A five-year, single-centre experience on ultrasound-assisted, catheter-directed thrombolysis in patients with pulmonary embolism at high risk and intermediate to high risk

Aims: In this single-centre study, we aimed to evaluate the short- and long-term efficacy and safety outcomes of ultrasound-assisted thrombolysis (USAT) performed in patients with acute pulmonary embolism (PE) at intermediate to high risk and high risk (IHR, HR).

Methods and results: The study group comprised 141 retrospectively evaluated patients with PE who underwent USAT. Tissue-type plasminogen activator (t-PA) dosage was 36.1±15.3 mg, and infusion duration was 24.5±8.1 hours. USAT was associated with improvements in echocardiographic measures of right ventricle systolic function, pulmonary arterial (PA) obstruction score, right to left ventricle diameter ratio (RV/LV), right to left atrial diameter ratio and PA pressures, irrespective of the risk (p<0.0001 for all). In-hospital mortality, major and minor bleeding rates were 5.7%, 7.8% and 11.3%, respectively. Follow-up data (median 752 days) were available in all patients. Absolute and % changes in RV/LV and % changes in PA mean pressure were significantly higher in patients younger than 65 years compared with older patients, whereas bleeding, 30-day and long-term mortality were not related to age, t-PA dosage or infusion duration. HR versus IHR increased 30-day mortality.

Conclusions: USAT was associated with improvements in thrombolysis and stabilisation of haemodynamics along with relatively low rates of complications in patients with PE, regardless of the risk status. However, HR still confers a higher short-term mortality. Increasing the t-PA dosage and prolongation of infusion may not offer benefit in USAT treatments.