 studies were in Group A and 28 studies pertained to Group B. There were 1662 patients in Group A and 1273 patients in Group B. Both groups had similar technical success (99.6% vs 99.4%). Thrombectomy showed longer mean procedure time (73.03 ± 14.57 min vs 47.35 ± 3.15 min), lower mean blood loss (325.20 ± 69.15 mL vs 423.05 ± 64.95 mL), shorter mean ICU stay (2.35 ± 1.64 days vs 3.22 ± 1.27 days), and shorter mean overall hospital stay (6.94 ± 4.38 days vs 7.23 ± 2.31 days). EKOS showed greater mean change in Miller Index (9.05 ± 3.35 vs 4.91 ± 3.70) and greater mean change in pulmonary artery pressure (14.17 ± 6.35 mmHg vs 8.11 ± 4.39 mmHg).

CONCLUSION

Ultrasound accelerated thrombolysis and percutaneous mechanical thrombectomy are effective therapies for pulmonary embolism with comparable clinical outcomes.

Episode Care Costs Following Catheter-Directed Reperfusion Therapies for Pulmonary Embolism: A Literature-Based Comparative Cohort Analysis

This analysis aimed to estimate 30-day episode care costs associated with 3 contemporary endovascular therapies indicated for treatment of pulmonary embolism (PE). Systematic literature review was used to identify clinical research reporting costs associated with invasive PE care and outcomes for ultrasound-accelerated thrombolysis (USAT), continuous-aspiration mechanical thrombectomy (CAMT), and volume-controlled-aspiration mechanical thrombectomy (VAMT). Total episode variable care costs were defined as the sum of device costs, variable acute care costs, and contingent costs. Variable acute care costs were estimated using methodology sensitive to periprocedural and postprocedural resource allocation unique to the 3 therapies. Contingent costs included expenses for thrombolytics, postprocedure bleeding events, and readmissions through 30 days. Through February 28, 2023, 70 sources were identified and used to inform estimates of 30-day total episode variable costs. Device costs for USAT, CAMT, and VAMT were the most expensive single component of total episode variable costs, estimated at $5,965, $10,279, and $11,901, respectively. Costs associated with catheterization suite utilization, intensive care, and hospital length of stay, along with contingent costs, were important drivers of total episode costs. Total episode variable care costs through 30 days were $19,146, $20,938, and $17,290 for USAT, CAMT, and VAMT, respectively. In conclusion, estimated total episode care costs after invasive treatment for PE are heavily influenced by device expense, in-hospital care, and postacute care complications. Regardless of device cost, strategies that avoid thrombolytics, reduce the need for intensive care unit care, shorten length of stay, and reduce postprocedure bleeding and 30-day readmissions contributed to the lowest episode costs.

First Experience With Catheter-Directed Thrombolysis for Massive Pulmonary Embolism at Teaching Hospital Jaffna, Sri Lanka: A Case Report

Catheter-directed thrombolysis (CDT) is one of the modes of treatment for massive pulmonary embolism (PE). This case report shares the new experience of CDT for massive PE at Teaching Hospital Jaffna, Sri Lanka. A 54-year-old woman developed massive PE two days after a traumatic tibial fracture. She was hemodynamically unstable with hypotension and hypoxemia. The multidisciplinary team decided to go for CDT, administering alteplase. Follow-up imaging demonstrated complete thrombus resolution and significant clinical improvement. This case emphasizes the efficacy and safety of CDT for massive PE, particularly in patients at high risk for bleeding. Our experience at Teaching Hospital Jaffna accentuates the significance of individualized treatment strategies and the adoption of advanced techniques in resource-limited settings.

Accuracy of VO2 estimation according to the widely used Krakau formula for the prediction of cardiac output

BACKGROUND

Invasive cardiac output (CO) is measured with the thermodilution (TD) or the indirect Fick method (iFM) in right heart catheterization (RHC). The iFM estimates CO using approximation formulas for oxygen consumption ([Formula: see text]O2), but there are significant discrepancies (> 20%) between both methods. Although regularly applied, the formula proposed by Krakau has not been validated. We compared the CO discrepancies between the Krakau formula with the reference (TD) and three established formulas and investigated whether alterations assessed in cardiac magnetic resonance imaging (CMR) determined the extent of the deviations.

METHODS

This retrospective study included 188 patients aged 63 ± 14 years (30% women) receiving both CMR and RHC. The CO was measured with TD or with the iFM using the formulas by Krakau, LaFarge, Dehmer, and Bergstra for [Formula: see text]O2 estimation (iFM-K/-L/-D/-B). Percentage errors were calculated as twice the standard deviation of the difference between two CO methods divided by their means; a cut-off of < 30% was regarded as acceptable. The iFM and TD-derived CO ratio was built, and deviations > 20% were counted. Logistic regression analyses were performed to identify determinants of a deviation of > 20%.

RESULTS

The TD-derived CO (5.5 ± 1.7 L/min) was significantly different from all iFM (K: 4.8 ± 1.6, L: 4.3 ± 1.6; D: 4.8 ± 1.5 L/min; B: 5.4 ± 1.8 L/min all p < 0.05). The iFM-K-CO differed from all methods (p < 0.001) except iFM‑D (p = 0.19). Percentage errors between TD-CO and iFM-K/-L/-D/-B were all beyond the acceptance limit (44/45/44/43%), while percentage errors between iFM‑K and other iFM were all < 16%. None of the parameters measured in CMR was predictive of a discrepancy of > 20% between both methods.

CONCLUSION

The Krakau formula was comparable to other iFM in estimating CO levels, but none showed satisfactory agreement with the TD method. Improved derivation cohorts for [Formula: see text]O2 estimation are needed that better reflect today's patients undergoing RHC.

Current Diagnosis and Management of Acute Pulmonary Embolism: A Strategy for General Practitioners in Emergency Department

Pulmonary embolism (PE) is a disease with a relatively good prognosis when diagnosed and treated properly. This review aims to analyse available data and combine them into algorithms that physicians can use in the emergency department for quick decision-making in diagnosing and treating PE. The available data show that PE can be excluded through highly sensitive clinical decision rules, i.e. Pulmonary Embolism Rule-Out Criteria (PERC), Wells criteria, and Revised Geneva criteria, combined with D-dimer assessment. In cases where PE could not be excluded through the mentioned strategies, imaging modalities, such as compression ultrasonography (CUS), computed tomographic pulmonary angiography (CTPA), and planar ventilation/perfusion (V/Q) scan, are indicated for a definite diagnosis. Once a diagnosis has been made, treatment of PE depends on its mortality risk as patients are divided into low-, intermediate-, and high-risk cases. High-risk cases are treated for their hemodynamic instability, given parenteral or oral anticoagulant therapy, and are indicated for reperfusion therapy. Intermediate-risk PE is only given parenteral or oral anticoagulants and reperfusion is indicated when anticoagulants fail. Low-risk cases are given oral anticoagulants and based on the Hestia criteria, patients may be discharged and treated as outpatients.

An Update on the Management of Acute High-Risk Pulmonary Embolism

Hemodynamic instability and right ventricular (RV) dysfunction are the key determinants of short-term prognosis in patients with acute pulmonary embolism (PE). High-risk PE encompasses a wide spectrum of clinical situations from sustained hypotension to cardiac arrest. Early recognition and treatment tailored to each individual are crucial. Systemic fibrinolysis is the first-line pulmonary reperfusion therapy to rapidly reverse RV overload and hemodynamic collapse, at the cost of a significant rate of bleeding. Catheter-directed pharmacological and mechanical techniques ensure swift recovery of echocardiographic parameters and may possess a better safety profile than systemic thrombolysis. Further clinical studies are mandatory to clarify which pulmonary reperfusion strategy may improve early clinical outcomes and fill existing gaps in the evidence.

An Eight-year, Single-center Experience on Ultrasound Assisted Thrombolysis with Moderate-dose, Slow-infusion Regimen in Pulmonary Embolism

BACKGROUND

There is limited data on moderate-dose with slow-infusion thrombolytic regimen by ultrasound-asssisted-thrombolysis (USAT) in patients with acute pulmonary embolism (PE).

AIMS

In this study, our eight-year experience on USAT with moderate-dose, slow-infusion tissue-type plasminogen activator (t-PA) regimen in patients with PE at intermediate-high- and high-risk was presented, and short-, and long-term effectiveness and safety outcomes were evaluated.

METHODS

Our study is based on the retrospective evaluation of 225 patients with PE having multiple comorbidities who underwent USAT.

RESULTS

High- and intermediate-high-risk were noted in 14.7% and in 85.3% of patients, respectively. Mean t-PA dosage was 35.4±13.3 mg, and the infusion duration was 26.6±7.7 h. Measures of pulmonary artery (PA) obstruction and right ventricle (RV) dysfunction were improved within days (p<0.0001 for all). During the hospital stay, major and minor bleeding and mortality rates were 6.2%, 12.4%, and 6.2%, respectively. Bleeding and unresolved PE accounted for 50% and 42.8% of in-hospital mortality, respectively. Age, rate, and duration of t-PA were not associated with in-hospital major bleeding and mortality. Oxygen saturation exceeded 90% in 91.2% of patients at discharge. During follow-up of median 962 (610-1894) days, high-risk status related to 30-day mortality, whereas age >65 years was associated with long-term mortality.

CONCLUSION

Our real-life experience with USAT with moderate-dose, slow-infusion t-PA regimen in patients with PE at high-and intermediate-high risk demonstrated clinically relevant improvements in PA obstructive burden and RV dysfunction. Age, rate or infusion duration of t-PA was not related to major bleeding or mortality risk, whereas unresolved obstruction remained as a lethal issue.

Catheter-Directed Therapies in Patients with Pulmonary Embolism: Predictive Factors of In-Hospital Mortality and Long-Term Follow-Up

(1) Background: Catheter-directed therapies (CDT) may be considered for selected patients with pulmonary embolism (PE); (2) Methods: Retrospective observational study including all consecutive patients with acute PE undergoing CDT (mechanical or pharmacomechanical) from January 2010 through December 2020. The aim was to evaluate in-hospital and long-term mortality and its predictive factors; (3) Results: We included 63 patients, 43 (68.3%) with high-risk PE. All patients underwent mechanical CDT and, additionally, 27 (43%) underwent catheter-directed thrombolysis. Twelve (19%) patients received failed systemic thrombolysis (ST) prior to CDT, and an inferior vena cava (IVC) filter was inserted in 28 (44.5%) patients. In-hospital PE-related and all-cause mortality rates were 31.7%; 95% CI 20.6-44.7% and 42.9%; 95% CI 30.5-56%, respectively. In multivariate analysis, age > 70 years and previous ST were strongly associated with PE-related and all-cause mortality, while IVC filter insertion during the CDT was associated with lower mortality rates. After a median follow-up of 40 (12-60) months, 11 more patients died (mortality rate of 60.3%; 95% CI 47.2-72.4%). Long-term survival was significantly higher in patients who received an IVC filter; (4) Conclusions: Age > 70 years and failure of previous ST were associated with mortality in acute PE patients treated with CDT. In-hospital and long-term mortality were lower in patients who received IVC filter insertion.

The Use of POCUS to Manage ICU Patients With COVID-19

Since the advent of SARS-CoV-2, the virus that causes COVID-19, clinicians have had to modify how they provide high-value care while mitigating the risk of viral spread. Routine imaging studies have been discouraged due to elevated transmission risk. Patients who have been diagnosed with COVID-19 often have a protracted hospital course with progression of disease. Given the need for close follow-up of patients, we recommend the use of ultrasonography, particularly point-of-care ultrasound (POCUS), to manage patients with COVID-19 through their entire ICU course. POCUS will allow a clinician to evaluate and monitor cardiac and pulmonary function, as well as evaluate for thromboembolic disease, place an endotracheal tube, confirm central venous catheter placement, and rule out a pneumothorax. If a patient improves sufficiently to perform weaning trials, POCUS can also help evaluate readiness for ventilator liberation.

Catheter directed compared to systemically delivered thrombolysis for pulmonary embolism: a systematic review and meta-analysis

To compare the efficacy and safety of systemic and catheter directed thrombolysis for patients with pulmonary embolism. Pubmed and Cochrane Central Register of Controlled Trials were systematically searched from inception to May 31st 2020 to identify relevant studies. Outcomes of interest were in-hospital mortality and major bleeding including intracranial hemorrhage. We included 8 observational studies comprising 11,932 patients with PE. Catheter directed thrombolysis was associated with lower in-hospital mortality [RR 0.52; 95% confidence interval (CI) 0.40-0.68]. Although there was no difference in major bleeding by treatment strategy (RR 0.80; 95% CI 0.37-1.76), intracranial hemorrhage was lower in patients receiving catheter directed therapy (RR 0.66; 95% CI, 0.47-0.94).The certainty in these estimates was low. Non-randomized studies suggest that catheter directed delivery of thrombolytic therapy may be associated with lower in-hospital mortality and intracranial hemorrhage rates. These results may help inform management strategies for health care and pulmonary embolism response teams (PERT) involved in the management of high risk patients with massive or submassive pulmonary emboli.

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.

Clinical Outcomes of Intermediate-Risk Pulmonary Embolism Across a Northeastern Health System: A Multi-Center Retrospective Cohort Study

OBJECTIVE

The role of thrombolytic therapy in the management of intermediate-risk pulmonary embolism is controversial. Our objective was to determine clinical outcomes for a population of patients with intermediate-risk pulmonary embolism receiving anticoagulation with and without thrombolytic therapy in a large Northeastern health system.

DESIGN

A retrospective cohort study.

SETTING

ICU and non-ICU settings in 8 hospitals.

PATIENTS

Hemodynamically stable patients with intermediate-risk pulmonary embolism.

INTERVENTIONS

Treatment arms were anticoagulation (AC) alone, AC with low dose intravenous thrombolysis, AC with full-dose intravenous thrombolysis, and AC with ultrasound-assisted, catheter-directed thrombolysis.

MEASUREMENTS AND MAIN RESULTS

In 257 patients, utilizing a Bonferroni corrected P value cutoff of α = 0.003, our data shows no differences in 7 day or 30 day all-cause mortality (α = 0.37 and α = 0.04, respectively) , hospital length of stay (α = 0.31), 7 or 30 readmission rates (α = 0.97 and α = 0.84, respectively), or any major (α = 0.82) or minor bleeding events (α = 0.007) among the four treatment groups. Use of anticoagulation alone was associated with a lower duration of ICU stay (α < 0.001). There was a significant decrease in the secondary outcome of one year all-cause mortality in favor of full dose and catheter-directed thrombolytic treatment (α = 0.003). Pulmonary artery systolic pressure of > 70 mmHg was associated with increased 7-day mortality (OR 7.79, P = 0.048), and systolic blood pressure < 130 (OR 23.0; P = 0.003) and elevated N-terminal pro-B-type natriuretic peptide > 1400 pg/nl (OR 15.33; P = 0.01) were associated with increased 30- day mortality.

CONCLUSIONS

The use of thrombolytic therapy is not associated with a mortality benefit in the first 30 days compared to anticoagulation alone in this patient population and is associated with increased utilization of intensive care unit resources. We advocate for a conservative approach utilizing initial anticoagulation alone in a patient diagnosed with intermediate-risk pulmonary embolism.

Hemodynamic Effects of Ultrasound-Assisted, Catheter-Directed, Very Low-Dose, Short-Time Duration Thrombolysis in Acute Intermediate-High Risk Pulmonary Embolism (from the EKOS-PL Study)

Ultrasound-assisted, catheter-directed, low-dose thrombolysis (USAT) at an average alteplase dose of 20 mg infused over 12 to 24 hours reversed right ventricular disfunction and improved pulmonary hemodynamics in intermediate-high-risk pulmonary embolism patients. As bleeding risk increases with the thrombolytic dose, establishing a minimal effective USAT dosing regimen is of clinical importance. We aimed to investigate hemodynamic effects and safety of a very low-alteplase-dose USAT of 10 mg administered within 5 hours. We included 12 consecutive intermediate-high-risk pulmonary embolism patients with symptoms duration of <14 days and proximal thrombi location in pulmonary arteries. Pulmonary Embolism Response Team decision-based fixed, bilateral ultrasound-assisted alteplase infusions at the rate of 1mg/hour/catheter for 5 hours through EKOS system catheters were made. The primary efficacy measure was the change in invasive systolic and mean pulmonary arteries pressure, and in cardiac index from USAT start to termination. Safety measures were 180-day all-cause death or cardiopulmonary decompensation and bleeding complications. The systolic pulmonary arteries pressure and mean pulmonary arteries pressure decreased from 53 (45.5 to 59) to 37.5 (27.5 to 40.5) mm Hg (p = 0.02) and from 29.5 (27.5 to 32) to 21.5 (15.5 to 25) mm Hg (p = 0.02), respectively. The cardiac index increased from 1.6 (1.5 to 1.8) to 2.2 (1.9 to 2.4) l/min/m², (p = 0.02). No deaths, decompensations, or need for therapy intensification occurred. There was 1 episode of access-site bleeding, which subsided after conservative management. No intracranial hemorrhages appeared. In conclusion, reduced dose and duration USAT improved pulmonary hemodynamics and cardiac function leading to cardiopulmonary stabilization in intermediate-high risk pulmonary embolism patients at a low periprocedural risk.

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.

Management of Acute Pulmonary Embolism in a Patient with Sickle Cell Anemia Using Catheter-Directed Thrombolysis

The efficacy of thrombolytic therapy in submassive pulmonary embolism (PE) management is lacking, particularly in specific patient subgroups. The current case report demonstrates the use of catheter-directed thrombolysis (CDT) therapy in conjunction with standard systemic anticoagulation in a patient with sickle cell disease presenting with a submassive PE and chronic thrombus burden. CDT may potentially play a role in the management of submassive PE in sickle cell patients.

Percutaneous thrombectomy in patients with massive and very high-risk submassive acute pulmonary embolism

OBJECTIVE

Examine FlowTriever thrombectomy feasibility in high-risk PE patients.

BACKGROUND

The FlowTriever thrombectomy system (Inari Medical, Irvine, CA) can reduce right ventricle (RV) strain in acute submassive pulmonary embolism (PE) patients. This technology has not been studied in higher risk PE patients.

METHODS

This multicenter retrospective analysis included patients treated with FlowTriever between 2017 and 2019 if they met at least one of the following: vasopressor dependence, PE induced respiratory failure, or decreased cardiac index (CI) measured by right heart catheterization.

RESULTS

Analysis included 34 patients: 18 massive, four intubated, 12 normotensive but with CI < 1.8. Average age was 56 and their median simplified PE severity index was 2. Patients had high bleeding risk, with 13 having recent surgery, six posttrauma, and four recent strokes. Six patients received cardiopulmonary resuscitation, and two received additional mechanical circulatory support. All patients had RV dilatation and elevated biomarkers. Clot removal was successful in 32/34 patients. CI improved from 2.0 ± 0.1 L/min/m² before thrombectomy to 2.4 ± 0.1 L/min/m² after (p = .01). The mean pulmonary artery pressure decreased from 33.2 ± 1.6 mmHg to 25.0 ± 1.5 mmHg (p = .01). The two patients-both with no or minimal thrombus removed-deteriorated during the procedure: one died and the other was successfully stabilized on ECMO. There were no other major complications. All other patients were alive at the time of data collection (mean follow-up of 205 days).

CONCLUSION

Aspiration thrombectomy appears feasible in higher risk acute PE patients with immediate hemodynamic improvement and low in-hospital mortality.

Feasibility of ultrasound-assisted catheter-directed thrombolysis for submassive pulmonary embolism: A meta-analysis of case series

BACKGROUND

During the past few years, there has been a surge in the use of ultrasound-assisted catheter-directed thrombolysis (UACDT) for submassive pulmonary embolism (SPE). However, few studies evaluated the feasibility of UACDT for SPE.

PURPOSE

To evaluate the feasibility of UACDT in treating SPE.

METHODS

A comprehensive search of online databases was performed. Search terms UACDT in SPE were entered into PubMed, Embase, Scopus and the Cochrane Library to identify related articles published until October 2018. A quality assessment and data extraction were performed by two researchers. Meta-analysis was performed using R statistical software.

RESULTS

Twelve studies with 485 patients were included in this meta-analysis. The pooled right ventricular/left ventricular ratio decrease and pulmonary artery systolic pressure drop after treatment was -0.34 (95% CI: -0.43, -0.25) and -15.05 (95% CI: -18.10, -12.00) mm Hg, respectively. The pooled major bleeding rate was 1.0% (95% CI: 0.0%, 3.0%), and the in-hospital mortality was 0.0% (95% CI: 0.0%, 1.0%).

CONCLUSION

This up to data meta-analysis confirms that UACDT is a feasible treatment for SPE.

Local Thrombolysis in High-Risk Pulmonary Embolism-13 Years Single-Center Experience

To evaluate the prognosis after local thrombolysis compared to systemic thrombolysis in high-risk pulmonary embolism. Observational study during 13 years which included 37 patients with high-risk pulmonary embolism treated with local thrombolysis and 36 patients with systemic thrombolysis (streptokinase, 250 000 UI/30 minutes followed by 100 000 UI/h). Cardiogenic shock has totally remitted in the group with local thrombolysis (P = .002). The decrease in pressure gradient between right ventricle and right atrium was comparable in both groups in the acute period (the results being influenced by the higher in-hospital mortality after systemic thrombolysis), but significantly better in the next 24 months follow-up after in situ thrombolysis. Major and minor bleeding did not have significant differences. In hospital, mortality was significantly lower in the group with local thrombolysis (P = .003), but for the next 24 months follow-up, the survival was comparable in both groups. Local thrombolysis, during the hospitalization, was associated with lower mortality rate comparing with systemic thrombolysis. In the next 24 months follow-up, the evolution of residual pulmonary hypertension was significantly better after in situ thrombolysis.

Catheter-directed therapy for acute pulmonary embolism: navigating gaps in the evidence

Systemic thrombolysis for acute pulmonary embolism (PE) reduces the risk of death and cardiovascular collapse but is associated with an increased rate of bleeding. The desire to minimize the risk of bleeding events has driven the development of catheter-based strategies for pulmonary reperfusion in PE. These catheter-based strategies utilize lower-dose fibrinolytic regimens or purely mechanical techniques to expedite removal of the embolus. Several devices providing mechanical or suction embolectomy and catheter-directed thrombolysis, with or without facilitation by ultrasound, have been tested. Data are inconsistent regarding the efficacy and safety of mechanical and suction embolectomy. The most comprehensive data on catheter-based techniques stem from trials of ultrasound-facilitated catheter fibrinolysis. Ultrasound-facilitated catheter fibrinolysis relieves right ventricular pressure overload with a lower risk of major bleeding and intracranial haemorrhage than historical rates with systemic fibrinolysis. However, further research is required to determine the optimal application of ultrasound-facilitated catheter fibrinolysis and other catheter-based therapies in patients with acute PE.

A Randomized Trial of the Optimum Duration of Acoustic Pulse Thrombolysis Procedure in Acute Intermediate-Risk Pulmonary Embolism: The OPTALYSE PE Trial

OBJECTIVES

The aim of this study was to determine the lowest optimal tissue plasminogen activator (tPA) dose and delivery duration using ultrasound-facilitated catheter-directed thrombolysis (USCDT) for the treatment of acute intermediate-risk (submassive) pulmonary embolism.

BACKGROUND

Previous trials of USCDT used tPA over 12 to 24 h at doses of 20 to 24 mg for acute pulmonary embolism.

METHODS

Hemodynamically stable adults with acute intermediate-risk pulmonary embolism documented by computed tomographic angiography were randomized into this prospective multicenter, parallel-group trial. Patients received treatment with 1 of 4 USCDT regimens. The tPA dose ranged from 4 to 12 mg per lung and infusion duration from 2 to 6 h. The primary efficacy endpoint was reduction in right ventricular-to-left ventricular diameter ratio by computed tomographic angiography. A major secondary endpoint was embolic burden by refined modified Miller score, measured on computed tomographic angiography 48 h after initiation of USCDT.

RESULTS

One hundred one patients were randomized, and improvements in right ventricular-to-left ventricular diameter ratio were as follows: arm 1 (4 mg/lung/2 h), 0.40 (24%; p = 0.0001); arm 2 (4 mg/lung/4 h), 0.35 (22.6%; p = 0.0001); arm 3 (6 mg/lung/6 h), 0.42 (26.3%; p = 0.0001); and arm 4 (12 mg/lung/6 h), 0.48 (25.5%; p = 0.0001). Improvement in refined modified Miller score was also seen in all groups. Four patients experienced major bleeding (4%). Of 2 intracranial hemorrhage events, 1 was attributed to tPA delivered by USCDT.

CONCLUSIONS

Treatment with USCDT using a shorter delivery duration and lower-dose tPA was associated with improved right ventricular function and reduced clot burden compared with baseline. The major bleeding rate was low, but 1 intracranial hemorrhage event due to tPA delivered by USCDT did occur.

Meta-Analysis of Catheter Directed Ultrasound-Assisted Thrombolysis in Pulmonary Embolism

Ultrasound-assisted catheter directed thrombolysis (USAT) has been shown to improve hemodynamic function and reduce bleeding complications in patients with acute massive or submassive pulmonary embolism. We performed a meta-analysis to better evaluate the efficacy and safety of USAT. We conducted an extensive literature search in PUBMED, MEDLINE, and EMBASE databases from January 1, 2008 to December 31, 2018. Efficacy outcomes of interest were pulmonary artery systolic pressure, mean pulmonary pressure, ratio of right ventricular to left ventricular diameter, cardiac index, tricuspid annular plane systolic excursion, Miller Index Score, and Qanadli Score. Safety outcomes were in-hospital mortality, long-term mortality, major and minor bleeding complications, and recurrent pulmonary embolism. Meta-analysis was performed using Cochrane Collaboration Review Manager (version 5.1). Effect size was estimated using random effects model, with 95% confidence intervals (CIs). Twenty-eight studies (n = 2,135) met inclusion criteria. Compared with pretreatment parameters, post-USAT was associated with a reduction in the mean Miller Index Score and Qanadli Score by 10.55 (95% CI -12.98 to -8.12) and 15.64 (95% CI -19.08 to -12.20), respectively. Cardiac index and tricuspid annular plane systolic excursion improved by 0.68 L/m² (95% CI 0.49 to 0.87) and 3.68 mm (95% CI 2.43 to 4.93), respectively. Pulmonary artery systolic pressure and mean pulmonary pressure after therapy were reduced by a mean difference of 16.69 mm Hg (95% CI -19.73 to -13.65) and 12.13 mm Hg (95% CI -14.67 to -9.59) respectively. The right ventricular to left ventricular diameter dimension ratio decreased by 0.35 (95% CI -0.40 to -0.30) after therapy. In-hospital mortality in patients who underwent USAT was 2.9%, and total long-term mortality was 4.1%. Major and minor bleeding complications were seen in in 5.4% and 6.0% of patients, respectively. Recurrent events occurred in 0.2% of patients after USAT. In conclusion, USAT is a safe and effective procedure associated with significant hemodynamic and clinical improvement in patients with massive and submassive pulmonary embolism.

Is there an optimal "door to cath time" in the treatment of acute pulmonary embolism with catheter-directed thrombolysis?

Ultrasound assisted catheter-directed thrombolysis (UACT) is a relatively novel approach to treating acute pulmonary embolism (PE). It is an alternative to systemic thrombolysis with good success rates and low reported in-hospital mortality, and low rates of procedure-related major and minor bleeding. Since UACT received FDA approval for the treatment of PE in 2014, there is paucity of data regarding the optimal timing of initiation of the procedure after the initial diagnosis is made. We reviewed the available literature regarding UACT for acute PE and found six studies that included time to procedure. Based on our review, patients may benefit from early (<24-48 h after presentation) rather than delayed (>48 h) initiation. Early initiation of therapy has shown to improve pulmonary arterial pressures, right ventricular (RV) to left ventricular (LV) ratios, with low rates of bleeding and low post procedural and in hospital mortality. However, further studies are required to confirm these findings and establish the appropriate timeline for initiation of UACT.

Submassive Pulmonary Embolism

Pulmonary embolism (PE) presents a spectrum of hemodynamic consequences, ranging from being asymptomatic to a life-threatening medical emergency. Management of submassive and massive PE often involves clinicians from multiple specialties, which can potentially delay the development of a unified treatment plan. In addition, patients with submassive PE can deteriorate after their presentation and require escalation of care. Underlying comorbidities such as chronic obstructive pulmonary disease, cancer, congestive heart failure, and interstitial lung disease can impact the patient's hemodynamic ability to tolerate submassive PE. In this review, we address the definitions, risk stratification (clinical, laboratory, and imaging), management approaches, and long-term outcomes of submassive PE. We also discuss the role of the PE response team in management of patients with PE.

Update on Thrombolytic Therapy in Acute Pulmonary Thromboembolism

Thrombolytic treatment accelerates the dissolution of thrombus in acute pulmonary thromboembolism (PTE) and is potentially a lifesaving treatment. High-risk PTE is the clearest indication for this therapy, and its use in intermediate-risk cases is still controversial. A PTE response team may enable a rapid and effective determination of risk and treatment in these controversial clinical cases. Approved thrombolytic agents for the PTE treatment are streptokinase, urokinase, and alteplase. Currently, the most widely used agent is alteplase. It has a short infusion time (2 h) and a rapid effect. Newer, unapproved agents for the PTE treatment are tenecteplase and reteplase. The active resolution of thrombus via thrombolytic agents improves rapidly pulmonary perfusion, hemodynamic defect, gas exchange, and right ventricular dysfunction. However, it is important to determine appropriate candidates carefully, to prevent hemorrhage, which is the most important side effect of these drugs. Catheter-directed thrombolysis seems to be an alternative in patients not eligible for systemic thrombolytic therapy.

Temporal trends in management and outcome of pulmonary embolism: a single-centre experience

Background

Real-world data on the impact of advances in risk-adjusted management on the outcome of patients with pulmonary embolism (PE) are limited.

Methods

To investigate temporal trends in treatment, in-hospital adverse outcomes and 1-year mortality, we analysed data from 605 patients [median age, 70 years (IQR 56–77) years, 53% female] consecutively enrolled in a single-centre registry between 09/2008 and 08/2016.

Results

Over the 8-year period, more patients were classified to lower risk classes according to the European Society of Cardiology (ESC) 2014 guideline algorithm while the number of high-risk patients with out-of-hospital cardiac arrest (OHCA) increased. Although patients with OHCA had an exceptionally high in-hospital mortality rate of 59.3%, the rate of PE-related in-hospital adverse outcomes (12.2%) in the overall patient cohort remained stable over time. The rate of reperfusion treatment was 9.6% and tended to increase in high-risk patients. We observed a decrease in the median duration of in-hospital stay from 10 (IQR 6–14) to 7 (IQR 4–15) days, an increase of patients discharged early from 2.1 to 12.2% and an increase in the use of non-vitamin K-dependent oral anticoagulants (NOACs) from 12.6 to 57.2% in the last 2 years (09/2014–08/2016) compared to first 6 years (09/2008–08/2014). The 1-year mortality rate (16.9%) remained stable throughout the study period.

Conclusion

In-hospital adverse outcomes and 1-year mortality remained stable despite more patients with OHCA, shorter in-hospital stays, more patients discharged early and a more frequent NOAC use.

Electronic supplementary material

The online version of this article (10.1007/s00392-019-01489-9) contains supplementary material, which is available to authorized users.

Ultrasound-assisted versus conventional catheter-directed thrombolysis for acute pulmonary embolism: A multicenter comparison of patient-centered outcomes

Both catheter-directed thrombolysis (CDT) and ultrasound-assisted thrombolysis (USAT) are novel treatment modalities for patients presenting with acute pulmonary embolism (PE). The objective of this study was to compare clinical and quality-of-life (QOL) outcomes for patients undergoing either treatment modality. We retrospectively studied 70 consecutive patients treated with either CDT or USAT over 3 years at a multicenter health system. The primary clinical efficacy endpoint was right ventricular systolic pressure (RVSP) reduction post-procedurally. Safety endpoints were mortality and bleeding incidents based on Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries (GUSTO) criteria. Long-term QOL was assessed using the 36-Item Short-Form Health Survey (SF-36) via phone interview. Thirty-seven patients (53%) in our study underwent USAT and 33 (47%) patients were treated with conventional CDT. Among all patients studied, 96% had echocardiographic evidence for right ventricular strain on admission. Mean RVSP decreased by 18 ± 13 mmHg in the USAT group post-procedurally as compared to 14 ± 16 mmHg in the CDT group, without significant difference between groups ( p = 0.31). Rates of moderate and severe bleeding were largely identical between USAT and CDT groups (USAT: 3%; CDT: 0%; p = 0.09). There was no death in either group during admission. At long-term follow-up, there was no significant difference in QOL between both treatment modalities in all eight functional domains of SF-36. Our retrospective study demonstrated using USAT over conventional CDT for acute submassive or massive PE did not yield additional clinical, safety, or long-term QOL benefit.

Predictors of failure and complications of catheter-directed interventions for pulmonary embolism

OBJECTIVE

Catheter-directed interventions (CDIs) are increasingly performed for acute pulmonary embolism (PE) as they are presumed to provide similar therapeutic benefits to systemic thrombolysis while decreasing the dose of thrombolytic required and the associated risks. This study aimed to identify factors associated with CDI failure and to describe anticipated complications.

METHODS

Consecutive patients who underwent CDI for massive or submassive PE between 2009 and 2015 were identified; outcomes and complications were retrospectively collected. CDI clinical failure was defined as major bleeding, perioperative stroke or other major adverse procedure-related event, decompensation for submassive or persistent shock for massive PE, need for surgical thromboembolectomy, or in-hospital death. Univariate analysis was used to study the factors associated with CDI failure.

RESULTS

There were 102 patients who received a CDI during the study period (36 standard catheter thrombolysis, 60 ultrasound assisted, 6 other; age, 59.2 ± 15.9 years; male, 50 [49.0%]; massive PE, 14 [13.7%]). Five patients (4.9%) had a major contraindication and 15 patients (14.7%) had a minor contraindication to systemic thrombolysis. The mean alteplase dose was 28.2 ± 18.8 mg (range, 0-123 mg; three patients had already received systemic lysis). CDI failure occurred in 15 patients (14.7%; 7 in massive PE, 8 in submassive PE). Of these patients, seven had major bleeding events, whereas eight patients decompensated. Ten (9.8%) patients had minor bleeding events (four access related). Factors associated with CDI failure and major bleeding included massive PE, age ≥70 years, and major contraindication to thrombolytics. Both failures and bleeding events were independent of lysis dose and CDI technique.

CONCLUSIONS

CDIs for acute PE are not risk-free procedures, and their use should be individualized on the basis of a risk-benefit ratio. Particularly for patients with major contraindications to systemic thrombolytics, CDIs should be used selectively. Lytic dose, within the low-volume range administered in CDI, and type of CDI seem to have no impact on adverse events.

Catheter-directed interventions compared with systemic thrombolysis achieve improved ventricular function recovery at a potentially lower complication rate for acute pulmonary embolism

OBJECTIVE

Catheter-directed interventions (CDIs) are increasingly performed for acute pulmonary embolism (PE) as they are presumed to provide similar therapeutic benefits to systemic thrombolysis (ST) while decreasing the associated complications. The purpose of this study was to compare outcomes between CDI and ST.

METHODS

Consecutive patients who underwent CDIs or ST for massive or submassive PE between 2006 and 2016 were identified. Clinical and echocardiographic parameters at baseline and after treatment were recorded. Clinical success was defined as decompensation resolution (or prevention) without major bleeding, stroke, other major treatment-related event, or in-hospital death. The χ² test and t-test were used for between-groups comparisons.

RESULTS

There were 213 patients who received CDIs (standard catheter thrombolysis in 56, ultrasound-assisted thrombolysis in 146, suction thrombectomies in 10, and pharmacomechanical thrombolysis in 1) and 104 patients who received ST (94 high dose [100 mg], 10 low dose [50 mg]). At baseline, CDI and ST groups had comparable echocardiographic parameters, demographics, and comorbidities, except for PE type (massive PE, 8.5% for CDIs vs 69.2% for ST; P < .001), age (60.2 ± 14.9 years for CDIs vs 55.9 ± 17.3 years for ST; P = .023), and renal function (glomerular filtration rate, 78.1 ± 33.7 mL/min/1.73 m² for CDIs vs 64.1 ± 35.2 mL/min/1.73 m² for ST; P = .001). Without stratifying per PE type, CDIs had a higher clinical success rate (87.8% vs 66.3%; P < .001) and a lower rate of major bleed (8.0% vs 19.2%; P = .003), stroke (1.4% vs 4.8%; P = .120), and death (1.4% vs 13.5%; P < .001). On stratifying by PE type, there was no difference in clinical success between groups. The mean reduction in right ventricular/left ventricular diameter ratio between baseline and the first post-treatment echocardiographic examination (within 30 days) was significantly higher for CDI (0.27 ± 0.20 vs 0.18 ± 0.15; P = .037). Beyond 30 days, there was no echocardiographic difference between groups. There was no significant difference in clinical outcomes and echocardiographic parameters between standard and ultrasound-assisted CDIs.

CONCLUSIONS

CDIs provide improved recovery of right ventricular function compared with ST. Major bleeding and stroke complications may be lower, but larger studies are needed to validate this. CDIs are complementary to ST, and their use should be individualized on the basis of the patients' clinical presentation, risk profile, and local resources.

Fixed low-dose ultrasound-assisted catheter-directed thrombolysis followed by routine stenting of residual stenosis for acute ilio-femoral deep-vein thrombosis

Patients with ilio-femoral deep-vein thrombosis (DVT) are at high risk of developing the postthrombotic syndrome (PTS). In comparison to anticoagulation therapy alone, extended venography-guided catheter-directed thrombolysis without routine stenting of venous stenosis in patients with ilio-femoral DVT is associated with an increased risk of bleeding and a moderate reduction of PTS. We performed a prospective single-centre study to investigate safety, patency and incidence of PTS in patients with acute iliofemoral DVT treated with fixed-dose ultrasound-assisted catheter-directed thrombolysis (USAT; 20 mg rt-PA during 15 hours) followed by routing stenting of venous stenosis, defined as residual luminal narrowing >50%, absent antegrade flow, or presence of collateral flow at the site of suspected stenosis. A total of 87 patients (age 46 ± 21 years, 60% women) were included. At 15 hours, thrombolysis success ≥50% was achieved in 67 (77%) patients. Venous stenting (mean 1.9 ± 1.3 stents) was performed in 70 (80%) patients, with the common iliac vein as the most frequent stenting site (83%). One major (1%; 95% CI, 0–6%) and 6 minor bleedings (7%; 95%CI, 3–14%) occurred. Primary and secondary patency rates at 1 year were 87% (95% CI, 74–94%) and 96% (95% CI, 88–99%), respectively. At three months, 88% (95% CI, 78–94%) of patients were free from PTS according to the Villalta scale, with a similar rate at one year (94%, 95% CI, 81–99%). In conclusion, a fixed-dose USAT regimen followed by routine stenting of underlying venous stenosis in patients with iliofemoral DVT was associated with a low bleeding rate, high patency rates, and a low incidence of PTS.

Catheter-directed therapy as a treatment for submassive pulmonary embolism: A meta-analysis

AIMS

Catheter-directed therapy (CDT) is included in the guidelines for diagnosing and treating massive pulmonary embolism. However, few studies have evaluated the efficacy of CDT as a treatment for submassive pulmonary embolism (SPE). Therefore, we used evidence-based medicine to evaluate the effectiveness and safety of CDT in treating SPE.

METHODS

Search terms describing CDT in SPE and patients with intermediate pulmonary embolism were entered into the PubMed, Embase and Cochrane Library databases to identify relevant articles without language restrictions published between January 1990 and December 2016. A quality assessment and data extraction were performed by two investigators. The clinical efficacy of and major complications associated with treatment were analysed using a fixed effects model.

KEY FINDINGS

A total of 552 patients in 16 studies were included in this meta-analysis. The clinical success rate in CDT was approximately 100% (95% confidence interval (CI): 99%, 100%), the primary bleeding rate was 0.02% (95% CI: 0%, 0.05%), and mortality during hospitalization was approximately 0% (95% CI: 0%, 0.01%). The mean decrease in pulmonary artery systolic pressure after treatment was -14.9% (95% CI: -19.25%, -10.55%), and the mean post-treatment change in the ratio of the right to the left ventricle (RV/LV) was -0.35% (95% CI: -0.48%, -0.22%).

SIGNIFICANCE

CDT is effective and safe as a treatment for SPE and could be a first-line treatment for SPE under specific conditions.

Comparison of Ultrasound-Accelerated versus Pigtail Catheter-Directed Thrombolysis for the Treatment of Acute Massive and Submassive Pulmonary Embolism

PURPOSE

To compare the technical and clinical effectiveness of ultrasound-accelerated endovascular thrombolysis (USAT) versus pigtail catheter-directed thrombolysis (PCDT) for the treatment of acute pulmonary embolism (PE).

MATERIALS AND METHODS

A single-center retrospective study of patients treated with USAT or PCDT for acute massive or submassive PE between January 2010 and December 2016 was performed by reviewing electronic medical records. Sixty treatments were reviewed (mean patient age, 56.7 y ± 14.6), including 52 cases of submassive PE (21 treated with USAT, 31 with PCDT) and 8 cases of massive PE (3 treated with USAT, 5 with PCDT). Endpoints included pulmonary artery pressure (PAP), Miller PE severity index, tissue plasminogen activator (TPA) dose, infusion duration, procedural variables, and complications.

RESULTS

Demographics, PE severity, and right:left ventricular diameter ratios were similar between groups. USAT and PCDT significantly reduced mean PAP (reductions of 7.4 mm Hg [P = .002] and 8.2 mm Hg [P < .001], respectively) and Miller index scores (reductions of 45.8% [P < .001] and 53% [P < .001], respectively) with similar effectiveness (P = .47 and P = .15, respectively). Procedure (P < .001) and fluoroscopy (P = .001) times were significantly longer in the USAT group. The USAT group underwent fewer sessions (2.2 ± 0.6 vs 2.4 ± 0.6; P = .17) with shorter infusion times (23.9 h ± 8.8 vs 30.4 h ± 12.6; P = .065) and a lower total dose of TPA (27.1 mg ± 11.3 vs 30.4 mg ± 12.6; P = .075) compared with the PCDT group, but the differences were not significant. Complications (P = .07) and 30-day mortality rates (P = .56) were not significantly different between groups.

CONCLUSIONS

USAT and PCDT demonstrated comparable effectiveness and safety in the treatment of patients with acute PE.

Ultrasound Assisted Catheter-Directed Thrombolysis of Acute Pulmonary Embolism: A Review of Current Literature

Pulmonary embolism continues as a very common and also presumably life-threatening disorder. For affected individuals with intermediate- as well as high-risk pulmonary embolism, catheter-based revascularization procedures have developed a possible substitute for systemic thrombolysis or for surgical embolectomy. Ultrasound-assisted catheter-directed thrombolysis is an innovative catheter-based approach; which is the main purpose of the present review article. Ultrasound-assisted catheter-directed thrombolysis is much more efficacious in reversing right ventricular dysfunction as well as dilatation in comparison to anticoagulation alone in individuals at intermediate risk. However, a direct comparison of ultrasound-assisted thrombolysis with systemic thrombolysis or surgical thrombectomy is not available. Ultrasound-assisted thrombolysis with early intrapulmonary thrombolytic bolus could also be successful in high-risk patients, but unfortunately, data from randomized trials is limited. This review article recapitulates existing information on ultrasound-assisted thrombolysis for acute pulmonary embolism.

Safety of catheter-directed thrombolysis for massive and submassive pulmonary embolism: Results of a multicenter registry and meta-analysis

OBJECTIVES

To evaluate the safety and efficacy of catheter-directed thrombolysis (CDT) in the treatment of acute pulmonary embolism (PE).

BACKGROUND

The use of CDT for the treatment of acute submassive and massive PE is increasing in frequency. However, its safety and efficacy have not been well elucidated.

METHODS

This study is made of two parts: one is a two-center registry of acute PE patients treated with CDT. The safety outcome evaluated was any major complication including fatal, intracranial (ICH), intraocular, or retroperitoneal hemorrhage or any overt bleeding requiring transfusion or surgical repair. The efficacy outcome was acute change in invasive pulmonary artery systolic pressure (PASP). The second part is a meta-analysis of all contemporary studies that used CDT for PE. Reported outcomes are the same as in the registry, with the addition of right ventricular to left ventricular (RV/LV) ratio change.

RESULTS

In the registry, 137 patients were included (age 59 ± 15, 50% male, 88% submassive PE). ICH occurred in two patients and major complications in 13 (9.4%). PASP decreased post procedure by 19 ± 15 mm Hg (95% CI 16-23). In the meta-analysis, 16 studies were included with 860 patients. Rate of ICH was 0.35% and the major complication rate was 4.65%, most requiring transfusion only. In-hospital mortality was 12.9% in the massive and 0.74% in the submassive group. All studies showed improvement in PASP and/or RV/LV ratio post CDT.

CONCLUSIONS

CDT is associated with a low major complication rate. Randomized studies are needed to evaluate its efficacy relative to anticoagulation alone. © 2017 Wiley Periodicals, Inc.