Large-Bore Aspiration Thrombectomy versus Catheter-Directed Thrombolysis for Acute Pulmonary Embolism: A Propensity Score–Matched Comparison

Meta-Analysis of Mechanical Thrombectomy Versus Catheter-Directed Thrombolysis for Pulmonary Embolism

BACKGROUND

Studies have shown variable outcomes regarding catheter-based mechanical thrombectomy (MT) versus catheter-directed thrombolysis (CDT) in patients with pulmonary embolism (PE). We conducted a meta-analysis of the available data.

METHODS

Online databases were searched for studies comparing MT and CDT for PE. The outcomes of interest were procedure time (minutes), fluoroscopy duration (minutes), estimated blood loss (ml), change in mean pulmonary arterial pressure (mPAP, mmHg), change in right ventricle (RV)/left ventricle (LV) ratio, postprocedural intensive care unit (ICU) admission, ICU length of stay (days), hospital length of stay (days), intracranial hemorrhage (ICH), major bleeding, all-cause mortality, PE-related readmission and all-cause readmission. Pooled odds ratios (OR) and standardized mean difference (SMD), along with 95% confidence intervals (CI) were calculated.

RESULTS

A total of 10 studies (1842 patients-852 [MT], 990 [CDT]) were included. The follow up duration varied from in-hospital to 1 year. Mean age was 62 years and 49% of patients were men. As compared to the CDT group, patients undergoing MT had longer procedure time (SMD 6.04, 95% CI 2.46 to 9.62, p = 0.0010), fluoroscopy duration (SMD 1.77, 95% CI 0.84 to 2.71, p = 0.0002), and greater estimated blood loss (SMD 1.56, 95% CI 0.52 to 2.60, p = 0.003), with lower postprocedural ICU admission rate (OR 0.01, 95% CI 0.00 to 0.02, p < 0.00001) and ICU length of stay (SMD -0.53, 95% CI -0.91 to -0.15, p = 0.007). No significant differences were found with respect to changes in mPAP and RV/LV ratio, hospital length of stay, ICH, major bleeding, all-cause mortality, PE-related readmission and all-cause readmission.

CONCLUSION

While CDT is faster and associated with lesser blood loss in patients with PE, the ICU admission rate and length of stay is significantly greater with CDT than MT.

Assessment of Safety and Procedural Learning Curve for Pulmonary Embolism Patients Undergoing Percutaneous Mechanical Thrombectomy

INTRODUCTION

Advancements in percutaneous mechanical thrombectomy (PMT) have emerged as a promising alternative for the treatment of intermediate-risk PE, demonstrating a favorable safety profile and low 30-day mortality. Its adoption and procedural learning curve remain underexplored. This study evaluates the safety, procedural efficiency, and learning curve of PMT over time, using fluoroscopy time, procedure time, and contrast volume as primary metrics.

METHODS

This was a single-institution, multicenter retrospective study of 411 patients who underwent PMT for intermediate-risk PE from January 2020 to July 2024 across three medical centers involving 15 vascular surgeons. High risk patients were excluded from the study. Linear regression analysis assessed trends in procedural efficiency, while segmented regression and cumulative sum (CUSUM) analyses identified learning curve plateaus. T-tests compared hospital and intensive care unit (ICU) length of stay, as well as complication rates between the first 50 and most last 50 cases. Additionally, multivariable regression examined the impact of patient factors-including BMI, sex, age, and comorbidities-on procedural efficiency. All statistical analyses were performed using Python (Python Software Foundation, Wilmington, DE, USA).

RESULTS

Regression analysis revealed statistically significant reductions in fluoroscopy time (R2 = 0.103, p < 0.001), contrast volume (R2 = 0.071, p < 0.001), and procedure time (R2 = 0.068, p < 0.001) over time. Segmented regression identified proficiency plateaus at 55 cases for fluoroscopy time and 138 cases for procedure time. On an individual basis, an estimated 3.4 cases were required to achieve imaging efficiency proficiency and 8.6 cases for procedural proficiency per surgeon. CUSUM analysis demonstrated a consistent negative trend in fluoroscopy time, procedure time, and contrast volume, confirming sustained improvements in procedural efficiency over the study period. T-tests comparing the first and last 50 cases showed no statistically significant differences in hospital length of stay (6.23 vs. 5 days, p = 0.406), ICU length of stay (2.31 vs. 1.23 days, p = 0.256), or complication rate (14% vs. 0%, p = 0.134). The overall mortality rate for the study cohort was 4.49%. No significant trend in 30-day mortality was observed over time, consistent with the low overall mortality rate in this intermediate-risk cohort.

CONCLUSION

PMT for PE demonstrates a favorable learning curve, with significant improvements in procedural efficiency over time. Fluoroscopy time and procedure time plateau at distinct points, reflecting different aspects of skill acquisition though other factors like anatomical variability and operating room staff could have had an impact. The procedure maintains low complication and mortality rates, supporting its safety and feasibility across a range of clinical settings. These findings suggest that PMT can be rapidly adopted by vascular surgeons with minimal impact from patient demographics or comorbidities.

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.

Safety and efficacy of catheter-directed thrombectomy without thrombolysis in acute pulmonary embolism: A systematic review and meta-analysis

BACKGROUND

This meta-analysis aims to investigate the safety and efficacy of catheter-directed thrombectomy (CDT) without using adjunct thrombolysis as reperfusion therapy to manage intermediate and high-risk pulmonary embolism (PE).

METHODS

A literature search of Ovid MEDLINE, Embase, CiNAHL, Cochrane Library, and Web of Science was conducted from inception to January 2024. Eligible studies reported more than 10 patients treated for acute PE with catheter-directed thrombectomy only, who were over 18 years of age. Primary endpoints were major bleeding, in-hospital mortality, and hemodynamic changes.

RESULTS

Eighteen studies (n = 803) were included for quantitative analysis. The pooled estimate of incidences of in-hospital mortality and major bleeding was 1.8 % (95 % CI 0.009, 0.027) and 2.1 % (95 % CI 0.011, 0.031) respectively. A pooled estimate reported a post-procedural increase in oxygen saturation and systolic blood pressure by 8.96 % (95 % CI: 3.54, 14.38) and 15.02 mmHg (95 % CI 6.35, 23.69) respectively. Post-procedural mean pulmonary artery pressure, right ventricle/left ventricle (RV/LV) ratio, and Miller score were reduced by 10.30 mmHg (95 % CI -14.94, -5.66), 0.29 (95 % CI -0.50, -0.08) and 8.09 (95 % CI -10.70, -5.47) respectively.

CONCLUSION

CDT without adjunctive thrombolysis may lead to improvements in hemodynamic outcomes and exhibits favorable safety profiles. This meta-analysis provides a rationale for lowering the threshold for considering this technique, and ongoing randomized trials will further advance the field to determine optimal managment strategies for intermediate and high-risk acute PE.

A Comparison of Postprocedural Hemoglobin in Catheter-Directed Thrombolysis versus Large-Bore Aspiration Thrombectomy for Acute Pulmonary Embolism

PURPOSE

To compare changes in hemoglobin (HB) following catheter-directed thrombolysis (CDT) versus large-bore aspiration thrombectomy (LBAT) of acute pulmonary embolism (PE).

MATERIALS AND METHODS

A single-center retrospective review of patients with acute high- or intermediate-risk PE treated with CDT or LBAT between December 2009 and September 2023 was performed. The LBAT group was divided according to usage of an autotransfusion device (ATD). There were 166 patients in the CDT group (56 years ± 15). LBAT patients were treated without (LBAT, n = 58, 61 years ± 16) or with (LBATw, n = 47, 62 years ± 15) an ATD. Endpoints included change in HB between preprocedural and postprocedural measurements, the 7-day postprocedural nadir (low point), and adverse events (AEs).

RESULTS

The mean HB changes between preprocedural and postprocedural measurements in the CDT, LBAT, and LBATw groups were -1.3 g/dL ± 1.3, -1.6 g/dL ± 0.98, and -1.1 g/dL ± 0.9, respectively (P = .098). The mean HB changes to the 7-day postprocedural nadir in the CDT, LBAT, and LBATw groups were -1.7 g/dL (SD ± 1.4), -2.4 g/dL (SD ± 1.3), and -1.8 g/dL (SD ± 1.3), respectively (P = .008). The minor hemorrhagic AE rates were 3.6% in the CDT group, 12.1% in the LBAT group, and 14.9% in the LBATw group (P = .010). There was no significant difference in moderate (P = .079) and major (P = .529) hemorrhagic AEs between the groups. There were no procedure-related mortalities.

CONCLUSIONS

The use of LBAT without ATD resulted in a significant decrease in HB to the 7-day postprocedural nadir compared with CDT or LBAT with ATD. This did not translate into significantly higher transfusion rates or moderate or major hemorrhagic events. Findings suggest that the decision between CDT and LBAT should not be based solely on the expected blood loss consideration.

Percutaneous Thrombectomy Using a Computer-Assisted Aspiration Device for Deep Vein Thrombosis

PURPOSE

To demonstrate the safety and effectiveness of a computer-assisted large-bore thrombectomy (CA-LBT) device in aspiration thrombectomy for treatment of deep vein thrombosis (DVT).

MATERIALS AND METHODS

A single-institution retrospective review was performed to include 16 consecutive patients (median age, 51.1 years; range, 19-77 years; 5 men and 11 women) who underwent percutaneous thrombectomy using a 16-F CA-LBT device (Lightning Flash Aspiration System; Penumbra, Alameda, California) for DVT (12 iliofemoral occlusions with or without caval extension [75.0%], 3 axillosubclavian occlusions [18.8%], and 1 caval occlusion [6.3%]) between January 2023 and August 2023.

RESULTS

Thrombectomy was performed via the popliteal (n = 10, 62.5%), femoral (n = 3, 18.8%), saphenous (n = 1, 6.3%), brachial (n = 1, 6.3%), and femoral and brachial (n = 1, 6.3%) veins, with a median fluoroscopy time of 17 minutes (range, 7.2-61 minutes) and contrast agent volume of 110 mL (range, 30-175 mL). Restoration of anterograde flow was achieved in all cases (100%, 16/16). Thirteen patients (81.2%) received venoplasty after thrombectomy for residual stenosis. Stents were placed in 7 patients (43.8%). With a median clinical follow-up of 77 days (range, 3-278 days), symptom improvement was achieved among 13 of 15 patients (86.7%) who initially presented with DVT-associated symptoms. Of 14 patients with imaging follow-up, patency was confirmed in 12 (85.7%). Of the 2 patients (14.3%) with complete thrombosis on follow-up imaging, one patient was successfully treated with repeated thrombectomy using CA-LBT technology and the other was treated with systemic anticoagulation.

CONCLUSIONS

Aspiration thrombectomy with this 16-F CA-LBT device is a feasible option for treatment of proximal or large-volume DVT.

Perioperative and intermediate outcomes of patients with pulmonary embolism undergoing catheter-directed thrombolysis vs percutaneous mechanical thrombectomy

OBJECTIVE

Thrombolytic therapy has been a mainstay of treatment for massive or submassive pulmonary embolism (PE), a common and highly morbid pathology. New percutaneous mechanical thrombectomy (PMT) devices have recently become widely available and have been used increasingly for the treatment of acute PE, but evidence demonstrating its efficacy over standard catheter-directed lytic protocol remains limited.

METHODS

Using TriNetX Data Network, a global federated database of >250 million patients, we conducted a retrospective cohort study of patients from January 2017 to August 2023 with a diagnosis of PE, treated with either PMT or catheter-directed thrombolysis (CDT). Eligible patients were 1:1 propensity score-matched for preoperative covariates including demographics and comorbidities. We calculated and compared the 30-day outcomes of all-cause mortality, bleeding complications (blood transfusion, gastrointestinal bleed, and intracranial hemorrhage), diagnosis of acute respiratory failure (RF), myocardial infarction (MI), and pulmonary hypertension (PH) using odds ratios (OR) with 95% confidence intervals (CIs). Also, the 5-year outcomes of all-cause mortality, a composite outcome of chronic PH (chronic PE, chronic cor pulmonale, chronic thromboembolic PH), right heart failure (RHF), RF, and emergency department visits, were compared using hazard ratios (HRs) with 95% CIs.

RESULTS

We identified 2978 patients treated with PMT and 1137 patients treated with CDT. After matching, we compared 1102 patients in each cohort. For 30-day outcomes, all-cause mortality, acute RF, and blood transfusion were similar between the two groups. However, compared with CDT, PMT was associated with a better safety profile, including lower bleeding risk for both ICH (OR, 0.46; 95% CI, 0.24-0.890) and gastrointestinal bleed (OR, 0.42; 95% CI, 0.28-0.63). PMT also demonstrated better immediate functional outcomes, with less PH (OR, 0.53; 95% CI, 0.41-0.68) and MI (OR, 0.54; 95% CI, 0.41-0.76). At 5 years, the all-cause mortality and RF for both procedures were similar, but PMT was associated with lower rates of chronic PH (HR, 0.70; 95% CI, 0.55-0.90), RHF (HR 0.49; 95% CI, 0.37-0.65), and emergency department visits (348 for PMT vs 426 for CDT; P < .01).

CONCLUSIONS

In patients undergoing catheter-based therapy for PE, PMT has an improved procedural safety profile vs CDT and results in significantly fewer 30-day postoperative complications, with fewer bleeding events, and is also associated with fewer periprocedural MIs and less acute PH. Perhaps, more important, PMT also demonstrated improved long-term outcomes with significantly fewer chronic PH and RHF diagnoses with fewer emergency department visits.

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.

Outcomes With Hybrid Catheter-Directed Therapy Compared With Aspiration Thrombectomy for Patients With Intermediate-High Risk Pulmonary Embolism

PURPOSE

Intermediate-high-risk pulmonary embolism (IHR PE) is a challenging form of embolism obstruction that causes right ventricular (RV) dysfunction. The optimal management of IHR PE has not been established. This single-center prospective, observational study aimed to evaluate the efficacy and safety of complex catheter-directed therapy (CDT) - catheter-directed mechanical aspiration thrombectomy (CDMT) supplemented with catheter-directed thrombolysis (hybrid CDT) in comparison to CDMT alone for IHR PE.

METHODS

A propensity score based on the pulmonary embolism severity index class and Miller obstruction index (MOI) was calculated, and 21 hybrid CDT cases (mean age 54.8 (14.7) years, 9/21 women) were matched with 21 CDMT cases (mean age 58.8 (14.9) years, 13/21 women). The baseline demographics, clinical, and treatment characteristics were analyzed.

RESULTS

No significant differences were detected regarding baseline demographics and PE severity parameters. Hybrid CDT demonstrated a higher reduction in mean pulmonary artery pressure (mPAP) (hybrid CDT: median mPAP reduction 8 mmHg (IQR: 6-10 mmHg) vs CDMT: median mPAP reduction 6 mmHg (IQR: 4-7 mmHg); P = 0.019), MOI score (hybrid CDT: median change - 5 points (IQR: 5-6 points) vs CDMT median change - 3 points (IQR: 3-5 points); P = 0.019), and median RV: left ventricular ratio (hybrid CDT: median change 0.4 (IQR: 0.3-0.45) vs CDMT median change 0.26 (IQR: 0.2-0.4); P = 0.007). No major bleeding was observed. Both the hybrid CDT and CDMT alone treatments are safe and effective in managing IHR PE.

CONCLUSIONS

Hybrid CDT is a promising technique for the management of IHR PE with insufficient thrombus load reduction by CDMT.

TRIAL REGISTRATION

NCT0447356-registration date 16 July 2020.

A meta-analysis of outcomes of aspiration thrombectomy for high and intermediate-risk pulmonary embolism

BACKGROUND

Aspiration thrombectomy has gained popularity in patients with massive and sub-massive pulmonary embolism (PE) and having contraindications to thrombolysis.

METHODS

A meta-analysis was conducted including studies on aspiration thrombectomy in patients with high-risk and intermediate-risk PE. The pooled odds ratio for efficacy parameters, including change in heart rate, blood pressure and right ventricle/left ventricle (RV/LV) ratio, and safety parameters including major bleeding and stroke, was calculated using a random effects model.

RESULTS

The meta-analysis of 24 selected studies revealed that intermediate and high-risk pulmonary embolism (PE) patients demonstrated significant improvements: modified Miller score odds ratio of 10.60, mean pulmonary artery pressure reduction by 0.04 mm Hg, and an overall all-cause mortality odds ratio of 0.10. Considerable heterogeneity was observed in various outcomes.

CONCLUSION

Aspiration thrombectomy has success rates in both high-risk and intermediate-risk PE, however, procedural risks, including bleeding, must be anticipated.

Catheter-directed thrombolysis versus thrombectomy for submassive and massive pulmonary embolism: A systematic review and meta-analysis

INTRODUCTION

Controversy surrounds the optimal therapy for submassive and massive pulmonary embolism (PE). We conducted a systematic review and meta-analysis to compare the outcomes of catheter-directed thrombolysis (CDT) versus surgical and catheter-based thrombectomy in patients with submassive and massive PE.

METHODS

We searched PubMed, EMBASE, Cochrane, and Google Scholar for studies comparing outcomes of CDT versus thrombectomy in submassive and massive PE. Studies were identified and data were extracted by two independent reviewers. A random effects model was used to calculate risk ratios (RRs) with 95 % confidence intervals (CIs). Outcomes included in-hospital mortality, procedural complications, hospital and intensive care unit (ICU) length of stay (LOS), 30-day readmissions, and right ventricle/left ventricle (RV/LV) ratio improvement.

RESULTS

Eight observational studies with 1403 patients were included, of whom 50.0 % received CDT. Compared to thrombectomy, CDT was associated with significantly lower in-hospital mortality (RR 0.62; 95 % CI 0.43-0.89; p = 0.01) and similar rates of major bleeding (p = 0.61), blood transfusion (p = 0.41), stroke (p = 0.41), and atrial fibrillation (p = 0.71). The hospital and ICU LOS, 30-day readmissions, and degree of RV/LV ratio improvement were similar between the two strategies (all p > 0.1). In subgroup analyses, in-hospital mortality was similar between CDT and catheter-based thrombectomy (p = 0.48) but lower with CDT compared with surgical thrombectomy (p = 0.01).

CONCLUSIONS

In patients with submassive and massive PE, CDT was associated with similar in-hospital mortality compared to catheter-based thrombectomy, but lower in-hospital mortality compared to surgical thrombectomy. Procedural complications, LOS, 30-day readmissions, and RV/LV ratio improvement were similar between CDT and any thrombectomy. Randomized controlled trials are indicated to confirm our findings.

Cost-Comparison of Mechanical Thrombectomy and Catheter-Directed Thrombolysis in Intermediate-Risk Pulmonary Embolism

Background

Catheter-directed thrombolysis (CDT) and large-bore mechanical thrombectomy (MT) are the leading percutaneous-based therapies for the management of intermediate-risk pulmonary embolism (PE). While previous studies have demonstrated their procedural safety and efficacy, the cost implications of these interventions remain unclear. This study aims to conduct a cost-benefit analysis to evaluate the economic advantages associated with CDT and MT from the perspective of the treating hospital.

Methods

A total of 372 consecutive patients with intermediate-risk acute PE who underwent either MT or CDT at 3 academic centers between 2013 and 2021 were included in this analysis. The costs of care incurred during the index hospitalization for the 2 treatment groups were collected and compared using an adjusted cost model.

Results

This study compared the hospital costs of 226 patients who underwent CDT and 146 patients who underwent MT. In the unadjusted overall cohort, the use of CDT was associated with a numerical but nonsignificant increase in costs amounting to $5120 relative to MT (P = .062). This cost difference was primarily driven by the longer length of stay in the intensive care unit and hospital for CDT patients, particularly earlier in the studied timeframe. However, when accounting for confounders including variations between the treating institutions and the timing of treatment during the study period, the adjusted cost differential between CDT and MT narrowed to $1351 (P = .71).

Conclusions

This multicenter cost analysis does not reveal a clear cost advantage of 1 treatment over the other for intermediate-risk PE. The observed cost differences were influenced by variations in practice patterns across the study period and among the 3 participating institutions. Future efforts should also focus on strategies to reduce the length of stay, improve efficiency, and minimize the overall cost of care for intermediate-risk PE patients.

Residual Pulmonary Vascular Obstruction Following Mechanical Thrombectomy for Submassive Pulmonary Embolism: A Single-Center Analysis

Background

Residual pulmonary vascular obstruction (RPVO) following pulmonary embolism (PE) is associated with residual dyspnea, recurrent venous thromboembolism, and chronic thromboembolic pulmonary hypertension. Historically, acute PE treated with anticoagulation alone results in high rates of significant RPVO. Contemporary treatment of submassive PE often involves catheter-based interventions, including mechanical thrombectomy (MT), although their relation to RPVO is not characterized. In this study, we aimed to evaluate the rate of ≥10% RPVO in patients treated with MT.

Methods

Twenty consecutive patients with submassive PE in a single center underwent MT and subsequent planar ventilation/perfusion scintigraphy scan at a median of 4 months after thrombectomy. A quantitative perfusion score was calculated for each planar ventilation/perfusion scintigraphy study to provide a % perfusion defect. Complete hemodynamic data were collected during the procedure and Miller score was calculated using prepulmonary and postpulmonary angiography. Echocardiographic data were collected prior to, 24 to 48 hours after, and 30 days after the procedure.

Results

Four of 20 patients (20%) had ≥10% RPVO at a median of 4 months follow-up. Following MT, the mean Miller score decreased from 24.5 ± 2.9 to 15.8 ± 3.3 (P < .001) and mean pulmonary artery pressure decreased from 36.1 ± 4.8 mm Hg to 26.8 ± 5.4 mm Hg (P < .001). Right ventricle-to-left ventricle ratio decreased from 1.44 ± 0.2 to 1.05 ± 0.24 by 24 to 48 hours (P < .001) and 0.85 ± 0.1 at 30 days (P < .001) and right ventricular systolic pressure decreased from 63.2 ± 10 mm Hg to 42.1 ± 9.8 mm Hg at 24 to 48 hours (P < .001) and 31.9 ± 10.4 at 30 days (P < .001).

Conclusions

In this prospective study of patients with submassive PE treated with MT, favorable rates of RPVO were noted in comparison to prior studies of anticoagulation alone along with expected acute hemodynamic and echocardiographic improvements. While this study was small in scope, the results suggest the potential for long-term benefits of MT in acute PE in addition to the acute benefits previously described.

Modern Treatment of Pulmonary Embolism (USCDT vs MT): Results From a Real-World, Big Data Analysis (REAL-PE)

Background

Advanced therapies are increasingly utilized to treat pulmonary embolism (PE). A unique data platform allows access to electronic health record data for comparison of the safety of PE therapies.

Methods

All data from Truveta (Truveta, Inc) were analyzed (16 systems, 83,612,413 patients, 535,567 with PE). All patients treated with ultrasound-assisted catheter-directed thrombolysis (USCDT) (Boston Scientific) or mechanical thrombectomy (MT) (Inari Medical) for PE were identified. The primary analysis was based on index procedures performed from January 2009 to May 2023, and contemporary analysis on those performed from January 2018 to May 2023. Bleeding was assessed via direct laboratory analysis and transfusion administration documentation. International Society for Thrombosis and Hemostasis (ISTH) and Bleeding Academic Research Consortium (BARC) 3b definitions were recreated. Multiple logistic regression analysis of major bleeding was performed. In-hospital death and median length of stay were measured.

Results

For the primary analysis, 2259 patients (N = 1577 USCDT, N = 682 MT) and for the contemporary analysis 1798 patients (N = 1137 USCDT, N = 661 MT) met the criteria. Incidence of hemoglobin reduction (>2 and >5 g/dL) and transfusions received were significantly higher among MT-treated patients in both analyses, as was ISTH and BARC 3b major bleeding (primary: ISTH MT 17.3% vs USCDT 12.4% P = .002; BARC 3b MT 15.4% vs USCDT 11.8% P = .019) (contemporary: ISTH MT 17.2% vs USCDT 11.0% P = .0002; BARC 3b MT 15.4% vs USCDT 10.6% P = .002). Regression analysis demonstrated that MT is associated with major bleeding. Median length of stay, all-cause 30-day readmission and in-hospital mortality were similar between groups. Intracranial hemorrhage was more common with MT.

Conclusions

Major bleeding derived from direct laboratory and transfusion data occurred more frequently with MT vs USCDT. Intracranial hemorrhage was more common among MT-treated patients. In the absence of randomized data, these results provide guidance regarding the bleeding risk and safety of strategies for advanced PE therapy.

Mortality across treatment strategies in intermediate-to-high risk pulmonary embolism in the modern era: A meta-analysis of observational studies and RCTs

INTRODUCTION

Pulmonary embolism (PE) represents one of the leading causes of death worldwide and mainly treated with medical management, although the utility of more invasive approaches has emerged more recently. This meta-analysis aims to evaluate the 30-day mortality of intermediate-to-high risk PE across different treatment strategies.

METHODS

A systematic literature review and meta-analysis was conducted using PubMed and Cochrane databases. All studies reporting 30-day mortality rates in intermediate-to-high-risk PE were included. Meta-regression analysis and sensitivity analysis were performed on the primary endpoint, 30-day mortality, and secondary endpoints (RV/LV ratio, mPAP, and long-term mortality, any bleeding events).

RESULTS

Of the 2390 studies published between 2000 and 2022, 76 studies (74 observational and 2 RCTs for a total of 1,194,285 patients in the medical cohort and 3007 in the interventional cohort) were included. The median age was 71.4 (IQR 62.8-77.3) years, 53.6% were women. 30-day mortality in the patients treated with medical management was 9.1% (6.6-12.6). In the interventional cohort, 30-day mortality was 2.1% (1.5-3.1) while the pre- vs post-procedure change in mean difference was -6.1 mmHg (-11.2 to -1.1) for mPAP and - 0.41 (-0.51 to - 0.31) for RV/LV ratio. The overall bleeding rate in the interventional cohort was 4.9% (CI 2.6-8.9), without differences between the two strategies (RR 1.26 CI 0.89-1.78).

CONCLUSION

Intermediate-high-risk mortality in pulmonary embolisms treated with medical management remains high in the modern era. Despite the absence of comparative studies, an interventional approach may have a lower 30-day mortality rate and a good safety profile.

Cardiovascular collapse during mechanical thrombectomy for acute pulmonary embolism and the role of extracorporeal membrane oxygenation in patient rescue

BACKGROUND

Driven by the ability to avoid thrombolytics and provide a one stop procedure with immediate hemodynamic improvement, there has been a dramatic increase in the use of mechanical thrombectomy (MT) devices for the treatment of intermediate-to-high risk pulmonary embolism (PE). This study investigated the incidence and outcomes of cardiovascular collapse during MT procedures and demonstrates the role of extracorporeal membrane oxygenation (ECMO) in salvaging patients.

METHODS

This single-center retrospective review included patients with PE undergoing MT with the FlowTriever device between 2017 and 2022. Patients presenting periprocedural cardiac arrest were identified and their perioperative characteristics and postoperative outcomes were evaluated.

RESULTS

A total of 151 patients with a mean age of 64 ± 14 years who presented with intermediate-to-high risk PE received LBAT procedures during the study period. The simplified PE severity score was ≥1 in 83% of cases and the average RV/LV ratio was 1.6 ± 0.5, with and elevated troponin in 84%. Technical success was achieved in 98.7% and a significant decrease in pulmonary artery systolic pressure (PASP) was observed (37 mm Hg vs 56 mm Hg; P < .0001). Intraoperative cardiac arrest occurred in nine patients (6%). These patients were more likely to present PASP of ≥70 mm Hg (84% vs 14%; P < .001), were more hypotensive upon admission (systolic of 94 ± 14 mm Hg vs 119 ± 23 mm Hg; P = .004), presented lower oxygen saturation levels (87 ± 6% vs 92 ± 6%; P = .023) and were more likely to present with a history of recent surgery (67% vs 18%; P = .004). Four patients were rescued successfully with ECMO and their residual PE was subsequently removed before discharge by surgical embolectomy in two of the four cases and repeat MT in the other two. All five patients (3%) who did not receive ECMO support expired intraoperatively. The overall 30-day mortality was 8% with no death occurring in patients who were salvaged with ECMO.

CONCLUSIONS

Large-bore aspiration thrombectomy for acute PE is associated with favorable technical outcomes, but the concern for acute cardiac decompensation is non-negligible in patients presenting with high-risk features and a PASP of ≥70 mm Hg. ECMO can help to salvage some of these patients and should be considered in the treatment algorithms of patients deemed at high risk.

Case Series of Patients With Intermediate-High Risk Pulmonary Embolism in the Setting of Trauma Undergoing Mechanical Thrombectomy

In patients with pulmonary embolism (PE) in the setting of trauma, administration of fibrinolytic therapy is contraindicated due to high risk of hemorrhage. Several studies have demonstrated the safety and efficacy of mechanical thrombectomy among all-comers with PE as an alternative to catheter-directed thrombolytics. However, the risks and benefits of mechanical thrombectomy treatment for pulmonary embolism in a trauma population are not well established. A retrospective analysis was performed in all patients who presented to Level 1 Trauma Center with acute trauma who were found to have a pulmonary embolism (PE) treated with mechanical thrombectomy. From May 2019 to December 2020, six patients were identified. Average age was 54 years, and four patients were male. Four patients had a saddle PE on computed tomography. All patients had an intermediate-high risk PE with troponin I elevation >0.04 ng/mL (average 0.42 ng/mL). Pulmonary Embolism Severity Index (PESI) score in all six patients was class III or IV. In all patients, the mechanical thrombectomy was performed with mean-PA pressure changing from average 40.33 to 31.5 mmHg. Average Intensive Care Unit (ICU) length of stay post-procedure was five days with two patients not requiring ICU stay. No patient had post-operative bleeding during their index stay. Average hemoglobin drop after mechanical thrombectomy was 1.33 g/dL. One patient died <30 days post-procedure due to septic shock and another >90 days later (5 months) from cardiac arrest from recurrent PE. The other four patients were still living >90 days post-procedure. No immediate or delayed postoperative complications were identified. Mechanical thrombectomy appears to be a safe and effective treatment for patients with recent trauma who have an intermediate-high risk pulmonary embolism.

Large-Bore Mechanical Thrombectomy of Acute Pulmonary Embolism at a Community-Based Hospital: A Case Series

Acute pulmonary embolism (PE) is a common, and sometimes fatal, diagnosis that results in over 11,000 deaths in hospitalized patients in the USA annually. In patients with high-risk or high-intermediate-risk PE and especially in whom thrombolytic therapy is contraindicated, mechanical thrombectomy can be an effective treatment option. This case series outlines three patients with PE who were successfully treated with large bore aspiration thrombectomy by Interventional Radiology at a community-based military treatment facility (MTF). Two patients had presented to the emergency department with acute PE and a third of patients with acute PE were transferred from an outside hospital specifically for mechanical thrombectomy due to a complication from systemic anticoagulation. The patients were categorized as good candidates for immediate large-bore aspiration thrombectomy, a recently added capability at the MTF. The patients showed immediate improvement post-procedure and required only one night admission for observation to the intensive care unit. Implementation of this new capability for patients with acute high-risk or high-intermediate-risk PE or with contraindications to thrombolysis provides an alternative treatment with immediate, life-saving capability.

The many roles of urgent catheter interventions: from myocardial infarction to acute stroke and pulmonary embolism

INTRODUCTION

Cardiovascular diseases (CVDs) are the leading cause of cardiovascular mortality and a major contributor to disability worldwide. The prevalence of CVDs is continuously increasing, and from 1990 to 2019, it has doubled. Global cardiovascular mortality has increased from 12.1 million in 1990 to 18.6 million cases in 2019. The development of therapeutic options for these diseases is at the forefront of interest concerning the extensive socio-economic consequences. Modern endovascular transcatheter therapeutic options contribute to the reduction of cardiovascular morbidity and mortality.

AREAS COVERED

The article concentrates on the triad of the most common causes of acute cardiovascular mortality and morbidity - myocardial infarction, ischemic stroke, and pulmonary embolism. Current evidence-based indications, specific interventional techniques, and remaining unsolved issues are reviewed and compared. A personal perspective on the possible implications for the future is provided.

EXPERT OPINION

Primary angioplasty for ST-segment elevation myocardial infarction is a well-established therapeutic option with proven mortality benefits. We suppose that catheter-based interventions for acute stroke will spread quickly from centers of excellence to routine clinical practice. We believe that ongoing research will provide a basis for the expansion of interventional treatment of pulmonary embolism soon.

Outcomes of Catheter-Based Pulmonary Artery Embolectomy in Patients With Sub-Massive to Massive Pulmonary Embolism

Background Pulmonary embolism (PE) is the third leading cause of cardiovascular death after myocardial infarction and stroke. The ideal therapeutic approach for these patients remains undetermined. We report our single-center outcome data for using a catheter-based pulmonary artery thrombectomy using the FlowTriever (Inari Medical, Irvine, CA) device as management for patients with submassive PE. Methods We retrospectively collected data from a single center of patients who underwent thrombectomy using INARI FlowTriever device. The data on baseline characteristics, procedural and clinical outcomes was collected and analysed Results A total of 38 patients with PE treated endovascularly with the FlowTriever device were identified: 33 with submassive PE and five with massive PE. The mean age was 65.9 years (95% CI 61.9 - 69.8), and most patients were male (73.7%). All patients had right heart strain as the main indication for thrombectomy. Four patients (10.53%) required pressor support before the procedure. In 31 patients, pre- and post-thrombectomy average mean pulmonary artery pressure (mPAP) was improved significantly by 22% (p < 0.01). Two patients had significant adverse events at 48 hours (5.26%). One patient experienced procedure-related access site hematoma and life-threatening bleeding, while another developed intraprocedural-related massive hemoptysis and cardiopulmonary arrest. Overall post-procedural length of stay was 7.7 ± 5.6 days; 52.63% of patients (n = 20) required intensive care. Three patients (7.89%) required pressor support before the procedure, and 78.9% of patients (n = 30 of 38) survived hospital discharge. Thirty patients who survived were discharged with oral anticoagulation. There were no device-related complications. Conclusion Randomized trials of interventional devices for submassive PE are warranted to either support or alert the medical community of the safety and efficacy of their use for patients with submassive and massive PE. In time, pulmonary embolism response team (PERT) may generate outcome data that better inform treatment decisions.

Mechanical thrombectomy versus catheter directed thrombolysis in patients with pulmonary embolism: A multicenter experience

OBJECTIVES

Compare in-hospital outcomes of patients treated with either mechanical thrombectomy (MT) or catheter directed lysis (CDL) in treatment of acute pulmonary embolism (PE).

METHODS

This is a multicenter, retrospective cohort study of patients undergoing MT or CDL for acute PE between 2014 and 2021. The primary outcome was the composite of in-hospital death, significant bleed, vascular complication, or need for mechanical support post-procedure. Secondary outcomes included the individual components of the composite outcome in addition to blood transfusions, invasive hemodynamics, echocardiographic data, and intensive care unit (ICU) utilization.

RESULTS

458 patients were treated for PE with 266 patients in the CDL arm and 192 patients in the MT arm. The primary composite endpoint was not significantly different between the two groups with CDL 12% versus MT 11% (p = 0.5). There was a significant difference in total length of ICU time required with more in the CDL group versus MT (3.8 ± 2.0 vs. 2.8 ± 3.0 days, p = 0.009). All other secondary end points showed no significant difference between the groups.

CONCLUSIONS

In patients undergoing catheter directed treatment of PE, there was no difference between MT and CDL in terms of in-hospital mortality, bleeds, catheter-related complications, and hemodynamics.

Comparison of Large-Bore Thrombectomy With Catheter-Directed Thrombolysis for the Treatment of Pulmonary Embolism

Background

There is significant debate on whether large-bore thrombectomy (LBT) or catheter-directed thrombolysis (CDT) is superior for the treatment of intermediate- and high-risk pulmonary embolism (PE) while employing an early invasive strategy through endovascular therapies.

Methods

Between 2018 and 2021, 147 patients who presented to our institution with acute intermediate- or high-risk PE and had undergone PE Response Team-guided endovascular intervention with either LBT (Inari FlowTriever) or CDT (EKOSonic) were retrospectively reviewed. Data on the patients' clinical characteristics, comorbidities, serum biomarkers, hemodynamics, and imaging characteristics were obtained. The primary outcome was all-cause mortality; the secondary outcomes were all-cause readmission, readmission for PE, and length of stay in the intensive care unit and hospital. The safety outcome of procedure-related bleeding was evaluated. Kaplan-Meier curves were used to estimate the cumulative event rate. Multivariate Cox-proportional hazard regression and inverse propensity weighting were used to adjust for confounders.

Results

The median age of the patients was 63 (IQR, 53-73) years, and 48.3% of the patients were women. Patients in the LBT group had a higher PE Severity Index score (LBT vs CDT: median, 132 vs 108; P = .015) and greater prevalence of malignancy (LBT vs CDT: median, 22.7% vs 6%; P = .011). After propensity matching for baseline characteristics, there was no significant difference in all-cause mortality (LBT vs CDT: median, 15.8% vs 9.1%; hazard ratio, 0.64; 95% CI, 0.21-1.98; P = .442) for up to 1 year. The secondary outcomes or safety end points were also similar between the 2 interventions. An exploratory analysis showed elevated PE Severity Index scores, lower systolic blood pressures, and higher lactic acid levels to be associated with an increased risk of early death at 30 days.

Conclusions

In this retrospective cohort study, there was no significant difference in the cumulative event rate of all-cause mortality between LBT and CDT. Further studies are needed to evaluate the use of LBT versus CDT versus noninvasive therapy to understand outcomes and appropriate patient selection among those with intermediate- and high-risk PE.

Mechanical aspiration thrombectomy for the treatment of pulmonary embolism: A systematic review and meta-analysis

INTRODUCTION

There are no randomized trials studying the outcomes of mechanical aspiration thrombectomy (MAT) for management of pulmonary embolism (PE).

METHODS

We performed a systematic review and meta-analysis of existing literature to evaluate the safety and efficacy of MAT in the setting of PE. Inclusion criteria were as follows: studies reporting more than five patients, study involved MAT, and reported clinical outcomes and pulmonary artery pressures. Studies were excluded if they failed to separate thrombectomy data from catheter-directed thrombolysis data. Databases searched include PubMed, EMBASE, Web of Science until April, 2021.

RESULTS

Fourteen case series were identified, consisting of 516 total patients (mean age 58.4 ± 13.6 years). Three studies had only high-risk PE, two studies had only intermediate-risk PE, and the remaining nine studies had a combination of both high-risk and intermediate-risk PE. Six studies used the Inari FlowTriever device, five studies used the Indigo Aspiration system, and the remaining three studies used the Rotarex or Aspirex suction thrombectomy system. Four total studies employed thrombolytics in a patient-specific manner, with seven receiving local lysis and 17 receiving systemic lysis, and 40 receiving both. A random-effects meta-analyses of proportions of in-hospital mortality, major bleeding, technical success, and clinical success were calculated, which yielded estimate pooled percentages [95% CI] of 3.6% [0.7%, 7.9%], 0.5% [0.0%, 1.8%], 97.1% [94.8%, 98.4%], and 90.7% [85.5%, 94.3%].

CONCLUSION

There is significant heterogeneity in clinical, physiologic, and angiographic data in the currently available data on MAT. RCTs with consistent parameters and outcomes measures are still needed.

FlowTriever Retrieval System for the treatment of pulmonary embolism: overview of its safety and efficacy

INTRODUCTION

Pulmonary embolism (PE) is the third leading cause of cardiovascular mortality. There has been little change in PE mortality rates over the past two decades making this an appealing area for innovation and development.

AREAS COVERED

While anticoagulation (AC) and systemic thrombolysis (ST) are the mainstay treatments for high-risk PE and intermediate-high-risk PE with decompensation, advancements in catheter- based therapies offer potential alternatives. Areas covered here will include present guidelines for PE treatment and the landscape of catheter-directed therapies with a focus on the FlowTriever (FT) Retrieval System. Available safety and efficacy data will be reviewed. An online search via Google Scholar and PubMed with the keywords INARI Flowtriever, venous thromboembolism, and pulmonary embolism, alongside bibliographies of published articles, was undertaken as a review of the literature on the FlowTriever system for this device overview.

EXPERT OPINION

The five-year outlook on the role of catheter-directed therapies in the management of PE includes continued innovation in catheter-directed therapies and a number of high-quality trials on the horizon.

Temporal Analysis of Tachycardia During Catheter Directed Thrombolysis for Acute Pulmonary Embolism

PURPOSE

To evaluate the effect of catheter directed thrombolysis (CDT) on heart rate (HR) in patients with sinus tachycardia and acute pulmonary embolism (PE).

METHODS

A retrospective chart review was performed for patients who underwent CDT with tPA for acute massive or submassive PE between 12/2009 and 2/2020. Included were patients who presented with tachycardia at the time of initiation of CDT. Patients with chronic PE, atrial fibrillation, beta blocker therapy, adjunctive endovascular therapy, systemic thrombolysis, or who expired before conclusion of CDT were excluded. HR was measured approximately every hour during CDT. Graphs were plotted of HR as a function of CDT duration. Two interventional radiologists identified the point of plateau (POP) on the graph where CDT had maximized its benefit in decreasing the patient's HR. Discrepancies were adjudicated by a third interventional radiologist and the median of the 3 measurements was selected. The primary endpoint was the duration of CDT from initiation until the POP.

RESULTS

48 patients were included (52.5 ± 14.7 years, 56.3% female). The POP occurred after 13.1 ± 6.1 hours, by which point HR had been reduced from 110 ± 9.2 bpm to 88 ± 10.6 bpm. Sinus tachycardia was not resolved in 10 patients even though they achieved maximal improvement in HR after 11.3 ± 6.7 hours.

CONCLUSION

Patients presenting with sinus tachycardia related to acute PE achieved maximal, sustained reduction in heart rate from CDT, after approximately 13 hours of infusion. Patients who did not resolve their tachycardia by that point in time were unlikely to resolve it by the conclusion of CDT.