Catheter Interventions for Pulmonary Embolism: Are They Really that Safe?

[Ultrasound-accelerated thrombolysis. Initial experience in patients with contraindications to systemic thrombolysis]

Background

acute pulmonary embolism (APE) is a complex and potentially deadly entity, with a variable clinical course, considered the third cardiovascular cause of death. Its management varies according to the stratified risk from anticoagulation to reperfusion therapy, suggesting systemic thrombolysis as a first-choice strategy; however, in a large group of patients their use will be contraindicated, discouraged or will have failed, thus recommending as options in such cases endovascular therapies or surgical embolectomy. With the presentation of 3 clinical cases and a review of the literature, we seek to communicate our initial experience in the use of ultrasound-accelerated thrombolysis with the EKOS system and to investigate key elements for its understanding and application.

Clinical cases

the cases of 3 patients with APE of high and intermediate risk with contraindications for systemic thrombolysis taken to accelerated thrombolysis therapy by ultrasound are discussed. They presented adequate clinical and hemodynamic evolution in the short term, achieving a rapid decrease in thrombolysis, systolic and mean pulmonary arterial pressure, improvement of right ventricular function and reduction of thrombotic burden.

Conclusion

Ultrasound-accelerated thrombolysis is a novel pharmaco-mechanical therapy that combines the emission of ultrasonic waves with the infusion of a local thrombolytic agent, a strategy that, according to different trials and clinical registries, has a high success rate and a good safety profile.

Predictors of failure and complications of catheter-directed interventions for pulmonary embolism

OBJECTIVE

Catheter-directed interventions (CDIs) are increasingly performed for acute pulmonary embolism (PE) as they are presumed to provide similar therapeutic benefits to systemic thrombolysis while decreasing the dose of thrombolytic required and the associated risks. This study aimed to identify factors associated with CDI failure and to describe anticipated complications.

METHODS

Consecutive patients who underwent CDI for massive or submassive PE between 2009 and 2015 were identified; outcomes and complications were retrospectively collected. CDI clinical failure was defined as major bleeding, perioperative stroke or other major adverse procedure-related event, decompensation for submassive or persistent shock for massive PE, need for surgical thromboembolectomy, or in-hospital death. Univariate analysis was used to study the factors associated with CDI failure.

RESULTS

There were 102 patients who received a CDI during the study period (36 standard catheter thrombolysis, 60 ultrasound assisted, 6 other; age, 59.2 ± 15.9 years; male, 50 [49.0%]; massive PE, 14 [13.7%]). Five patients (4.9%) had a major contraindication and 15 patients (14.7%) had a minor contraindication to systemic thrombolysis. The mean alteplase dose was 28.2 ± 18.8 mg (range, 0-123 mg; three patients had already received systemic lysis). CDI failure occurred in 15 patients (14.7%; 7 in massive PE, 8 in submassive PE). Of these patients, seven had major bleeding events, whereas eight patients decompensated. Ten (9.8%) patients had minor bleeding events (four access related). Factors associated with CDI failure and major bleeding included massive PE, age ≥70 years, and major contraindication to thrombolytics. Both failures and bleeding events were independent of lysis dose and CDI technique.

CONCLUSIONS

CDIs for acute PE are not risk-free procedures, and their use should be individualized on the basis of a risk-benefit ratio. Particularly for patients with major contraindications to systemic thrombolytics, CDIs should be used selectively. Lytic dose, within the low-volume range administered in CDI, and type of CDI seem to have no impact on adverse events.

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

OBJECTIVE

Catheter-directed interventions (CDIs) are increasingly performed for acute pulmonary embolism (PE) as they are presumed to provide similar therapeutic benefits to systemic thrombolysis (ST) while decreasing the associated complications. The purpose of this study was to compare outcomes between CDI and ST.

METHODS

Consecutive patients who underwent CDIs or ST for massive or submassive PE between 2006 and 2016 were identified. Clinical and echocardiographic parameters at baseline and after treatment were recorded. Clinical success was defined as decompensation resolution (or prevention) without major bleeding, stroke, other major treatment-related event, or in-hospital death. The χ² test and t-test were used for between-groups comparisons.

RESULTS

There were 213 patients who received CDIs (standard catheter thrombolysis in 56, ultrasound-assisted thrombolysis in 146, suction thrombectomies in 10, and pharmacomechanical thrombolysis in 1) and 104 patients who received ST (94 high dose [100 mg], 10 low dose [50 mg]). At baseline, CDI and ST groups had comparable echocardiographic parameters, demographics, and comorbidities, except for PE type (massive PE, 8.5% for CDIs vs 69.2% for ST; P < .001), age (60.2 ± 14.9 years for CDIs vs 55.9 ± 17.3 years for ST; P = .023), and renal function (glomerular filtration rate, 78.1 ± 33.7 mL/min/1.73 m² for CDIs vs 64.1 ± 35.2 mL/min/1.73 m² for ST; P = .001). Without stratifying per PE type, CDIs had a higher clinical success rate (87.8% vs 66.3%; P < .001) and a lower rate of major bleed (8.0% vs 19.2%; P = .003), stroke (1.4% vs 4.8%; P = .120), and death (1.4% vs 13.5%; P < .001). On stratifying by PE type, there was no difference in clinical success between groups. The mean reduction in right ventricular/left ventricular diameter ratio between baseline and the first post-treatment echocardiographic examination (within 30 days) was significantly higher for CDI (0.27 ± 0.20 vs 0.18 ± 0.15; P = .037). Beyond 30 days, there was no echocardiographic difference between groups. There was no significant difference in clinical outcomes and echocardiographic parameters between standard and ultrasound-assisted CDIs.

CONCLUSIONS

CDIs provide improved recovery of right ventricular function compared with ST. Major bleeding and stroke complications may be lower, but larger studies are needed to validate this. CDIs are complementary to ST, and their use should be individualized on the basis of the patients' clinical presentation, risk profile, and local resources.