Ultrasound-Assisted Versus Standard Catheter-Directed Thrombolysis for Acute Pulmonary Embolism: Insights From National Inpatient Sample

Background

Pulmonary embolism is one of the leading causes of morbidity and mortality in the United States. Catheter-directed therapies have emerged as a promising treatment for managing intermediate- and high-risk patients; however, data comparing standard catheter-directed thrombolysis (SCDT) and ultrasound-assisted thrombolysis (USAT) are limited. This study aimed to investigate trends, outcomes, and predictors of mortality of both modalities from a nationally representative sample.

Methods

This analysis used data from the National Inpatient Sample years 2016-2020. The primary outcome was in-hospital mortality. A multivariable regression model was used to compare the outcomes.

Results

Among 39,430 patients who received catheter-directed thrombolysis, 26,710 (76.8%) received SCDT and 8060 (23.2%) received USAT. The utilization of SCDT and USAT increased during the study years except for 2020. In-hospital mortality was lower among patients who received USAT (2.7% vs 3.8%; P = .04) compared with patients who received SCDT in the unadjusted analysis. On multivariable regression analysis, there was no difference in the incidence of in-hospital mortality between USAT and SCDT (odds ratio, 0.75; 95% CI, 0.52-1.08; P = .13). There were no significant differences between SCDT and USAT groups in the rate of bleeding adverse events including intracranial hemorrhage (0.6% vs 0.4%; P = .47), and nonintracranial major bleeding (4.2% vs 4.1%; P = .72).

Conclusions

Ultrasound-assisted thrombolysis was associated with similar in-hospital mortality and bleeding complications compared with SCDT for acute pulmonary embolism. Further studies are warranted to confirm evaluate the long-term outcomes with both modalities.

Ultrasound-Facilitated, Catheter-Directed Thrombolysis for Acute Pulmonary Embolism

BACKGROUND

Acute pulmonary embolism (APE) poses a significant risk to patient health, with treatment options varying in efficacy and safety. Ultrasound-facilitated catheter-directed thrombolysis (USCDT) has emerged as a potential alternative to conventional catheter-directed thrombolysis (CDT) for patients with intermediate to high-risk APE. This study aimed to compare the efficacy and safety of USCDT versus conventional CDT in patients with intermediate to high-risk APE.

METHODS

This observational retrospective study was conducted at the Armed Forces Hospital, Al-Hada, Taif, the Kingdom of Saudi Arabia (KSA), on 135 patients diagnosed with APE and treated with either USCDT or CDT (58 underwent CDT, while 77 underwent USCDT). The primary efficacy outcome was the change in the right ventricle to the left ventricle (RV/LV) diameter ratio. Secondary outcomes included changes in pulmonary artery systolic pressure and the Miller angiographic obstruction index score. Safety outcomes focused on major bleeding events.

RESULTS

Both USCDT and CDT significantly reduced RV/LV diameter ratio (from 1.35 ± 0.14 to 1.05 ± 0.17, P < 0.001) and systolic pulmonary artery pressure (SPAP) (from 55 ± 7 mmHg to 38 ± 7 mmHg, P < 0.001) at 48- and 12-hours post-procedure, respectively, with no significant differences between treatments. However, USCDT was associated with a significantly lower rate of major bleeding events compared to CDT (0% vs. 3.4%, P = 0.008). Multivariate logistic regression analysis revealed that USCDT was associated with a 71.9% risk reduction of bleeding (OR = 0.281, 95% CI = 0.126 - 0.627, P = 0.002).

CONCLUSIONS

USCDT is a safe and effective alternative to CDT for the treatment of intermediate to high-risk APE, as it significantly reduces the risk of major bleeding.

Comparison of important factors to patients recovering from pulmonary embolism and items covered in patient-reported outcome measures: A mixed-methods systematic review

OBJECTIVE

Up to 50 % of patients recovering from pulmonary embolism (PE) experience negative long-term outcomes. Patient-reported outcome measures (PROMs) are important in identifying what matters to patients. We aimed to identify PROMs used in clinical studies and recommended by the International Consortium of Health Outcomes (ICHOM) and compare individual items with factors considered important by patients recovering from PE.

METHODS

This was a convergent mixed-methods systematic review, including quantitative studies, using PROMs and qualitative studies with non-cancer-related PE patients. Items from each PROM and qualitative findings were categorised using an International Classification of Function linking process to allow for integrated synthesis.

RESULTS

A total of 68 studies using 34 different PROMs with 657 items and 13 qualitative studies with 408 findings were included. A total of 104 individual ICF codes were used, and subsequently sorted into 20 distinct categories representing patient concerns. Identified PROMs were found to adequately cover 17/20 categories, including anxiety, fear of bleeding, stress, depression, dizziness/nausea, sleep disturbance, pain, dyspnea, fatigue, activity levels, family and friends, socializing, outlook on life, and medical treatment. PROMs from the ICHOM core set covered the same categories, except for dizziness/nausea.

CONCLUSIONS

No single PROM covered all aspects assessed as important by the PE population. PROMs recommended in the ICHOM core set cover 16/20 aspects. However, worrisome thoughts, hypervigilance around symptoms, and uncertainty of illness were experienced by patients with PE but were not covered by PROMS.

Patient-Reported Outcomes in Venous Thromboembolism: A Systematic Review of the Literature, Current Challenges, and Ways Forward

BACKGROUND

Venous thromboembolism (VTE) affects >1.2 million Americans annually. Although the clinical outcomes and economic burdens of VTE have been well described, the impact of VTE on patients' health status has yet to be summarized. This systematic review summarizes how patient-reported outcome measures (PROMs) have been used in VTE to date.

METHODS AND RESULTS

PubMed/MEDLINE was queried for literature published through March 2023 using PROMs in a population of patients with VTE. Studies were excluded if the reference was an editorial, review, or case report, or if the study included patients with conditions other than VTE. Qualitative analyses were performed. After screening and exclusion, 136 references were identified; 5 described PROM development, 20 focused on PROM validation, and 111 used PROMs in outcomes research. The most used generic PROMs were the 36-item Short-Form Health Survey and EuroQol 5-dimensional questionnaire, and the most common disease-specific PROMs were the Venous Insufficiency Epidemiological and Economic Study-Quality of Life/Symptoms and the Pulmonary Embolism Quality of Life Questionnaire. PROMs were used to quantify the changes in health status after diagnosis, characterize the trajectory of subsequent improvement, and identify drivers of continued impairments in health status like postthrombotic syndrome and postpulmonary embolism syndrome. PROMs were also used to investigate the impact of novel treatment modalities on quality of life.

CONCLUSIONS

This review demonstrates the many benefits of PROM use, including quantifying changes in health status with treatment, capturing patients' experiences with the treatment itself, and identifying complications of VTE. Incorporating PROMs into VTE care will be an essential component of evaluating the effectiveness of novel therapies and should lead to improved shared decision-making for patients with VTE.

Comparison of outcomes and complications in conventional versus ultrasound-accelerated catheter directed thrombolysis for treatment of pulmonary embolism: A systematic review and meta-analysis

BACKGROUND

Acute submassive a massive pulmonary embolism are known as leading causes of cardiovascular morbidity and mortality in emergency departments. Choosing the optimal type of catheter directed thrombolysis (CDT) for treatment of pulmonary embolism presents a quandary to the practitioners. To the best of our knowledge, there is no meta-analysis comparing superiority of conventional CDT and ultrasound-accelerated catheter directed thrombolysis (USACDT). Therefore, in this meta-analysis, we aimed to compare conventional CDT with USACDT regarding clinical outcomes and safety profile.

METHODS

A systematic literature search of previous published studies comparing conventional CDT with USACDT regarding clinical outcomes and safety profile was carried out in the electronic databases including MEDLINE, Scopus, EBSCO, Google Scholar, Web of Science, and Cochrane from inception to December 2021. Data were analyzed by comprehensive meta-analysis software (CMA, version 3).

RESULTS

The meta-analysis included nine studies with a total of 705 patients. Our meta-analysis showed that there is no significant difference between two groups with respect to pulmonary arterial systolic pressure (SMD: -0.084; 95% CI: -0.287 to 0.12; p: 0.41), RV/LV (SMD: -0.003; 95% CI: -0.277 to 0.270; p: 0.98), and Miller score (SMD: -0.345; 95% CI: -1.376 to 0.686; p: 0.51). Similarly, we found no statistically significant differences between two groups regarding major and minor bleeding (p > .05).

CONCLUSION

Our meta-analysis showed that when compared with USACDT, conventional CDT provides similar clinical and hemodynamic outcomes or safety for treatment of pulmonary embolism without the need for very expensive technologies. However, randomized clinical trials are required to further investigate cost-effectiveness of USACDT in comparison with conventional CDT.

Catheter-Directed Thrombolysis or Catheter-Based Thrombectomy in Acute Pulmonary Embolism: Horses for Courses

Venous thromboembolism is a common disorder encompassing both pulmonary embolism (PE) and deep vein thrombosis (DVT). In the United States, up to 2 million people are diagnosed with DVT and 600,000 with PE annually. The purpose of this review is to discuss the indications and evidence for catheter-directed thrombolysis versus catheter-based thrombectomy.

Clinical Observation of Uninterrupted Thrombolytic Therapy via Indwelling Catheter for Lower Limb Deep Vein Thrombosis

Purpose

Observe uninterrupted thrombolytic therapy via indwelling catheter for lower limb deep vein thrombosis.

Methods

We retrospectively studied data from 32 patients with lower extremity deep vein thrombosis who received comprehensive treatment, consisting of general treatment, inferior vena cava filter implantation, interventional thrombolysis, angioplasty, stenting, and post-operative monitoring.

Results

The efficacy and safety of the comprehensive treatment were observed for a follow-up period of 6-12 months. The treatment was 100% effective; patient results indicated no serious bleeding, acute pulmonary embolism, or death after surgery.

Conclusion

The combination of intravenous and healthy side femoral vein puncture and directed thrombolysis to treat acute lower limb deep vein thrombosis is safe, effective, and minimally invasive while still achieving a good therapeutic effect.

Percutaneous Management of High-Risk Pulmonary Embolism

Acute pulmonary embolism (PE) leads to an abrupt increase in pulmonary vascular resistance and right ventricular afterload, and when significant enough, can result in hemodynamic instability. High-risk PE is a dire cardiovascular emergency and portends a poor prognosis. Traditional therapeutic options to rapidly reduce thrombus burden like systemic thrombolysis and surgical pulmonary endarterectomy have limitations, both with regards to appropriate candidates and efficacy, and have limited data demonstrating their benefit in high-risk PE. There are growing percutaneous treatment options for acute PE that include both localized thrombolysis and mechanical embolectomy. Data for such therapies with high-risk PE are currently limited. However, given the limitations, there is an opportunity to improve outcomes, with percutaneous treatments options offering new mechanisms for clot reduction with a possible improved safety profile compared with systemic thrombolysis. Additionally, mechanical circulatory support options allow for complementary treatment for patients with persistent instability, allowing for a bridge to more definitive treatment options. As more data develop, a shift toward a percutaneous approach with mechanical circulatory support may become a preferred option for the management of high-risk PE at tertiary care centers.

A Meta-analysis of Standard Versus Ultrasound-Assisted Catheter-Directed Thrombolysis in the Management of Acute Pulmonary Embolism

Background

Standard catheter-directed thrombolysis (SCDT) harnesses the therapeutic benefit of systemic thrombolytics while minimizing bleeding complications in patients presenting with pulmonary embolism (PE). Ultrasound-assisted catheter-directed thrombolysis (USAT) theoretically improves upon SCDT by disrupting fibrin and increasing the surface area exposed to thrombolytic agent. However, it is unclear if this translates into improved outcomes.

Methods

A systematic search of prior publications comparing SCDT and USAT in patients with intermediate or high-risk PE was conducted. Primary outcomes of interest were bleeding events, ICU and hospital length of stay. Secondary outcomes included changes in pulmonary artery systolic pressure (PASP), mean pulmonary artery pressure (mPAP), and right ventricle to left ventricle diameter (RV/LV) ratio. Studies that lacked comparison groups were excluded. Bias assessments were performed using the Cochrane tools for randomized and nonrandomized studies. Data was collated utilizing the Cochrane Review Manager software, and all analyses assumed random effects.

Results

Our search yielded 7 observational studies and 1 randomized control trial. The studies included a total of 543 patients who underwent either SCDT (n = 273) or USAT (n = 270) for intermediate or high-risk PE. The synthesized analysis showed no significant differences in bleeding between the groups. There were no differences in ICU or hospital lengths of stay, changes in PASP, or mPAP. Reductions in RV/LV ratio were greater with SCDT (mean difference, -0.16; 95% CI, -0.27 to -0.06; P = .003).

Conclusions

In comparison to SCDT, USAT did not result in improved clinical or hemodynamic outcomes in patients presenting with PE. Results were limited by heterogeneity among the included studies.

Systemic thrombolytic and ultrasound-assisted catheter-directed thrombolysis for treatment of acute pulmonary embolism: a 7-year, multicenter experience

Treatment of acute pulmonary embolism (PE) varies based upon risk stratification and ranges from outpatient oral anticoagulation to emergency surgical embolectomy. Patients with high-risk PE can be considered for systemic thrombolytic (ST) based upon guideline recommendations, but intermediate-risk PE does not currently have strong evidence to guide primary reperfusion strategies via thrombolytic administration. Ultrasound-assisted catheter-directed thrombolysis (USAT) is an alternative reperfusion option to ST but is not currently recommended as first line in any key guidelines due to limited available evidence. This retrospective, multicenter, observational study compares 210 patients treated with USAT (n = 105) or ST (n = 105) for acute high- or intermediate-risk PE in three hospitals. Baseline characteristics were significant in that severity of illness was higher in those that received ST, which limited comparisons of outcomes. The primary outcome of major bleeding in patients receiving USAT was 15.2% and 22.9% in those that received ST. Efficacy of reperfusion strategy was observed to be 86.7% of patients in USAT group and 65.7% in ST group. Reperfusion strategies had no difference in in-hospital death, intensive care length of stay, or hospital length of stay. Predefined subgroup analysis found that high-risk PE had higher mortality (14.7%) than intermediate-risk PE (0%) regardless of reperfusion strategy. Upon multivariate analysis, high-risk PE was the only independent risk factor for major bleeding while USAT therapy and intermediate-risk PE were independent predictors of efficacy. Due to the difference in baseline severity of illness, direct comparisons in primary outcomes to each group was not performed. We have described real world usage of both USAT and ST and which patients were likely to receive each therapy at these institutions.

Clinical efficacy and safety of ultrasound-assisted thrombolysis vs. standard catheter-directed thrombolysis in patients with acute pulmonary embolism: A study level meta-analysis of clinical trials

Aim

To compare the clinical efficacy of ultrasound-assisted thrombolysis (USAT) vs. standard catheter-directed thrombolysis (SCDT) in patients with acute pulmonary embolism (aPE).

Methods

This study analyzed the clinical outcomes of patients with non-low-risk aPE who received USAT or SCDT. The primary outcomes were all-cause death, total bleeding, and major bleeding. Secondary outcomes included pulmonary thrombotic load score (Miller), improvement in right ventricular-to-left ventricular ratio (RV/LV), dose and duration of the thrombolytic drug tissue plasminogen activator (tPA), length of stay (LOS) in the ICU, and total LOS in the hospital.

Results

A total of seven articles and 451 patients were included in this study. 241 patients were in the USAT group and 210 patients were in the SCDT group. There were no significant differences in all-cause mortality, total bleeding, and major bleeding between the two groups. Miller scores for pulmonary thrombus also showed no difference between the two groups, but pulmonary artery systolic pressure (PASP) was lower in the SCDT group after-treatment. The reduction of RV/LV from baseline was more pronounced in the SCDT group than in the USAT group (OR: -0.14, 95%CI: -0.20 to 0.07, P < 0.0001, I ² = 0%). Total dose of tPA and duration of infusion in the USAT group were lower than those in the SCDT group, but there was no significant statistical difference. LOS in the ICU was similar between the two groups, while LOS in the hospital was lower in the SCDT group.

Conclusion

This study did not detect any differences in all-cause mortality, total bleeding, and major bleeding between non-low-risk aPE patients treated with USAT or SCDT. Improvement in right ventricular function was better in the SCDT group, and hospital LOS was lower in the SCDT group.

Contemporary Management of Acute Pulmonary Embolism: Evolution of Catheter-based Therapy

Acute pulmonary embolism (PE) affects more than 100 000 people in the United States annually and is the third leading cardiovascular cause of death. The standard management for PE is systemic anticoagulation therapy. However, a subset of patients experience hemodynamic decompensation, despite conservative measures. Traditionally, these patients have been treated with systemic administration of thrombolytic agents or open cardiac surgery, although attempts at endovascular treatment have a long history that dates back to the 1960s. The technology for catheter-based therapy for acute PE is rapidly evolving, with multiple devices approved over the past decade. Currently available devices fall into two broad categories of treatment methods: catheter-directed thrombolysis and percutaneous suction thrombectomy. Catheter-directed thrombolysis is the infusion of thrombolytic agents directly into the occluded pulmonary arteries to increase local delivery and decrease the total dose. Suction thrombectomy involves the use of small- or large-bore catheters to mechanically aspirate a clot from the pulmonary arteries without the need for a thrombolytic agent. A thorough understanding of the various risk stratification schemes and the available evidence for each device is critical for optimal treatment of this complex entity. Multiple ongoing studies will improve our understanding of the role of catheter-based therapy for acute PE in the next 5-10 years. A multidisciplinary approach through PE response teams has become the management standard at most institutions. An invited commentary by Bulman and Weinstein is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Current trends in image-guided chest interventions

Interventional radiology (IR) is a rapidly expanding medical subspecialty and refers to a range of image‐guided procedural techniques. The image guidance allows real‐time visualization and precision placement of a needle, catheter, wire and device to deep body structures through small incisions. Advantages include reduced risks, faster recovery and shorter hospital stays, lower costs and less patient discomfort. The range of chest interventional procedures keeps on expanding due to improved imaging facilities, better percutaneous assess devices and advancing ablation and embolization techniques. These advances permit procedures to be undertaken safely, simultaneously and effectively, hence escalating the role of IR in the treatment of chest disorders. This review article aims to cover the latest developments in some image‐guided techniques of the chest, including thermal ablation therapy of lung malignancy, targeted therapy of pulmonary embolism, angioplasty and stenting of mediastinal venous/superior vena cava occlusion, pulmonary arteriovenous malformation treatment and bronchial artery embolization for haemoptysis.

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-Based Therapies Decrease Mortality in Patients With Intermediate and High-Risk Pulmonary Embolism: Evidence From Meta-Analysis of 65,589 Patients

Background

Catheter-directed therapies (CDT) are an alternative to systemic thrombolysis (ST) in pulmonary embolism (PE) patients, but the mortality benefit of CDT is unclear.

Objective

We conducted a systematic review with meta-analysis to compare the efficacy and safety of CDT and ST in intermediate-high and high-risk PE.

Methods

We included (P) participants, adult PE patients; (I) intervention, CDT; (C) comparison, ST; (O) outcomes, mortality, complications, in-hospital treatment, and length of hospital stay; (S) study design, randomized controlled trials (RCTs), or cohort comparing CDT and ST. The primary endpoint was 30-day mortality. Secondary outcomes included treatment-related complications including bleeding, the use of hospital resources, and length of hospital stay.

Results

Eleven studies including 65,589 patients met the inclusion criteria. Thirty-day mortality was lower in the CDT group, compared to ST group [7.3 vs. 13.6%; odds ratio (OR) = 0.51, 95% confidence interval (CI) 0.38–0.69, p < 0.001]. The rates of myocardial injury, cardiac arrest, and stroke were lower in CDT group, compared to ST group (p < 0.001 for all). The rates of any major bleeding, intracranial hemorrhage, hemoptysis, and red blood cell transfusion were lower in patients treated with CDT, compared to ST (p ≤ 0.01 for all). Extracorporeal life support was used more often in patients treated with CDT, compared to ST (0.5 vs. 0.2%, OR = 2.52, 95% CI 1.88–3.39, p < 0.001). The use of hospital resources and length of hospital stay were comparable in both groups.

Conclusion

CDT might decrease mortality in patients with intermediate-high and high-risk PE and were associated with fewer complications, including major bleeding.

Ultrasound-accelerated thrombolysis in high-risk perioperative pulmonary embolism: two case reports and review of literature

Introduction

Treatment of high-risk pulmonary embolism (PE) in perioperative patients remains challenging. Systemic thrombolysis is associated with a high risk of major bleedings and intracranial haemorrhage. High mortality rates are reported for open pulmonary embolectomy. Therefore, postoperative surgical patients may benefit substantially from catheter-directed ultrasound-accelerated thrombolysis (USAT).

Case presentation

We report two cases of high-risk perioperative PE. Both patients developed severe haemodynamic instability leading to cardiac arrest. After the implantation of a veno-arterial extracorporeal membrane oxygenation (ECMO), they were both successfully treated with USAT. Adequate improvement of right ventricular function was achieved; thus, ECMO could be successfully weaned after 3 and 4 days, respectively. Both patients showed favourable outcomes and could be discharged to rehabilitation.

Conclusion

Current guidelines on treatment of PE offer no specific therapies for perioperative patients with high-risk PE. However, systemic thrombolysis is often excluded due to the perioperative setting and the risk of major bleeding. Catheter-directed thrombolysis was shown to utilise less thrombolytic agent while obtaining comparable thrombolytic effects. The risk for major bleeding (including intracranial haemorrhage) is also significantly lowered. Until further trials determining the value of adopted treatment strategies of high-risk PE in perioperative patients are available, USAT should be considered in similar cases.

Randomized Trial Comparing Standard Versus Ultrasound-Assisted Thrombolysis for Submassive Pulmonary Embolism: The SUNSET sPE Trial

OBJECTIVES

The aim of this trial was to determine whether ultrasound-assisted thrombolysis (USAT) is superior to standard catheter-directed thrombolysis (SCDT) in pulmonary arterial thrombus reduction for patients with submassive pulmonary embolism (sPE).

BACKGROUND

Catheter-directed therapy has been increasingly used in sPE and massive pulmonary embolism as a decompensation prevention and potentially lifesaving procedure. It is unproved whether USAT is superior to SCDT using traditional multiple-side-hole catheters in the treatment of patients with pulmonary embolism.

METHODS

Adults with sPE were enrolled. Participants were randomized 1:1 to USAT or SCDT. The primary outcome was 48-hour clearance of pulmonary thrombus assessed by pre- and postprocedural computed tomographic angiography using a refined Miller score. Secondary outcomes included improvement in right ventricular-to-left ventricular ratio, intensive care unit and hospital stay, bleeding, and adverse events up to 90 days.

RESULTS

Eighty-one patients with acute sPE were randomized and were available for analysis. The mean total dose of alteplase for USAT was 19 ± 7 mg and for SCDT was 18 ± 7 mg (P = 0.53), infused over 14 ± 6 and 14 ± 5 hours, respectively (P = 0.99). In the USAT group, the mean raw pulmonary arterial thrombus score was reduced from 31 ± 4 at baseline to 22 ± 7 (P < 0.001). In the SCDT group, the score was reduced from 33 ± 4 to 23 ± 7 (P < 0.001). There was no significant difference in mean thrombus score reduction between the 2 groups (P = 0.76). The mean reduction in right ventricular/left ventricular ratio from baseline (1.54 ± 0.30 for USAT, 1.69 ± 0.44 for SCDT) to 48 hours was 0.37 ± 0.34 in the USAT group and 0.59 ± 0.42 in the SCDT group (P = 0.01). Major bleeding (1 stroke and 1 vaginal bleed requiring transfusion) occurred in 2 patients, both in the USAT group.

CONCLUSIONS

In the SUNSET sPE (Standard vs. Ultrasound-Assisted Catheter Thrombolysis for Submassive Pulmonary Embolism) trial, patients undergoing USAT had similar pulmonary arterial thrombus reduction compared with those undergoing SCDT, using comparable mean lytic doses and durations of lysis.

Contemporary Catheter-Based Treatment Options for Management of Acute Pulmonary Embolism

Introduction

Acute pulmonary embolism (PE) remains an important cause of cardiovascular mortality and morbidity in the USA and worldwide. Catheter-based therapies are emerging as a new armamentarium for improving outcomes in these patients.

Purpose of review

The purpose of this review is to familiarize the clinicians with (1) various types of catheter-based modalities available for patients with acute PE, (2) advantages, disadvantages, and appropriate patient selection for the use of these devices, and (3) evidence base and the relevance of such therapies in the COVID-19 pandemic.

Recent findings

There are four main types of catheter-based therapies in acute PE: (1) standard catheter-directed thrombolysis (CDT), (2) ultrasound-assisted CDT, (3) pharmacomechanical CDT, and (4) mechanical thrombectomy without thrombolysis. Ultrasound-assisted thrombolysis is the most widely studied modality in this group; however, evidence base for other catheter-based technologies is rapidly emerging.

Summary

Current use of catheter-based therapies is most suitable for patients with intermediate and high-risk acute PE. The adoption of a multidisciplinary approach like the pulmonary embolism response team (PERT) is desirable for appropriate patient selection and possibly/potentially improving patient outcomes. We discuss the current status of these therapies.

Clinical outcomes of very elderly patients treated with ultrasound-assisted catheter-directed thrombolysis for pulmonary embolism: a systematic review

Pulmonary embolism (PE) is a significant cause of death in the very elderly (≥ 75 years) population. Ultrasound-assisted catheter-directed thrombolysis (USCDT) emerges to improve thrombolysis safety and efficacy. However, outcomes in very elderly patients are unknown, as randomized controlled trials exclude this population. Recently, we demonstrated acute kidney injury (AKI) and ischemic hepatitis in an octogenarian intermediate-risk PE patient treated with USCDT. Considering the lack of evidence, we undertook a systematic review to evaluate the clinical outcomes in very elderly PE patients treated with USCDT. We searched for very elderly PE patients treated with USCDT from 2008 to 2019. Additionally, we conducted another systematic review without age restriction to update previous evidence and compare both populations. We also did an exploratory analysis to determine if thrombolysis was followed based on current guidelines or impending clinical deterioration factors. We identified 18 very elderly patients (age 79.2, 75-86), mostly female and with intermediate-risk PE. We found an intracranial hemorrhage (ICH), and a right pulmonary artery rupture. Additionally, two significant bleedings complicated with transient AKI, and one case of AKI and ischemic hepatic injury. The patients who survived all had clinical and echocardiographic in-hospital improvement. Despite low rt-PA doses, ICH and major bleeding remain as feared complications. Thrombolysis decision was driven by impending clinical deterioration factors instead of international guideline recommendations. Our data do not suggest prohibitive risk associated with USCDT in very elderly intermediate and high-risk PE patients. Despite long-term infusions and right ventricular dysfunction, AKI and ischemic hepatic injury were infrequent.

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.

Massive Pulmonary Embolism with Cardiac Arrest during Routine Tibial Bypass Surgery

We report the case of a massive pulmonary embolism with intraoperative cardiac arrest in a 48-year-old male during routine surgical tibial bypass successfully managed by catheter-based interventions. Our experience supports the trending shift in pulmonary embolism therapy guidelines to include endovascular approaches and emphasizes the need for vascular surgeons to adapt their training protocols.

Management of Acute Pulmonary Embolism

Purpose of the Review

Over 100,000 cardiovascular-related deaths annually are caused by acute pulmonary embolism (PE). While anticoagulation has historically been the foundation for treatment of PE, this review highlights the recent rapid expansion in the interventional strategies for this condition.

Recent Findings

At the time of diagnosis, appropriate risk stratification helps to accurately identify patients who may be candidates for advanced therapeutic interventions. While systemic thrombolytics (ST) is the mostly commonly utilized intervention for high-risk PE, the risk profile of ST for intermediate-risk PE limits its use. Assessment of an individualized patient risk profile, often via a multidisciplinary pulmonary response team (PERT) model, there are various interventional strategies to consider for PE management. Novel therapeutic options include catheter-directed thrombolysis, catheter-based embolectomy, or mechanical circulatory support for certain high-risk PE patients. Current data has established safety and efficacy for catheter-based treatment of PE based on surrogate outcome measures. However, there is limited long-term data or prospective comparisons between treatment modalities and ST. While PE diagnosis has improved with modern cross-sectional imaging, there is interest in improved diagnostic models for PE that incorporate artificial intelligence and machine learning techniques.

Summary

In patients with acute pulmonary embolism, after appropriate risk stratification, some intermediate and high-risk patients should be considered for interventional-based treatment for PE.

Reperfusion therapies in pulmonary embolism-state of the art and expert opinion: A position paper from the "Unité de Soins Intensifs de Cardiologie" group of the French Society of Cardiology

Acute pulmonary embolism is a frequent cardiovascular emergency with an increasing incidence. The prognosis of patients with high-risk and intermediate-high-risk pulmonary embolism has not improved over the last decade. The current treatment strategies are mainly based on anticoagulation to prevent recurrence and reduce pulmonary vasculature obstruction. However, the slow rate of thrombus lysis under anticoagulation is unable to acutely decrease right ventricle overload and pulmonary vasculature resistance in patients with severe obstruction and right ventricle dysfunction. Therefore, patients with high-risk and intermediate-high-risk pulmonary embolism remain a therapeutic challenge. Reperfusion therapies may be discussed for these patients, and include systemic thrombolysis, catheter-directed therapies and surgical thrombectomy. High-risk patients require systemic thrombolysis, but may have contraindications as a result of the high risk of bleeding. In addition, intermediate-high-risk patients should not receive systemic thrombolysis, despite its high efficacy, because of prohibitive bleeding complications. Recently, percutaneous reperfusion techniques have been developed to acutely decrease pulmonary vascular obstruction with lower-dose or no thrombolytic agents and, thus, potentially higher safety than systemic thrombolysis. Some of these techniques improve key haemodynamic variables. Cardiac surgical techniques and venoarterial extracorporeal membrane oxygenation as temporary circulatory support may be useful in selected cases. The development of pulmonary embolism centres with multidisciplinary pulmonary embolism teams is mandatory to enable adequate use of reperfusion and improve outcomes. We aim to present the state of the art regarding reperfusion therapies in pulmonary embolism, but also to provide guidance on their indications and patient selection.

One-Year Echocardiographic, Functional, and Quality of Life Outcomes After Ultrasound-Facilitated Catheter-Based Fibrinolysis for Pulmonary Embolism

Accelerated tPA (tissue-type plasminogen activator) dosing regimens for ultrasound-facilitated, catheter-directed fibrinolysis improve short-term computed tomographic-measured right ventricular (RV)-to-left ventricular diameter ratio in massive and submassive pulmonary embolism. The impact on RV remodeling, functional status, and quality of life over the long-term remains unclear.

Interventional Therapies in Acute Pulmonary Embolism

Treatment of acute pulmonary embolism (PE) historically included anticoagulation and systemic thrombolytic therapy. More recently, catheter guided interventions provided promise of mitigating bleeding risks usually associated with systemic thrombolysis in intermediate to high risk PE patients. Catheter based interventions can broadly be divided into catheter directed thrombolysis and catheter based embolectomy. Both modalities are currently undergoing active research and each has their respective risks and benefits. The decision to administer these advanced therapies for acute PE can be challenging but can be accomplished via a multi-disciplinary PE response team.

Comparison of Ultrasound-Accelerated Versus Multi-Hole Infusion Catheter-Directed Thrombolysis for the Treatment of Acute Limb Ischemia

Objective:

Thrombolytic therapy is widely used in the treatment of arterial occlusions causing acute limb ischemia (ALI); however, knowledge regarding the efficacy of the different catheter systems available is scarce. The objective of this study was to compare the safety and efficacy of 2 catheter-directed infusion systems for intra-arterial thrombolysis in the setting of ALI.

Methods:

A retrospective analysis was conducted to study all catheter-directed thrombolysis procedures performed over 32 months in patients diagnosed with ALI. Patients with thrombosis in both native arteries and bypass grafts were included. Patients with contraindications to thrombolysis, or those receiving thrombolysis for deep venous thrombosis, were excluded. The duration of thrombolysis, amount of thrombolytic agent, and technical success rate were recorded. Technical success was defined as complete or near-complete resolution of thrombus burden, allowing for further intervention. Data were stratified to include location of thrombus, procedural complications, mortality, and rates of limb loss.

Results:

Ninety-one patients met inclusion criteria. Among them, Uni-Fuse and EKOS catheters were used in 69 and 22 patients, respectively. The mean age of the population was 71 (standard deviation [SD]: ±1.5) for patients treated with the EKOS catheter and 70 years (SD: ±2.6) for patients receiving thrombolysis with Uni-Fuse. There was no significant difference in the mean infusion duration (1.65 vs 1.9 days), volume of tissue plasminogen activator (44.6 vs 48.2 mg), or technical success rate (72% vs 86%) between the Uni-Fuse and EKOS cohorts ( P > .3). Furthermore, there was no difference in major limb loss or compartment syndrome between each group ( P > .4). The overall complication rate was 14% in both groups, with a 30-day mortality rate of 4% when treated with either catheter system.

Conclusion:

This study suggests that a standard multi-hole infusion catheter demonstrates similar clinical safety and efficacy as the ultrasound-accelerated EKOS system in the treatment of ALI.