Ultrasound-Facilitated, Catheter-Directed Thrombolysis for Acute Pulmonary Embolism

BACKGROUND

Acute pulmonary embolism (APE) poses a significant risk to patient health, with treatment options varying in efficacy and safety. Ultrasound-facilitated catheter-directed thrombolysis (USCDT) has emerged as a potential alternative to conventional catheter-directed thrombolysis (CDT) for patients with intermediate to high-risk APE. This study aimed to compare the efficacy and safety of USCDT versus conventional CDT in patients with intermediate to high-risk APE.

METHODS

This observational retrospective study was conducted at the Armed Forces Hospital, Al-Hada, Taif, the Kingdom of Saudi Arabia (KSA), on 135 patients diagnosed with APE and treated with either USCDT or CDT (58 underwent CDT, while 77 underwent USCDT). The primary efficacy outcome was the change in the right ventricle to the left ventricle (RV/LV) diameter ratio. Secondary outcomes included changes in pulmonary artery systolic pressure and the Miller angiographic obstruction index score. Safety outcomes focused on major bleeding events.

RESULTS

Both USCDT and CDT significantly reduced RV/LV diameter ratio (from 1.35 ± 0.14 to 1.05 ± 0.17, P < 0.001) and systolic pulmonary artery pressure (SPAP) (from 55 ± 7 mmHg to 38 ± 7 mmHg, P < 0.001) at 48- and 12-hours post-procedure, respectively, with no significant differences between treatments. However, USCDT was associated with a significantly lower rate of major bleeding events compared to CDT (0% vs. 3.4%, P = 0.008). Multivariate logistic regression analysis revealed that USCDT was associated with a 71.9% risk reduction of bleeding (OR = 0.281, 95% CI = 0.126 - 0.627, P = 0.002).

CONCLUSIONS

USCDT is a safe and effective alternative to CDT for the treatment of intermediate to high-risk APE, as it significantly reduces the risk of major bleeding.

Analysis of pulmonary embolism patients treated with EkoSonic™ endovascular system

Background

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.

Methods

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.

Results

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.

Conclusion

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.

Predictors of Treatment Response Following Ultrasound-Facilitated Catheter-Directed Thrombolysis for Submassive and Massive Pulmonary Embolism

Background:

Little is known about which factors predict improvement in clinical and imaging parameters among patients undergoing catheter-directed thrombolysis for submassive or massive pulmonary embolism. The identification of such predictors may allow for more appropriate patient selection for ultrasound-facilitated catheter-directed thrombolysis.

Methods:

We conducted a retrospective cohort analysis of patients from the SEATTLE II trial (Prospective, Single-Arm, Multi-Center Trial of EkoSonic Endovascular System and Activase for Treatment of Acute Pulmonary Embolism) to identify clinical characteristics that independently predict pulmonary artery pressures, right ventricular-to-left ventricular (RV/LV) diameter ratio, and modified Miller angiographic index following ultrasound-assisted catheter-directed thrombolysis. Eligible patients had submassive or massive pulmonary embolism and an RV/LV diameter ratio ≥0.9 on chest computed tomography. Multivariable linear regression was used to identify independent clinical predictors of each outcome.

Results:

One hundred fifty patients with massive (n=31) or submassive (n=119) pulmonary embolism were enrolled. Mean (±SD) baseline and postprocedure RV/LV diameter ratio, pulmonary artery systolic pressure, and modified Miller Score were 1.59 (±0.39) and 1.14 (±0.2), 51.45 (±16.0), and 37.47 (±11.9), and 23.0 (±5.7) and 15.7 (±5.9), respectively. The multivariable model adjusted R 2 for absolute change in RV/LV ratio, pulmonary artery systolic pressure, modified Miller Score was 0.71, 0.57, and 0.43, respectively. After adjusting for age, gender, and baseline RV/LV ratio, pulmonary artery systolic pressure, and modified Miller Score, patients with higher body mass index, renal or hepatic dysfunction, active smoking, or a higher baseline heart rate showed less improvement.

Conclusions:

Patients with more life-threatening pulmonary embolism may derive the greatest benefit from ultrasound-assisted, catheter-directed thrombolysis.