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

Safety and efficacy of clot-dissolving therapies for submassive pulmonary embolism: A network meta-analysis of randomized controlled trials

BACKGROUND

Acute pulmonary embolism (PE) is a serious condition that needs quick and effective treatment. Anticoagulation therapy is the usual care for most PE patients but may not work well for higher-risk ones. Thrombolysis breaks the clot and improves blood flow. It can be given systemically or locally. Ultrasound-assisted catheter-directed thrombolysis (USAT) is a new technique that boosts clot-busting drugs. This network meta-analysis compares death, bleeding, and benefits of four treatments in acute submassive PE.

METHODS

We comprehensively searched relevant databases up to July 2023 for RCTs. The outcomes encompassed all-cause mortality, major and minor bleeding, PE recurrence, and hospital stay duration. Bayesian network meta-analysis computed odds ratios (OR) and 95 % CI estimates.

RESULTS

In this network meta-analysis of 23 RCTs involving 2521 PE patients, we found that SCDT had the most favorable performance for mortality, as it had the lowest odds ratio (OR) among the four interventions (OR 5.41e-42; 95 % CI, 5.68e-97, 1.37e-07). USAT had the worst performance for major bleeding, as it had the highest OR among the four interventions (OR 4.73e+04; 95 % CI, 1.65, 9.16e+13). SCDT also had the best performance for minor bleeding, as it had the lowest OR among the four interventions (OR 5.68e-11; 95 % CI, 4.97e-25, 0.386).

CONCLUSION

Our meta-analysis suggests that SCDT is the most effective treatment intervention in improving the risks of All-cause mortality and bleeding. Thrombolytic therapy helps in improving endpoints including the risk of PE recurrence and the duration of hospital stay.

Right Ventricular Recovery: Early and Late Changes after Acute PE Diagnosis

Right ventricular (RV) failure is a critical cause of morbidity and mortality in patients presenting with pulmonary embolism (PE). The presentation of RV failure is based on the combination of clinical findings, laboratory abnormalities, and imaging evidence. An improved understanding of the pathophysiology of RV dysfunction following PE has given rise to more accurate risk stratification and broader therapeutic approaches. A subset of patients with PE develop chronic RV dysfunction with or without pulmonary hypertension. In this review, we focus on the impact of PE on the RV and its implications for risk stratification, prognosis, acute management, and long-term therapy.

Outcomes in High-Risk Pulmonary Embolism Patients Undergoing FlowTriever Mechanical Thrombectomy or Other Contemporary Therapies: Results From the FLAME Study

BACKGROUND

Hemodynamically unstable high-risk, or massive, pulmonary embolism (PE) has a reported in-hospital mortality of over 25%. Systemic thrombolysis is the guideline-recommended treatment despite limited evidence. The FLAME study (FlowTriever for Acute Massive PE) was designed to generate evidence for interventional treatments in high-risk PE.

METHODS

The FLAME study was a prospective, multicenter, nonrandomized, parallel group, observational study of high-risk PE. Eligible patients were treated with FlowTriever mechanical thrombectomy (FlowTriever Arm) or with other contemporary therapies (Context Arm). The primary end point was an in-hospital composite of all-cause mortality, bailout to an alternate thrombus removal strategy, clinical deterioration, and major bleeding. This was compared in the FlowTriever Arm to a prespecified performance goal derived from a contemporary systematic review and meta-analysis.

RESULTS

A total of 53 patients were enrolled in the FlowTriever Arm and 61 in the Context Arm. Context Arm patients were primarily treated with systemic thrombolysis (68.9%) or anticoagulation alone (23.0%). The primary end point was reached in 9/53 (17.0%) FlowTriever Arm patients, significantly lower than the 32.0% performance goal (P<0.01). The primary end point was reached in 39/61 (63.9%) Context Arm patients. In-hospital mortality occurred in 1/53 (1.9%) patients in the FlowTriever Arm and in 18/61 (29.5%) patients in the Context Arm.

CONCLUSIONS

Among patients selected for mechanical thrombectomy with the FlowTriever System, a significantly lower associated rate of in-hospital adverse clinical outcomes was observed compared with a prespecified performance goal, primarily driven by low all-cause mortality of 1.9%.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04795167.

Catheter-directed thrombolysis compared with systemic thrombolysis and anticoagulation in patients with intermediate- or high-risk pulmonary embolism: systematic review and network meta-analysis

BACKGROUND

Therapeutic options for intermediate- or high-risk pulmonary embolism (PE) include anticoagulation, systemic thrombolysis and catheter-directed thrombolysis (CDT); however, the role of CDT remains controversial. We sought to compare the efficacy and safety of CDT with other therapeutic options using network meta-analysis.

METHODS

We searched PubMed (MEDLINE), Embase, ClinicalTrials.gov and Cochrane Library from inception to Oct. 18, 2022. We included randomized controlled trials and observational studies that compared therapeutic options for PE, including anticoagulation, systemic thrombolysis and CDT among patients with intermediate- or high-risk PE. The efficacy outcome was in-hospital death. Safety outcomes included major bleeding, intracerebral hemorrhage and minor bleeding.

RESULTS

We included data from 44 studies, representing 20 006 patients. Compared with systemic thrombolysis, CDT was associated with a decreased risk of death (odd ratio [OR] 0.43, 95% confidence interval [CI] 0.32-0.57), intracerebral hemorrhage (OR 0.44, 95% CI 0.29-0.64), major bleeding (OR 0.61, 95% CI 0.53-0.70) and blood transfusion (OR 0.46, 95% CI 0.28-0.77). However, no difference in minor bleeding was observed between the 2 therapeutic options (OR 1.11, 95% CI 0.66-1.87). Compared with anticoagulation, CDT was also associated with decreased risk of death (OR 0.36, 95% CI 0.25-0.52), with no increased risk of intracerebral hemorrhage (OR 1.33, 95% CI 0.63-2.79) or major bleeding (OR 1.24, 95% CI 0.88-1.75).

INTERPRETATION

With moderate certainty of evidence, the risk of death and major bleeding complications was lower with CDT than with systemic thrombolysis. Compared with anticoagulation, CDT was associated with a probable lower risk of death and a similar risk of intracerebral hemorrhage, with moderate certainty of evidence. Although these findings are largely based on observational data, CDT may be considered as a first-line therapy in patients with intermediate- or high-risk PE.

PROTOCOL REGISTRATION

PROSPERO - CRD42020182163.

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.

Pulmonary Embolism in Transit Across a Patent Foramen Ovale

A pulmonary embolism (PE) is an obstruction in a pulmonary artery, and a saddle PE occurs when the obstruction is lodged in the main pulmonary trunk and spans the left and right pulmonary arteries. The current case study describes complications of a thrombus in transit across a patent foramen ovale (PFO). A 35-year-old female presented to the emergency department after a nontraumatic syncopal fall. She had recently returned from a cross-country flight 10 days before and had noticed left calf tenderness when exiting the plane. Vitals were notable for sinus tachycardia at 120 bpm. An electrocardiogram indicated an S1Q3T3 pattern, and chest computed tomographic angiography was positive for a saddle PE. A 2D (two-dimensional) transthoracic echocardiogram showed right ventricular free wall hypokinesis and McConnell’s sign. Echocardiogram findings were concomitant with a thrombus in transit across the interatrial septum, indicating a possible PFO. An emergency pulmonary embolectomy with cardiopulmonary bypass and closure of her PFO was performed the following morning and complicated by cardiogenic shock and subsequent cardiac arrest. The patient was resuscitated in the operating room but failed to be removed from cardiopulmonary bypass, requiring low-dose inotropic support and venoarterial extracorporeal membrane oxygenation flow at 4 L/min. After a repeat right pulmonary artery thrombectomy and two subsequent transesophageal echocardiograms indicated stable right ventricular systolic function, decannulation was performed. The patient was discharged on day 17 with long-term anticoagulation and home healthcare. In the current case report, the patient’s unstable and deteriorating condition was complicated by unusual findings of a thrombus in transit across a PFO. These additional echocardiogram findings represented an unusual case that warranted surgical treatment instead of systemic thrombolysis therapy because of the increased risk of systemic clot embolization.

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 safety and efficacy of systemic versus catheter-based therapies: application of a prognostic model by a pulmonary embolism response team

The decision by pulmonary embolism response teams (PERTs) to utilize anticoagulation (AC) with or without systemic thrombolysis (ST) or catheter-directed therapies (CDT) for pulmonary embolism (PE) is a balance between the desire for a positive outcome and safety. Our primary aim was to develop a predictive model of in-hospital mortality for patients with high- or intermediate-risk PE managed by PERT while externally validating this model. Our secondary aim was to compare the relative safety and efficacy of ST and CDT in this cohort. Consecutive patients hospitalized between June 2014 and January 2020 at the Cleveland Clinic Foundation and The University of Rochester with acute high- or intermediate-risk PE managed by PERT were retrospectively evaluated. Groups were stratified by treatment strategy. The primary outcome was in-hospital mortality, and secondary outcome was major bleeding. A logistic regression model to predict the primary outcome was built using the derivation cohort, with 100-fold bootstrapping for internal validation. External validation was performed and the area under the receiver operating curve (AUC) was calculated. Of 549 included patients, 421 received AC alone, 71 received ST, and 64 received CDT. Predictors of major bleeding include ESC risk category, PESI score, hypoxia, hemodynamic instability, and serum lactate. CDT trended towards lower mortality but with an increased risk of bleeding relative to ST (OR = 0.42; 95% CI [0.15, 1.17] and OR = 2.14; 95% CI [0.9, 5.06] respectively). In the multivariable logistic regression model in the derivation institution cohort, predictors of in-hospital mortality were age, cancer, hemodynamic instability requiring vasopressors, and elevated NT-proBNP (AUC = 0.86). This model was validated using the validation institution cohort (AUC = 0.88). We report an externally-validated model for predicting in-hospital mortality in patients with PE managed by PERT. The decision by PERT to initiate CDT or ST for these patients had no impact on mortality or major bleeding, yet the long-term efficacy of these interventions needs to be elucidated.

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.

Catheter Directed Interventions for pulmonary embolism: Institutional Trends over a Decade 2010-2019

OBJECTIVES

Catheter Directed Interventions (CDIs) are commonly performed for acute Pulmonary Embolism (PE). The evolving catheter types and treatment algorithms impact the utilization and outcomes of these interventions. This study aimed to investigate the changes in CDI practice and their impact on outcomes.

METHODS

Patients who underwent CDIs for PE between 2010 and 2019 at a single institution were identified from a prospectively maintained database. A PE team was launched in 2012, and in 2014 was established as an official Pulmonary Embolism Response Team (PERT). CDI annual usage trends and clinical failures were recorded. Clinical success was defined as physiologic improvement in the absence of major bleeding, perioperative stroke or other procedure-related adverse event, decompensation for sub-massive or persistent shock for massive PE, need for surgical thromboembolectomy or death. Major bleeding was defined as requiring a blood transfusion, a surgical intervention, or suffering from an intracranial hemorrhage.

RESULTS

372 patients received a CDI for acute PE during the study period: age 58.9±15.4 years, males 187 (50.3%), sub-massive PE 340 (91.4%). CDI showed a steep increase in the early PERT years, peaking in 2016 with a subsequent decline. Ultrasound-assisted thrombolysis was the predominant CDI technique peaking at 84% of all CDI in 2014. Suction thrombectomy utilization peaked at 15.2% of CDI in 2019. Mean alteplase dose with catheter thrombolysis techniques decreased from 26.8±12.5mg in 2013 to 13.9±7.5mg in 2019 (P<.001). Mean lysis time decreased from 17.2±8.3 hours in 2013 to 11.3±8.2 hours in 2019 (P<.001). Clinical success for the massive and the submassive PE cohorts was 58.1% and 91.2% respectively; the major bleed rate was 25.0% and 5.3%. There were two major clinical success peaks, one in 2015 mirroring our technical learning curve and one in 2019 mirroring our patient selection learning curve. The clinical success drop in 2018 was primarily derived from blood transfusions due to acute blood loss during suction thrombectomy.

CONCLUSIONS

CDIs for acute PE have rapidly evolved with high success rates. Multidisciplinary approaches amongst centers with appropriate expertise are advisable for the safe and successful implementation of catheter interventions.

In-hospital outcomes of catheter-directed thrombolysis in patients with pulmonary embolism

AIMS

Catheter-directed treatment of acute pulmonary embolism (PE) is technically advancing. Recent guidelines acknowledge this treatment option for patients with overt or imminent haemodynamic decompensation, particularly when systemic thrombolysis is contraindicated. We investigated patients with PE who underwent catheter-directed thrombolysis (CDT) in the German nationwide inpatient cohort.

METHODS AND RESULTS

Data from hospitalizations with PE (International Classification of Disease code I26) between 2005 and 2016 were collected by the Federal Office of Statistics in Germany. Patients with PE who underwent CDT (OPS 8-838.60 or OPS code 8-83b.j) were compared with patients receiving systemic thrombolysis (OPS code 8-020.8), and those without thrombolytic or other reperfusion treatment. The analysis was not prespecified; therefore, our findings can only be considered to be hypothesis generating. We analysed data from 978 094 hospitalized patients with PE. Of these, 41 903 (4.3%) patients received thrombolytic treatment [systemic thrombolysis in 4.2%, CDT in 0.1% (1175 patients)]. Among patients with shock, CDT was associated with lower in-hospital mortality compared to systemic thrombolysis [odds ratios (OR) 0.30 (95% 0.14-0.67); P = 0.003]. Intracranial bleeding occurred in 14 (1.2%) patients who received CDT. Among haemodynamically stable patients with right ventricular dysfunction (intermediate-risk PE), CDT also was associated with a lower risk of in-hospital mortality compared to systemic thrombolysis {OR 0.55 [95% confidence interval (CI) 0.40-0.75]; P < 0.001} or no thrombolytic treatment [0.45 (95% CI 0.33-0.62); P < 0.001].

CONCLUSION

In the German nationwide inpatient cohort, based on administrative data, CDT was associated with lower in-hospital mortality rates compared to systemic thrombolysis, but the overall rate of intracranial bleeding in patients who received CDT was not negligible. Prospective controlled data are urgently needed to determine the true value of this treatment option in acute PE.

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.

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.

Intra-clot Microbubble-Enhanced Ultrasound Accelerates Catheter-Directed Thrombolysis for Deep Vein Thrombosis: A Clinical Study

Insufficiency of microbubbles in the vessel-obstructing thrombus significantly reduces the effectiveness of ultrasound thrombolysis. With catheter-directed thrombolysis (CDT), microbubbles can be delivered directly into the thrombus. In this study, we combined CDT with intra-clot microbubble-enhanced ultrasound thrombolysis (IMUT) to investigate its safety and efficiency in thrombolysis in patients with acute lower limb deep vein thrombosis (DVT). For IMUT, a 1-MHz air-backed transducer directed 100-μs-pulse-length and 100-Hz-pulse-repetition pressure at 1 MPa was used. Thirteen DVT patients in the study group were treated with CDT and IMUT. Forty-three DVT patients in the historical control group were treated with CDT alone. The results indicated that the average thrombolysis time of the study group was significantly shorter (5.23 ± 1.59 d) than that of the control (10.00 ± 2.69 d), and the overall urokinase dosage of the study group ([3.82 ± 1.68] × 10⁶ IU) was lower than that of the control ([4.99 ± 2.26] × 10⁶ IU). No procedure-related complications were noted in either group. Therefore, combining CDT with IMUT can improve thrombolysis safely and efficiently.