Ultrasound-accelerated Thrombolysis Research Articles

Urokinase versus Alteplase in Patients with Intermediate-High-Risk Pulmonary Embolism Treated with Ultrasound-Accelerated Endovascular Thrombolysis.

Ultrasound-accelerated thrombolysis (USAT) is a safe and effective treatment for patients with intermediate-high-risk pulmonary embolism (PE). In all studies investigating USAT in the setting of PE, the recombinant tissue-plasminogen activator (rt-PA) alteplase or actilyse was used. Currently, there is a shortage of alteplase (Alteplase, Boehringer Ingelheim) in Europe. It is unknown whether the efficacy of urokinase (UK) is comparable with alteplase for USAT in patients with PE. Patients with intermediate-high-risk PE undergoing USAT with urokinase and alteplase were included in this study. One-to-one nearest neighbour matching was performed to account for baseline differences. We identified one patient treated with USAT and UK (n = 9) for each patient treated with USAT and alteplase (n = 9). A total of 56 patients underwent USAT. The treatment was successful in all patients. The propensity score matched the identified nine pairs of patients. There were no statistically significant differences in the change in right ventricle-to-left ventricle (RV/LV) ratio (0.4 ± 0.3 versus 0.5 ± 0.4, p = 0.54), systolic pulmonary artery pressure (17.3 ± 8.0 versus 18.1 ± 8.1, p = 0.17), or improvement of RV function (5.8 ± 3.8 versus 5.1 ± 2.6, p = 1.0). The complication rates were comparable (11% in both groups, p = 0.55). There were no deaths in hospital or during 90 days in either group. In this case-matched comparison, the short-term clinical and echocardiographic outcomes showed comparable results between USAT-UK and USAT-rt-PA.

The Safety and Efficacy of Ultrasound-Accelerated Catheter-Directed Thrombolysis in Patients with Intermediate-High-Risk Pulmonary Embolism: Bo-NE-Experience.

Ultrasound-accelerated thrombolysis (USAT) is an advanced interventional therapy for patients with intermediate-high-risk pulmonary embolism (PE) who deteriorated on anticoagulation or for high-risk patients for whom systemic thrombolysis is contraindicated. The aim of this study is to investigate the safety and efficacy of this therapy with a focus on the improvement of vital signs and laboratory parameters. Seventy-nine patients with intermediate-high-risk PE were treated with USAT from August 2020 to November 2022. The therapy significantly decreased the mean RV/LV ratio from 1.2 ± 0.22 to 0.9 ± 0.2 (p < 0.001) as well as the mean PAPs from 48.6 ± 11 to 30.1 ± 9.0 mmHg (p < 0.001). The respiratory and heart rate decreased significantly (p < 0.001). Serum creatinine decreased significantly from 1.0 ± 0.35 to 0.9 ± 0.3 (p < 0.001). There were 12 access-associated complications, which could be treated conservatively. One patient had haemothorax after the therapy and had to be operated on. USAT is an effective therapy for patients with intermediate-high-risk PE, with favourable hemodynamic, clinical, and laboratory outcomes.

Fixed-dose ultrasound-accelerated thrombolysis for acute pulmonary embolism: short- and long-term outcome data from a single-center study

Abstract Funding Acknowledgements Type of funding sources: None. Background Data on clinical outcomes after fixed-dosed ultrasound-accelerated thrombolysis (USAT) for acute pulmonary embolism (PE) is still limited, particularly concerning safety and long-term course. Methods We studied patients with acute PE treated with USAT at a University Hospital between 2018 and 2022. Patients were candidates to USAT if acute PE fulfilled the criteria of high-risk or intermediate-high risk (plus additional markers of clinical severity or early deterioration) as per European guidelines. USAT was given at a standard regimen of 10 mg alteplase/catheter over 15 hours. Early outcomes included: mean pulmonary arterial pressure (mPAP) before and after treatment, National Early Warning Score (NEWS) during USAT; 30-day all-cause death, 30-day hemodynamic decompensation, 30-day PE recurrence, and 30-day major bleeding complications (ISTH definition). Late outcomes were: confirmed CTEPH, persistent post-PE dyspnea, and "post-PE impairment" (PPEI), as defined by the combination of dyspnea with sPAP&amp;gt;35 mm Hg, TAPSE &amp;lt;1.6cm, or RV/RA gradient &amp;gt;36 mmHg, death. Results We included 161 patients: the mean age was 67.8 (SD 14.6) years and 96 were men. All had acute bilateral PE and were treated with two catheters for a median alteplase dose of 20 mg. All patients received anti-Xa activity-adjusted unfractionated heparin, except one, who received argatroban. mPAP decreased from a mean of 35.6 (SD 9.8) to 25.6 (SD 8.2) mmHg after a 15-hour course of treatment (absolute difference 10.2 mmHg; SD 8.1). The NEWS decreased from a median of 5 (Q1-Q3: 4-6) points before USAT to 3 (Q1-Q3: 2-4) points after USAT. No hemodynamic decompensations were recorded within 30 days of hospitalization. One (0.6%) recurrence of PE within 30 days occurred. Two major bleeding (1.2%), of which one (0.6%) was intracranial and fatal, were observed. No other deaths were recorded within 30 days of acute PE. Of 125 patients followed at our center and included in the long-term analysis (median follow-up time 104, Q1-Q3 91-200, days), CTEPH was diagnosed in 2 (1.6%) patients. In one patient, CTEPH was most probably pre-existing, namely present already at the time of "acute" PE, based on hemodynamic and radiological findings. CTEPH was incident in the other patient. 24 (19.2%) patients reported persistent dyspnea, of whom 5 (4.0%) fulfilled the PPEI criteria. Death was recorded in 8 (6.4%) patients after a median of 591 (Q1-Q3; 517-710) days and no event was PE-related. One (0.8%) recurrent PE occurred. Conclusions USAT rapidly reduced the mean pulmonary arterial pressure in selected intermediate-high and high-risk acute PE with a good safety profile. Only 4.0% patients had residual symptoms and right ventricular dysfunction over long-term follow-up. This data reassures USAT being an effective and safe option for acute PE also in terms of long-term outcomes.

EKOSTM in Octogenarians: The Safety and Efficacy of Ultrasound-Accelerated Catheter-Directed Thrombolysis in Elderly Patients with Intermediate-High-Risk Pulmonary Embolism.

Pulmonary embolism (PE) is a common cardiovascular disease. Elderly patients with acute PE have very high mortality rates. Data concerning the safety and effectiveness of ultrasound-accelerated thrombolysis (USAT) in this age group are lacking. Nineteen octogenarians with acute pulmonary embolism underwent USAT between August 2020 and February 2023 at two centres in Germany and were retrospectively analysed. The main efficacy measures were the right ventricle to left ventricle diameter (RV/LV) ratio, systolic right ventricle function, and invasive and echocardiographic measured systolic pulmonary artery pressure (sPAP). The main safety measures were in-hospital death and the bleeding rate according to the GUSTO bleeding score. USAT was associated with an improved RV/LV ratio (0.36 ± 0.29, p < 0.001), systolic right ventricle function (5.0 ± 3.8, p < 0.001), and systolic pulmonary artery pressure (sPAP) at 24 h after therapy (24.2 ± 11.2 mmHg and 19 ± 13.4 mmHg, p < 0.001). No in-hospital deaths or bleeding complications occurred. USAT with EKOSTM may be a safe and effective therapeutic option for octogenarians with acute pulmonary embolism.

INTRACEREBRAL HEMORRHAGE POSTPHARMACOMECHANICAL CATHETER-DIRECTED THROMBOLYSIS: CAN WE PREVENT IT?

INTRACEREBRAL HEMORRHAGE POSTPHARMACOMECHANICAL CATHETER-DIRECTED THROMBOLYSIS: CAN WE PREVENT IT?

Utilization of EKOS (Ultrasound-Accelerated Thrombolysis) in the Treatment of Acute Limb Ischemia: One-Year Outcome Follow-Up

Utilization of EKOS (Ultrasound-Accelerated Thrombolysis) in the Treatment of Acute Limb Ischemia: One-Year Outcome Follow-Up

Abstract No. 274 Cost analysis of ultrasound-enhanced catheter use in the treatment of pulmonary embolism

Pulmonary embolism (PE) is a common form of venous thromboembolism, which causes around 300,000-600,000 deaths every year in the US. Currently, there are a variety of methods to treat pulmonary embolism, including pharmacological, procedural, and surgical interventions. With the emergence of novel technology, physicians are able to utilize techniques such as catheter-directed thrombolysis (CDT) and ultrasound-accelerated thrombolysis (USAT) to treat PE. While literature exists on the safety and efficacy of CDT and USAT, little research has been published on the cost-effectiveness of the two interventions.

Percutaneous thrombectomy or ultrasound-accelerated thrombolysis for initial management of acute limb ischaemia.

Acute limb ischaemia (ALI), the sudden and significant reduction of blood flow to the limb,is considered a vascular emergency. In the general population, the incidence is estimated as 14 per 100,000. Prognosis depends on the time it takes to diagnose the condition and begin appropriate treatment. Standard initial interventional treatments include conventional open surgery and endovascular interventions such as catheter-directed thrombolysis (CDT). Percutaneous interventions, such as percutaneous thrombectomy (PT, including mechanical thrombectomy or pharmomechanical thrombectomy) and ultrasound-accelerated thrombolysis (USAT), are also performed as alternative endovascular techniques. The proposed advantages of PT and USAT include reduced time to revascularisation and when combined with catheter-directed thrombolysis, a reduction in dose of thrombolytic agents and infusion time. The benefits of PT or USAT versus open surgery or thrombolysis alone are still uncertain. In this review, we compared PT or USAT against standard treatment for ALI, in an attempt to determine if any technique is comparatively safer and more effective. To assess the safety and effectiveness of percutaneous thrombectomy or ultrasound-accelerated thrombolysis for the initial management of acute limb ischaemia in adults. The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, the World Health Organization (WHO) International Clinical Trials Registry Platform, and ClinicalTrials.gov to 3 March 2021. We searched reference lists of relevant studies and papers. We included randomised controlled trials (RCTs) that compared PT (any modality, including mechanical thrombectomy (aspiration, rheolysis, rotation) or pharmomechanical thrombectomy) or USAT with open surgery, thrombolysis alone, no treatment, or another PT modality for the treatment of ALI. Two review authors independently selected the studies, assessed risk of bias, extracted data, performed data analysis, and assessed the certainty of evidence according to GRADE. Outcomes of interest were primary patency, amputation rate, major bleeding, clinical success, secondary patency, and adverse effects. We included one RCT in this review. This study had a total of 60 participants and compared USAT with standard treatment (CDT). The study included 32 participants in the CDT group and 28 participants in the USAT group. We found no evidence of a difference between USAT and CDT alone for the following evaluated outcomes: amputation rate (risk ratio (RR) 1.14, 95% confidence interval (CI) 0.17 to 7.59); major bleeding (RR 1.71, 95% CI 0.31 to 9.53); clinical success (RR 1.00, 95% CI 0.94 to 1.07); and adverse effects (RR 5.69, 95% CI 0.28 to 113.72). We rated the certainty of the evidence as very low for these outcomes. We downgraded the certainty of the evidence for amputation rate, major bleeding, clinical success, and adverse effects by two levels due to serious limitations in the design (there was a high risk of bias in critical domains) and by two further levels due to imprecision (a small number of participants and only one study included). The study authors reported 30-day patency, but did not report primary and secondary patency separately. The patency rate in the successfully lysed participants was 71% (15/21) in the USAT group and 82% (22/27)in the CDT group. The study authorsdid not directly report secondary patency, which is patency after secondary procedures, but they did report on secondary procedures. Secondary procedures were subdivided into embolectomy and bypass grafting. Embolectomy was performed on 14% (4/28) of participants in the USAT group versus 3% (1/32) of participants in the CDT group. Bypass grafting was performed on 4% (1/28) of participants in the USAT group versus 0% in the CDT group. As we did not have access to the specific participant data, it was not possible to assess these outcomes further. We did not identify studies comparing the other planned interventions. There is insufficient evidence to assess the safety and effectiveness of USAT versus CDT alone for ALI for our evaluated outcomes: amputation rate, major bleeding, clinical success, and adverse effects. Primary and secondary patency were not reported separately. There was no RCT evidence for PT. Limitations of this systematic review derive from the single included study, small sample size, short clinical follow-up period, and high risk of bias in critical domains. For this reason, the applicability of the results is limited. There is a need for high-quality studies to compare PT or USAT against open surgery, thrombolysis alone, no treatment, or other PT modalities for ALI. Future trials should assess outcomes, such as primary patency, amputation rate, major bleeding, clinical success, secondary patency, and adverse effects.

Abstract 14165: Ultrasound-Accelerated Thrombolysis May Be the Preferred Catheter-Based Lytic Therapy for Pulmonary Embolism

Introduction: Pulmonary embolism (PE) is estimated to cause 100,000 deaths annually in the US. Systemic use of fibrinolytic drugs carries risks of significant bleeding. Catheter directed thrombolysis (CDT) delivers thrombolytic drugs directly to the site of the clot and in lower doses which may improve its safety profile. We aimed to investigate the safety and efficacy of CDT in intermediate risk PE and contemporary trends of follow-up cardiac testing in these patients. Methods: 75 patients who underwent CDT for intermediate risk PE at a single center from 2014-2021 were studied retrospectively. Outcomes included procedure related complications and mortality. Continuous variables are presented as mean±SD, categorical variables as percentages. Logistic regression and survival analysis was used. Data was analyzed in Stata/BE 17.0. Results: Demographics (Table 1), lab and imaging data (Table 2) were assessed for 75 patients. Troponin and BNP were elevated in 63.5% and 60% respectively. RV dilation was present in 86.7%. Ultrasound accelerated thrombolysis (EKOS) was performed in 80% and standard CDT in 20%. One procedural complication occurred, a patient undergoing standard CDT suffered a cardiac arrest and died. Major bleeding occurred in four patients but did not contribute to mortality. Mortality at 30 days and one year were 6.8% (5/73) and 13% (9/69) respectively. Only three deaths were attributed to cardiovascular causes. Those who underwent EKOS had 85.6% lower odds of death in 30 days (OR 0.14 (0.03-0.79), p=0.02) compared to CDT; however, our results are limited by a small sample size. Follow up imaging was assessed at 1 year (Table 3). Echo was most frequently performed in 45.3% of patients. Conclusions: EKOS for intermediate risk PE is a safe procedure with no procedural mortalities in our study. As follow up was poor, with less than 50% of the cohort receiving imaging, future directions should be aimed at ensuring these patients are monitored for long-term sequelae of PE.

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

IntroductionTreatment 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 presentationWe 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.ConclusionCurrent 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.

Utilization of Ultrasound-Accelerated Thrombolysis in the Treatment of Acute Limb Ischemia in Patients With Failed Restoration of Flow With Initial Thrombectomy

Many persons with opioid use disorder (OUD) initiate medication for opioid use disorder (MOUD) with one clinic and switch to another clinic during their course of treatment. These switches may occur for referrals or for unplanned reasons. It is unknown, however, what effect switching MOUD clinics has on continuity of MOUD treatment or on overdoses.To examine patterns of switching MOUD clinics and its association with the proportion of days covered (PDC) by MOUD, and opioid-related overdose.Cross-sectional retrospective analysis of Pennsylvania Medicaid claims data.MOUD clinic switches (i.e., filling a MOUD prescription from a prescriber located in a different clinic than the previous prescriber), PDC, and opioid-related overdose.Among 14,107 enrollees, 43.2 % switched clinics for MOUD at least once during the 270 day period. In multivariate regression results, enrollees who were Non-Hispanic black (IRR = 1.43; 95 % CI = 1.24–1.65; p < 0.001), had previous methadone use (IRR = 1.32; 95 % CI = 1.13–1.55; p < 0.001), and a higher total number of office visits (IRR = 1.01; CI = 1.01−1.01; p < 0.001) had more switches. The number of clinic switches was positively associated with PDC (OR = 1.12; 95 % CI = 1.10–1.13). In secondary analyses, we found that switches for only one MOUD fill were associated with lower PDC (OR = 0.97; 95 % CI = 0.95−0.99), while switches for more than one MOUD fill were associated with higher PDC (OR = 1.40; 95 % CI = 1.36–1.44). We did not observe a relationship between opioid-related overdose and clinic switches.Lack of prescriber continuity for receiving MOUD may not be problematic as it is for other conditions, insofar as it is related to overdose and PDC.

Comparison of ultrasound-accelerated versus conventional catheter-directed thrombolysis for deep vein thrombosis: A systematic review and meta-analysis.

Recent in vitro and clinical studies have shown that ultrasound-accelerated catheter-directed thrombolysis (USACDT) can accelerate thrombolysis. Therefore, in this meta-analysis, we aimed to compare the efficacy and safety of USACDT with conventional catheter-directed thrombolysis in patients with deep vein thrombosis. A systematic search of the following electronic databases was performed from their dates of inception to 20 June 2020: MEDLINE, Scopus, Google Scholar, CINAHL, Cochrane Library, and EMBASE. All randomized controlled trials that directly compared the complications and efficacy of USACDT and conventional catheter-directed thrombolysis in patients with deep vein thrombosis were identified. The statistical analysis was performed using comprehensive meta-analysis software. Finally, 18 studies with a total of 597 participants were included in our meta-analysis according to the eligibility criteria. Pooled proportion of USACDT success in patients with deep vein thrombosis was 87.8% (18 studies; 95% CI: 83.1-91.3). Success rate was significantly higher in USACDT treatment than in conventional catheter-directed thrombolysis treatment (seven studies; OR: 2.96; 95% CI: 1.69-5.16; P < 0.01)). Although the mean infusion time was higher in catheter-directed thrombolysis treatment compared to USACDT treatment, this difference was not statistically significant (three studies; MD: -1.46; 95% CI: -3.25-0.32; P = 0.10). Moreover, pooled rate of complications was lower in USACDT than catheter-directed thrombolysis which was not statistically significant (seven studies; OR: 0.49; 95% CI: 0.13-1.76; P = 0.27). This meta-analysis revealed that USACDT significantly increased the success rate of thrombolysis compared to conventional catheter-directed thrombolysis. Furthermore, USACDT was associated with lower rate of complication and infusion time. Taken together, these findings confirm the superiority of this novel intervention over conventional catheter-directed thrombolysis in treatment of patients with deep vein thrombosis.

Evidence-Based Management of a Patient With an EKOS Catheter.

Q: What are the evidence-based recommendations for nursing management of a patient with an EKOS catheter?A: Sara Knippa, MS, RN, ACCNS-AG, CCRN, PCCN, and Shannon Vernon, BSN, RN, CCRN, reply:Catheter-directed thrombolysis (CDT) is a targeted alternative to systemic thrombolysis. It can be used for patients experiencing thrombotic problems such as deep vein thrombosis, pulmonary embolism, and peripheral arterial occlusion. In CDT, an infusion catheter is inserted into the artery or vein through a sheath and guided to the site of the thrombus. A thrombolytic agent, often alteplase, is continually infused through the catheter directly to the clot for a particular amount of time.1Therapy using an EKOS catheter, as part of the EkoSonic Endovascular System (Boston Scientific), takes CDT a step further by adding intravessel ultrasound. The EkoSonic Endovascular System (EKOS) consists of a specialized catheter (see Figure) and a control unit. The catheter delivers small ultrasound waves, which assist the thrombolytic medication to dissolve the clot.2 The technique of applying ultrasound waves while administering a thrombolytic medication is called ultrasound-assisted or ultrasound-accelerated thrombolysis (USAT); the EKOS equipment is prominently used for USAT.1Some question remains regarding the benefit of USAT compared with that of CDT in various clinical situations. The intended benefit of the ultrasound waves is to dissolve the clot faster or to require a lower dose of the thrombolytic drug, thereby decreasing the risk of bleeding and other complications. Most USAT systems, however, are more expensive than CDT. Does the extra expense translate into improved clinical outcomes? Some initial support exists for the clinical benefit of USAT in patients with arterial thromboembolic disease3 and deep vein thrombosis,4 but more evidence is needed. Recent studies suggest that CDT and USAT are not significantly different in patients with pulmonary embolism.5,6 Until definitive data are available, nurses may use both USAT and CDT in clinical practice.Very little definitive information is available to provide an evidence-based approach to nursing care for patients receiving thrombolytic therapy in conjunction with USAT.1 Therefore, from a nursing perspective, the best approach is to understand how a USAT system functions and how to troubleshoot any problems, and to focus on the most common complications that occur with any thrombolytic drug. These steps will allow nurses to appropriately target assessments and interventions.Nurses should be familiar with the USAT system that their organization uses. The ultrasound therapy must be running in order for the system to be effective. For example, with the EKOS system, the ultrasound should not run without infusions instilling through both lumens of the catheter (see Figure): the thrombolytic agent infuses through the drug lumen, and normal or heparinized saline infuses through the coolant lumen. The thrombolytic infusion does not stop, regardless of the status of the ultrasound. The ultrasound can be paused when necessary (eg, for Doppler assessment, during ultrasound diagnostic tests), but otherwise the nurse should verify that the ultrasound is running at all times; to do so, one can look for the blinking yellow light on the console.7,8Complications may stem from vascular access, thrombolytic drug administration, and contrast used for imaging. The EKOS catheter and sheath can be removed at the bedside or in a procedural area. Staff who can remove the catheter and sheath should receive specific training in this process. In addition, an inferior vena cava filter may need to be placed after removal of the catheter and sheath in order to reduce the patient’s risk of pulmonary embolism.7Manufacturer recommendations provide a stable starting point for the development of facility-specific guidelines for the care of patients receiving USAT. Additional strategies that may be helpful when evidence-based guidelines are not available include reaching out to other facilities who are using the equipment, reaching out to national organizations, and working with a hospital or unit-based practice committee to create a facility-specific guideline or resource.Because patients requiring this therapy may be infrequent, facilities would benefit from creating relevant resources that nurses can reference quickly at the point of care.9 When specific evidence-based guidelines are not available, nurses can use their existing, related knowledge to anticipate complications and provide safe care.

Evaluation of Fibrinogen Levels during Catheter-Directed Thrombolysis for Acute Pulmonary Embolism

PurposeTo evaluate the effect of catheter-directed thrombolysis (CDT) with tissue plasminogen activator (tPA) on plasma fibrinogen levels (PFLs) in the setting of acute pulmonary embolism (PE) and the relationship between PFL and hemorrhagic complications. Materials and MethodsA retrospective review of CDT procedures between 2009 and 2019 identified 147 CDT procedures for massive or submassive PE (55.8% males; age, 56.5 ± 14.8 years; 90.5% submassive). All patients received therapeutic anticoagulation during CDT with unfractionated heparin (UFH) (69.4%) or low-molecular-weight heparin (LMWH, 30.6%) infusion. CDT was performed with ultrasound-accelerated thrombolysis (USAT) catheters (n = 98), conventional catheter-directed thrombolysis (CCDT) catheters (n = 34), or a combination of both (n = 15). ResultsThere was a decrease (P = .007) of 15.1 ± 69.4 mg/dl from the initial PFL (376.1 ± 122.7 mg/dl) to the final PFL (361 ± 118.7 mg/dl), which was measured after a mean of 24.1 ± 11.7 hours with a mean tPA dose of 28.3 ± 14.2 mg. The fibrinogen nadir was 327.6 ± 107.1 mg/dl measured 13.4 ± 10.3 hours after initiation of thrombolysis. Of patients with hemorrhagic complications (n = 6), initial, final, and nadir PFL were not significantly lower (P = .053, P = .081, and P = .086, respectively) than the remainder of the cohort. No significant difference was noted in initial and final PFL between the LMWH and UFH groups (P = .2 and P = .1, respectively) or between the CCDT and USAT groups (P = .5 and P = .9, respectively). The UFH group had a lower nadir PFL than the LMWH group (P = .03). ConclusionsDespite a significant drop in PFL during CDT for acute PE, this was not associated with hemorrhagic complications. These findings were not affected by the choice of anticoagulant or catheter delivery system.

Relationship of left ventricular outflow tract velocity time integral to treatment strategy in submassive and massive pulmonary embolism.

Pulmonary embolism is associated with high rates of mortality and morbidity. It is important to understand direct comparisons of current interventions to differentiate favorable outcomes and complications. The objective of this study was to compare ultrasound-accelerated thrombolysis versus systemic thrombolysis versus anticoagulation alone and their effect on left ventricular outflow tract velocity time integral. This was a retrospective cohort study of subjects ≥18 years of age with a diagnosis of submassive or massive pulmonary embolism. The primary outcome was the percent change in left ventricular outflow tract velocity time integral between pre- and post-treatment echocardiograms. Ultrasound-accelerated thrombolysis compared to anticoagulation had a greater improvement in left ventricular outflow tract velocity time integral, measured by percent change. No significant change was noted between the ultrasound-accelerated thrombolysis and systemic thrombolysis nor systemic thrombolysis and anticoagulation groups. Pulmonary artery systolic pressure only showed a significant reduction in the ultrasound-accelerated thrombolysis versus anticoagulation group. The percent change of right ventricular to left ventricular ratios was improved when systemic thrombolysis was compared to both ultrasound-accelerated thrombolysis and anticoagulation. In this retrospective study of submassive or massive pulmonary embolisms, left ventricular outflow tract velocity time integral demonstrated greater improvement in patients treated with ultrasound-accelerated thrombolysis as compared to anticoagulation alone, a finding not seen with systemic thrombolysis. While this improvement in left ventricular outflow tract velocity time integral parallels the trend seen in mortality outcomes across the three groups, it only correlates with changes seen in pulmonary artery systolic pressure, not in other markers of echocardiographic right ventricular dysfunction (tricuspid annular plane systolic excursion and right ventricular to left ventricular ratios). Changes in left ventricular outflow tract velocity time integral, rather than echocardiographic markers of right ventricular dysfunction, may be considered a more useful prognostic marker of both dysfunction and improvement after reperfusion therapy.

Analysis of pulmonary embolism patients treated with EkoSonic™ endovascular system.

The aim of this study was to evaluate the efficacy and the safety of the EkoSonic™ endovascular system applications in patients hospitalized with the diagnosis of intermediate-high-risk pulmonary embolism. Between January 2018 and March 2019, a total of 15 patients (7 males, 8 females; mean age 64.7±17.8 years, range, 35 to 90 years) who underwent ultrasound-accelerated thrombolysis using the EkoSonic™ endovascular system for pulmonary embolism were retrospectively analyzed. The diagnosis of pulmonary embolism was made based on pulmonary computed tomography angiography. All patients were evaluated by echocardiography for right ventricular dysfunction and serum levels of troponin I and brain natriuretic peptide were recorded. The mean arterial blood gas oxygen saturation values of the patients before and after the procedure were 86.3±3.5% and 94.2±2.5%, respectively, indicating a statistically significant difference (p=0.001). The mean partial oxygen pressure values before and after the procedure were 73.3±7.7 mmHg and 90.7±5.0 mmHg, respectively, indicating a statistically significant difference (p=0.001). There was also a statistically significant difference in the mean right ventricular diameter before and after the procedure (p=0.001). The mean pre- and post-procedural pulmonary arterial pressure was 44±7.1 mmHg and 36.3±4.5 mmHg, respectively, indicating a statistically significant difference (p=0.001). Of the patients, 93.7% were free from post-procedural complications. The EkoSonic™ endovascular system improved right ventricular dysfunction, decreased pulmonary arterial pressure, and improved oxygenation in patients with intermediate-high-risk pulmonary embolism without increasing the risk for bleeding.

Role of Interventional Radiologist in the Management of Acute Pulmonary Embolism.

Pulmonary embolism is a common cause of morbidity and mortality which continues to increase in overall incidence. Because it can occur with a wide range of clinical presentations, different guidelines have been developed for appropriate risk stratification of patients; interventional radiology plays a vital role in the management of both massive and submassive pulmonary embolism. Catheter-directed therapy, including mechanical and aspiration thrombectomy, standard catheter-directed thrombolysis, and ultrasound-accelerated thrombolysis, has many benefits, including lower thrombolytic doses and intraclot administration of thrombolytic therapy. While the role of catheter-directed therapy is still being developed, four important prospective studies have demonstrated its safety and efficacy. Additional studies comparing short- and long-term clinical outcomes in patients treated with catheter-directed therapy versus anticoagulation are the next step in understanding its role within the management of submassive pulmonary embolism. Furthermore, multidisciplinary pulmonary embolism response teams, in which interventional radiology plays a crucial role, are becoming essential to appropriately managing pulmonary embolism patients, including selection of those who may benefit from catheter-directed therapy.

Abstract No. 677 Reduced right heart dysfunction following pulmonary embolism treated with catheter-directed therapy: a retrospective study

A pulmonary embolism (PE) is a form of venous thromboembolism in the pulmonary vasculature that can have severe manifestations, including pulmonary arterial hypertension. Right ventricular (RV) failure is the most common cause of death in these patients. Patients receive catheter-directed therapy (CDT) if fibrinolysis is contraindicated. Common CDTs include aspiration thrombectomy and ultrasound-accelerated thrombolysis while delivering thrombolytic infusion. The benefit on right ventricular dysfunction (RVD) is not well studied, and needs to be researched further. The purpose of this institutional retrospective study is to quantify the reduction in RVD using several variables found on pre-and-postintervention echocardiograms. An institutional chart review found 44 subjects, of which 26 subjects had both pre- and-post procedure echocardiograms. The rest were lost to follow-up, except for 3 subjects who died due to hemodynamic decompensation. The 26 subjects’ echocardiograms were compared on the following variables of RVD: tricuspid annular plane systolic excursion (TAPSE), RV end-diastolic to Left Ventricular end-diastolic volume ratio (RVd/LVd), Tricuspid Regurgitation (TR) gradient, and RV systolic pressure (RVSP). Upon measurement of the variables before and after the CDT, there was an improvement in TAPSE from 1.42 cm to 1.98 cm (P = 0.0043). RVd/LVd decreased from 0.96 to 0.75 (P = <0.0001). The mean TR gradient decreased from 31.8mm Hg to 22.66 mm Hg (P = 0.062). Lastly, the RVSP decreased from 43.97mm Hg to 35.53mm Hg (P = 0.3223). No severe or moderate bleeds, and no hemorrhagic strokes were experienced. A TAPSE of less than 1.8 cm has a greater RVD, and a greater RV to LV diastolic ratio. While a TAPSE of more than 1.8 cm has a greater 2 year survival. As seen in results, using CDTs gives a favorable outcome in improvement of TAPSE and thus improving RVD. The ULTIMA trial showed RVd/LVd ratio reduced by 0.3 with CDT, while heparinization only had a reduction of 0.03. SEATTLE II also showed similar outcomes. This further advances CDT as an effective option in reducing RVD, thus minimizing the development of chronic thromboembolic pulmonary hypertension in the future.

Preservation of Cardiopulmonary Function in Patients Treated with Ultrasound-Accelerated Thrombolysis in the Setting of Submassive Pulmonary Embolism

PurposeTo evaluate the clinical effectiveness of ultrasound-assisted thrombolysis (USAT) in resolution of right ventricular dysfunction (RVD), preservation of cardiopulmonary function, and quality of life (QoL) in patients with acute submassive pulmonary embolism (PE). Materials and MethodsA single-center prospective study of patients presenting with acute PE and signs of RVD, as determined by right ventricle-to-left ventricle diameter ratio (RV:LV) > 0.9 on computed tomographic angiography of the thorax, was performed. Patients underwent USAT with recombinant tissue plasminogen activator. Primary endpoints measured were RV:LV by echocardiogram at baseline presentation and at 72 hours and 90 days after treatment. Secondary endpoints were QoL scores assessed by SF-36 Health Surveys at baseline and at 90 days, cardiopulmonary exercise test (CPET) parameters at 90 days, and procedural outcomes, including response of pulmonary artery pressure (PAP) and procedural complications. ResultsTwenty-five patients were treated between June 17, 2013, and September 15, 2014, with mean reduction of RV:LV by echocardiogram from 1.38 ± 0.28 at presentation to 0.92 ± 0.14 (P < .0001) at 72 hours and 0.84 ± 0.25 (P < .0001) at 90 days. SF-36 Health Survey scores demonstrated no long-term self-perceived adverse physical or mental effects as a result of PE. CPET parameters, including VO2max, weight-adjusted VO2, VE/VCO2, and VD/VT demonstrated no pulmonary vascular impairment at 90 days. PAP significantly improved after USAT, with mean initial systolic pressure of 50.46 ± 13.98 mmHg reduced to 39.64 ± 8.66 mmHg (P = .0001). There were no deaths, recurrent venous thromboembolism, hemodynamic decompensation, or hemorrhage. ConclusionsUSAT resulted in significant reduction of RV:LV at 72 hours, which was preserved at 90 days. QoL and objective measures of cardiopulmonary function are preserved at 90 days in this population. Further studies with long-term follow-up are needed to determine the potential value of USAT for the prevention of post-PE syndrome in patients with submassive PE.

Catheter-directed therapy for acute pulmonary embolism in children.

Acute pulmonary embolism is a life-threatening condition and rarely occurs in children. In adults, catheter-directed therapy emerges as a potentially safer and effective therapeutic option. However, there is a paucity of data on the safety and efficacy of catheter-directed therapy for pulmonary embolism in children. We report a single-centred experience of catheter-directed therapy for acute pulmonary embolism in children. This is a retrospective study of children who had no CHD and underwent catheter-directed therapy at Detroit Medical Center during a 12-year period from 2005 to 2017. Demographic and clinical data associated with pulmonary embolism were collected along with the outcome. A total of nine patients of median age 16 years with the range from 12 to 20 received catheter-directed therapy for sub-massive (n = 6) and massive pulmonary embolism (n = 3). Among nine patients, one patient received Angiojet thrombectomy and balloon angioplasty, whereas eight patients received catheter-directed thrombolysis using tissue plasminogen activator through infusion catheters (n = 3) or EkoSonic ultrasound-accelerated thrombolysis system (n = 5). In four out of five patients treated with EkoSonic, significant clinical improvement was noticed within 24 hours. Among seven patients who survived, two patients had minor gastrointestinal bleeding with median hospital stay of 8 days with the range from 5 to 24 days, and two patients with massive pulmonary embolism died possibly due to delayed institution of catheter-directed therapy. Catheter-directed therapy with/without EkoSonic is an emerging alternative therapy for sub-massive and massive pulmonary embolism in children. A timely institution of catheter-directed therapy appeared important to improve the outcome.