A new systematic review and meta-analysis published in BMC Pulmonary Medicine finds that ultrasound-facilitated catheter directed thrombolysis (USAT) does not significantly reduce overall all-cause mortality in patients with intermediate-risk pulmonary embolism compared with anticoagulation alone. The pooled analysis, which included six studies and 1,646 patients, reported a non-significant reduction in overall mortality (risk ratio 0.60, 95% confidence interval 0.36 to 1.02; p = 0.06), and the authors conclude that routine use of USAT over anticoagulation cannot be recommended pending adequately powered trials.
The review is presented as the first meta-analysis restricted exclusively to ultrasound-facilitated catheter devices, addressing a limitation of earlier syntheses that pooled ultrasound-facilitated and conventional catheter devices together, precluding device-specific conclusions. The authors searched four databases from inception through July 2026 following PRISMA 2020 guidance and included six studies, two randomized trials and four observational comparisons, covering intermediate or intermediate-high risk pulmonary embolism. Dichotomous outcomes were pooled as risk ratios and continuous outcomes as mean differences using random-effects models, with risk of bias assessed using the RoB 2 and Newcastle Ottawa Scale tools and certainty evaluated with GRADE.
The analysis also incorporated the newly published HI-PEITHO trial and applied trial sequential analysis (TSA) along with prespecified subgroup analyses by study design and follow-up duration. Notably, no outcome, including mortality, reached its Required Information Size on TSA, meaning the existing evidence base remains insufficient to support firm conclusions about the intervention’s effect on mortality.
While the overall mortality estimate was not statistically significant, the review did identify a significant reduction in mortality at one year (RR 0.40, 95% CI 0.19 to 0.84; p = 0.02), although the certainty of this finding was rated as very low. No significant mortality difference was observed at thirty days (RR 0.76, 95% CI 0.14 to 4.14; p = 0.75). In subgroup analyses, the one-year benefit was significant in observational studies (RR 0.50, 95% CI 0.29 to 0.86; p = 0.01) but not in randomized trials (RR 1.43, 95% CI 0.36 to 5.65; p = 0.61), a divergence that underscores the influence of study design on the pooled estimates.
Leave-one-out sensitivity analysis revealed that the overall mortality estimate remained non-significant upon removal of any single study, with one exception: removing the Rosenfield 2026/HI-PEITHO trial alone restored statistical significance (RR 0.50, 95% CI 0.29 to 0.85; p = 0.01). This dependence of the pooled result on a single trial highlights the fragility of the current evidence and the importance of the intention-to-treat analysis of HI-PEITHO’s mortality outcome, which the authors note was central to their conclusion of no significant overall mortality benefit.
Safety outcomes showed a numerical trend toward more bleeding with USAT, though neither reached statistical significance. Major bleeding was more frequent with USAT (RR 1.96, 95% CI 0.62 to 6.23), as was minor bleeding (RR 2.26, 95% CI 0.80 to 6.36). The wide confidence intervals reflect the limited number of events and participants, and the authors emphasize that these trends did not reach significance.
Several secondary outcomes showed no significant difference between the two treatment arms. Recurrent pulmonary embolism and length of hospital stay were similar between groups. Improvement in right ventricular dysfunction was numerically higher with USAT (RR 1.29, 95% CI 0.48 to 3.44) but did not reach statistical significance. Pulmonary artery pressure showed no significant difference (mean difference −1.37 mmHg, 95% CI −4.97 to 2.24) when analyzed using follow-up absolute measurements from the two eligible observational studies, excluding one randomized trial that reported a non-comparable 24-hour change from baseline value.
The authors conclude that this first device-specific synthesis, incorporating trial sequential analysis, found no significant overall mortality benefit of USAT when HI-PEITHO’s mortality outcome is analyzed on an intention-to-treat basis, with a significant reduction observed only in observational comparisons and at one year. They state that routine use of USAT over anticoagulation cannot be recommended pending adequately powered trials.
Subject of Research: Device-specific meta-analysis of ultrasound-facilitated catheter directed thrombolysis versus anticoagulation for intermediate-risk pulmonary embolism
Article Title: Ultrasound facilitated catheter directed thrombolysis versus anticoagulation alone for intermediate risk pulmonary embolism: a systematic review and meta-analysis with trial sequential analysis
Article References: Shahbaz, H., Murtaza, O., Soroush, A. R., Jawed, H. M., Mian, S., Komal, S., Anamta, F., Noor, A., Umar, M., Talha, M., Munawar, B., Jawaid, K. A., Riaz, M. M., Mahboob, Z., Khan, S. S., Sidra, A., Shah, Z. U., Qudoos, U., & Giranaz, J. (2026). Ultrasound facilitated catheter directed thrombolysis versus anticoagulation alone for intermediate risk pulmonary embolism: a systematic review and meta-analysis with trial sequential analysis. BMC Pulmonary Medicine. https://doi.org/10.1186/s12890-026-04931-7
Image Credits: AI Generated
DOI: 10.1186/s12890-026-04931-7
Keywords: pulmonary embolism, thrombolysis, ultrasound-facilitated catheter, anticoagulation, meta-analysis, trial sequential analysis, HI-PEITHO, mortality, major bleeding, intermediate-risk, BMC Pulmonary Medicine, systematic review
News Source: Ophelia Keating. (October 29, 2026). Ultrasound-guided catheter thrombolysis shows no clear mortality benefit over anticoagulation. Scienmag.
