Ultrasound‐assisted catheter‐directed thrombolysis compared with anticoagulation alone for treatment of intermediate‐risk pulmonary embolism

Abstract

It is unclear if ultrasound-assisted catheter-directed thrombolysis (UACDT) confers benefit over anticoagulation (AC) alone in the management of intermediate-risk (“submassive”) pulmonary embolism (PE), defined by evidence of right ventricular (RV) dysfunction in hemodynamically stable patients. This study sought to evaluate any lasting advantage of UACDT on mortality and resolution of RV dysfunction in intermediate-risk PE at a large academic medical center. Adults aged ≤ 86 years admitted with intermediate-risk PE from 2011 to 2016 were retrospectively identified. Patients were excluded if there was a history of cancer, pre-existing pulmonary hypertension, pregnancy or postpartum status, contraindication to AC, or treatment with systemic thrombolysis. Baseline Pulmonary Embolism Severity Index (PESI) scores were computed. Outcomes including length of stay (LOS), bleeding complications, resolution of RV dysfunction, and mortality were compared between patients who received UACDT and those managed with AC alone. A total of 104 patients met inclusion criteria, 65 of whom underwent UACDT. The cohorts had similar PESI scores (P = 0.45) and no clearly imbalanced confounding variables. There was no significant difference in LOS (P = 0.11). UACDT was associated with more bleeding complications (exact P = 0.04). Follow-up transthoracic echocardiograms performed in 54 UACDT and 24 AC patients demonstrated similar rates of resolution of RV dysfunction (61% in UACDT patients versus 75% in AC patients, P = 0.25). Overall one-year mortality was approximately 5% in both groups (exact P > 0.99). In this limited retrospective analysis of intermediate-risk PE patients, UACDT treatment was not associated with mortality benefit or increased resolution of RV dysfunction.

Ultrasound-Responsive Cavitation Nuclei for Therapy and Drug Delivery

“…However, a large-sample randomly assigned prospective clinical trial is needed to improve the clinical evidence for use as a front-line therapy for DVT. In retrospective studies in patients with pulmonary embolism, Lee et al (2017) conclude that catheter-directed sonothrombolysis is tolerable and decreases right-sided heart strain, but Schissler et al (2018) conclude that this therapy is not associated with a reduction in mortality or increased resolution of right ventricular dysfunction. And finally, an ongoing trial in a small cohort of 20 patients with acute peripheral arterial occlusions (Ebben et al 2017) will determine whether Luminity (marketed in the United States as Definity) and 1.8 MHz transdermal diagnostic ultrasound with intermittent high MI (1.08) and low MI (0.11) for visualization of the microbubbles and flow will improve recanalization.…”

Lifting the fog in intermediate-risk (submassive) PE: full dose, low dose, or no thrombolysis?

“…revealed no significant difference in outcomes or complication rates between the two techniques 39 . More recently, similar results were reported by Schissler et al ., who found no significant differences in length of hospital admission, RV dysfunction on follow-up echocardiography and 1-year mortality in patients who received this treatment modality compared with standard anticoagulation alone 40 . The SEATTLE II trial is thus far the largest study looking at the efficacy and safety of ultrasound-assisted catheter-directed fibrinolysis.…”

Management of Acute Pulmonary Embolism

“…Additionally, data available to evaluate long-term benefits of CDL therapies has been challenging to interpret. While several single-center retrospective trials have evaluated USAT versus either anticoagulation alone or non-us CDL with longer term endpoints (e.g., 12 months), such study design subjects these trials to significant bias and limit the generalizability of the results to relevant clinical populations [ 25 , 26 •, 32 ]. Thus, while limited high-quality data exist on the use of CDL in acute PE, it appears to have a lower rate of overall bleeding and ICH in comparison with ST in acute PE with encouraging outcomes at 30 days.…”