Ultrasound-Assisted Catheter-Directed Thrombolysis for Submassive Pulmonary Embolism

Anticoagulant Impact on Clinical Outcomes of Pulmonary Embolism Compared With Thrombolytic Therapy; Meta-Analysis

BACKGROUND

Pulmonary embolism (PE) is a critical condition requiring effective management strategies. Several options are available, including thrombolytic therapy and anticoagulants.

OBJECTIVES

To assess the impact of thrombolytic therapy either combined with anticoagulant (AC) or alone versus AC alone on mortality, recurrence, clinical deterioration, bleeding, and hospital stay.

METHOD

This study included 25 previously published studies from 1990 to 2023, with a total of 12 836 participants. Dichotomous and continuous analysis models were used to evaluate outcomes, with heterogeneity and publication bias tests applied. A random model was used for data analysis. Several databases were searched for the identification and inclusion of studies, such as Ovid, PubMed, Cochrane Library, Google Scholar, and Embase.

RESULTS

For sub-massive PE, CDT plus AC significantly reduced in-hospital, 30-day, and 12-month mortality compared to AC alone, odds ratio (OR) of -0.99 (95% CI [-1.32 to -0.66]), with increased major bleeding risk but no difference in minor bleeding or hospital stay, OR = 0.46, 95% CI [-0.03 to 0.96]). For acute intermediate PE, systemic thrombolytic therapy did not affect all-cause or in-hospital mortality but increased minor bleeding, reduced recurrent PE, and prevented clinical deterioration. The heterogeneity of different models in the current study varied from 0% to 37.9%.

CONCLUSION

The addition of CDT to AC improves mortality outcomes for sub-massive PE but raises the risk of major bleeding. Systemic thrombolytic therapy reduces recurrence and clinical decline in acute intermediate PE despite increasing minor bleeding. Individualized patient assessment is essential for optimizing PE management strategies.

A comparison of the efficacy and safety between anticoagulation alone and combined with catheter-directed thrombolysis for treatment of pulmonary embolism on outcome: A systematic review and meta-analysis

BACKGROUND

Catheter-directed thrombolysis (CDT) is one of the newest treatment options for submassive pulmonary embolism (sPE). This study will compare the efficacy and safety of catheter-directed thrombolysis (CDT) combine with anticoagulation versus anticoagulation alone (AC) in patients with PE.

METHODS

A database search was conducted using PubMed, EMBASE, Cochrane Library, and Clinicaltrials.gov for trials that compared CDT with AC in patients with pulmonary embolism. The primary outcomes was1-year mortality. The secondary outcomes were in-hospital, 30 days, 90 days mortality, in-hospital major and minor bleeding (Thrombolysis in Myocardial Infarction (TIMI) classification), length of hospital stay (LOS), reduction of pulmonary arterial systolic pressure (PASP) and RV/LV diameter ratio.

RESULTS

A total of 16 articles (3 RCTs and 13 non-RCTs) and 10595 patients were included in this study. 2237 patients were in the CDT group and 8358 patients were in the AC group. CDT group was associated with significantly lower in-hospital mortality (2.1% vs 6.2%,OR:0.36, 95%CI:0.26-0.51, p < .00001,I2 = 0%), 30 days mortality (3.1% vs 8.6%,OR:0.39,95%CI:0.23-0.66, p = .0005, I2 = 0%), 90 days mortality (3.8% vs 7.7%,OR:0.49,95%CI:0.29-0.80,p = .005,I2 = 7%), 1-year mortality (6.1% vs 11%, OR:0.51, 95%CI:0.35-0.76, p = .0008,I2 = 36%) compared to AC group, especially in ultrasound-assisted thrombolysis (USAT) subgroup. There were no differences on major bleeding between two groups (1.8% vs 2.2%, OR:1.10, 95%CI:0.61-1.98, p = .75, I2 = 0%). Minor bleeding was significantly higher in CDT group than AC group (6.2% vs 3.8%, OR:1.93,95%CI:1.27-2.94.66, p = .002, I2 = 1%). CDT group significantly reduced PASP (WMD:11.90,95%CI:6.45-17.35, p < .0001, I2 = 72%) and RV/LV (WMD:0.17,95%CI:0.04-0.30, p = .009, I2 = 69%) rapidly than AC group after treatment. LOS was similar between two groups (WMD:0.02,95%CI: -0.68-0.73, p = .95, I2 = 51%).

CONCLUSION

Results thus confirmed that CDT reduced in-hospital, 30 days, 90 days and 1-year all-cause mortality in patients with sPE compared to AC, particularly in USAT subgroup. Nonetheless, CDT group was associated with a higher risk of minor bleeding.

Factors associated with bleeding after ultrasound-assisted catheter-directed thrombolysis for the treatment of pulmonary embolism

Ultrasound-assisted catheter directed thrombolysis (US-CDT) is frequently used for the treatment of pulmonary embolism. Due to the variety of thrombolytic and anticoagulant dosing utilized in practice, patients with pulmonary embolism who undergo US-CDT may be at an increased risk of bleeding. The primary objective of this study was to determine factors associated with major bleeding occurring with US-CDT. Secondary outcomes included in-hospital mortality and ventilator-free days. This multicentre retrospective cohort study evaluated inpatients diagnosed with pulmonary embolism and treated with US-CDT and systemic anticoagulation. A total of 173 patients were included. Most patients receiving US-CDT had a submassive pulmonary embolism with a median Pulmonary Embolism Severity Index (PESI) score of 85. Major bleeding events occurred in 37 of the 173 patients (21%). In-hospital mortality occurred in four (11%) of the patients who experienced major bleeding and three (2%) patients who did not experience major bleeding (P = 0.04). Factors associated with a higher risk of major bleeding included female sex and anticoagulation strategy. The odds of major bleeding were 3.3 times higher for women than for men (odds ratio = 3.32, 95% confidence interval 1.29-8.54). In addition, for each second increase in goal aPTT the odds of major bleeding increased by 5% (odds ratio = 1.05, 95% confidence interval 1.02-1.09). In patients with pulmonary embolism treated with US-CDT, major bleeding may be underestimated. In this analysis, major bleeding was associated with female sex and higher goal aPTT levels. In addition, bleeding with US-CDT was associated with a higher risk of in-hospital mortality.

Recent ultrasound advancements for the manipulation of nanobiomaterials and nanoformulations for drug delivery

Recent advances in ultrasound (US) have shown its great potential in biomedical applications as diagnostic and therapeutic tools. The coupling of US-assisted drug delivery systems with nanobiomaterials possessing tailor-made functions has been shown to remove the limitations of conventional drug delivery systems. The low-frequency US has significantly enhanced the targeted drug delivery effect and efficacy, reducing limitations posed by conventional treatments such as a limited therapeutic window. The acoustic cavitation effect induced by the US-mediated microbubbles (MBs) has been reported to replace drugs in certain acute diseases such as ischemic stroke. This review briefly discusses the US principles, with particular attention to the recent advancements in drug delivery applications. Furthermore, US-assisted drug delivery coupled with nanobiomaterials to treat different diseases (cancer, neurodegenerative disease, diabetes, thrombosis, and COVID-19) are discussed in detail. Finally, this review covers the future perspectives and challenges on the applications of US-mediated nanobiomaterials.

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.

Continuous Aspiration Thrombectomy in High- and Intermediate-High-Risk Pulmonary Embolism in Real-World Clinical Practice

Objectives

We sought to assess the technical and clinical feasibility of continuous aspiration catheter-directed mechanical thrombectomy (CDT) in patients with high- or intermediate-high-risk pulmonary embolism (PE).

Methods and Results

Fourteen patients (eight women and six men; age range: 29–71 years) with high- or intermediate-high-risk PE and contraindications to or ineffective systemic thrombolysis were prospectively enrolled between October 2018 and February 2020. The Indigo Mechanical Thrombectomy System (Penumbra, Inc., Alameda, California) was used as CDT device. Low-dose local thrombolysis (alteplase, 3–12 mg) was additionally applied in three patients. Technical and procedural success was achieved in 14 patients (100%). Complete or nearly complete clearance of pulmonary arteries was achieved in nine patients (64.3%), whereas partial clearance was achieved in five (35.7%). A significant improvement in the pre- and postprocedural patients' clinical status was observed in the following fields (median; interquartile range): heart rate (110; 100–120/min vs. 85; 80–90/min; p < 0.0001), systolic blood pressure (106; 90–127 mmHg vs. 123; 110–133 mmHg; p = 0.049), arterial oxygen saturation (88.5; 84.2–93% vs. 95.0; 93.8–95%, p = 0.0051), pulmonary artery systolic pressure (55; 44–66 mmHg vs. 42; 34–53 mmHg; p = 0.0015), Miller index score (21.5; 20–23 vs. 9.5; 8–13; p < 0.0001) and right ventricular/left ventricular ratio (1.3; 1.3–1.5 vs. 1.0; 0.9–1.0; p < 0.0001). No major periprocedural bleeding was detected.

Conclusions

CDT is a feasible and promising technique for management of high- or intermediate-high-risk PE to decrease thrombus burden, reduce right heart strain, and improve hemodynamic and clinical status. Some patients may benefit from simultaneous local low-dose thrombolytic therapy. Nevertheless, its criteria and role in CTD-managed patients require further elucidation.

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.

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.

Submassive Pulmonary Embolism: A Re-evaluation of Hemodynamic Instability

Current medical management of pulmonary embolism (PE) is driven by risk stratification, with thrombolytic treatment reserved for patients with hemodynamic instability. We describe a case of a man with acute submassive bilateral pulmonary emboli and a right popliteal deep vein thrombosis (DVT), who had persistent shortness of breath, tachycardia, and hypoxemia but remained normotensive and was therefore not treated with thrombolytics until he suffered a fatal cardiac arrest on hospital day six. We examine the indications, risks, and potential benefits of thrombolytic treatment in patients with submassive PE who exhibit signs of instability but do not meet current indications for thrombolytic treatment with persistent hypotension or shock.

Treatment of the acute severe pulmonary embolism using endovascular methods

Purpose

To present a single-centre experience with endovascular treatment of patients with severe symptoms secondary to acute pulmonary embolism (PE).

Material and methods

Twenty-five patients were treated due to contraindications or deficient effects of systemic thrombolytic therapy. The patients were treated with a combination of fragmentation and aspiration, only aspiration, or only fragmentation, and with catheter-directed thrombolytic therapy.

Results

The saturation was improved following treatment in all patients, except in one where the procedure could not be completed. There were no immediate or late procedure-related complications.

Conclusions

Endovascular treatment of severe PE is a safe and efficient option in patients with failing effect or contraindication to systemic thrombolysis.