Washington University Emergency Medicine Journal Club – March 19th, 2026
Dr. Brian Cohn
Hey all,
This month’s journal club will look at the management of intermediate-risk PE, specifically evaluating PERT team activation, catheter-directed thrombolysis, and mechanical thrombectomy.
The PGY-1, PGY-2, and PGY-4 papers will be appraised using the Therapy form, while the PGY-3 paper will be appraised using the Meta-analysis form.
Vignette
You’re working one evening shift in TCC when EMS brings in a 64-year-old woman with shortness of breath and near-syncope. She reports that her symptoms began earlier that morning and have progressively worsened. She denies chest pain but feels markedly dyspneic with minimal exertion. Her past medical history is notable for hypertension and a recent knee replacement three weeks ago. Her vital signs show a heart rate of 118 bpm, blood pressure of 124/76 mmHg, respiratory rate of 24, and oxygen saturation of 92% on room air. She appears uncomfortable but is speaking in full sentences. Her exam is notable for mild tachypnea but clear lungs and no signs of heart failure.
You obtain a CT which reveals large bilateral pulmonary emboli. A bedside echocardiogram shows right ventricular dilation and hypokinesis, and her troponin returns mildly elevated. Despite these findings, she remains normotensive. Traditionally, these patients are treated with anticoagulation alone, with escalation to thrombolysis reserved for hemodynamic collapse. However, over the past several years your hospital has increasingly involved the Pulmonary Embolism Response Team (PERT) for patients like this, with consideration of mechanical thrombectomy and catheter-directed thrombolysis.
Your patient is currently stable, but her imaging and biomarkers suggest a higher-risk PE. Should she receive anticoagulation alone, the traditional standard of care? Would catheter-directed thrombolysis reduce the risk of deterioration while avoiding the bleeding risk of systemic thrombolysis? Could mechanical thrombectomy rapidly reduce clot burden without the need for thrombolytics? And does activating a PERT team actually improve outcomes, or does it simply increase the use of invasive procedures? You decide to search the literature to see what evidence exists comparing anticoagulation alone, catheter-directed thrombolysis, mechanical thrombectomy, and multidisciplinary PERT activation for patients with intermediate-risk pulmonary embolism.
PICO Question
Population: In adult patients with intermediate-risk (submassive) pulmonary
embolism
Intervention: Does management with catheter-directed thrombolysis, mechanical
thrombectomy, or activation of a pulmonary embolism response team (PERT)
Comparison: Compared with treatment with anticoagulation alone
Outcome: Improve clinically meaningful outcomes such as mortality, hemodynamic
decompensation, recurrent PE, ICU utilization, or hospital length of stay?
Article 1: Kucher N, Boekstegers P, Mü ller OJ, et al. Randomized, controlled trial of
ultrasound-assisted catheter-directed thrombolysis for acute intermediate-risk
pulmonary embolism. Circulation. 2014;129(4):479-486. [Answer Key].
Article 2: Jaber WA, Gonsalves CF, Stortecky S, et al; PEERLESS Committees and
Investigators. Large-bore mechanical thrombectomy versus catheter-directed
thrombolysis in the management of intermediate-risk pulmonary embolism:
primary results of the PEERLESS randomized controlled trial. Circulation.
2025;151(5):260-273. [Answer Key].
Article 3: Maqsood MH, Zhang RS, Rosenfeld K, Moriarty JM, Rosovsky RP, Horowitz
JM, Alviar CL, Bangalore S. Do Pulmonary Embolism Response Teams for Acute
Pulmonary Embolism Improve Outcomes? Insights from a Meta-analysis. Am J
Cardiol. 2025;249:71-82. [Answer Key].
Article 4: Lookstein RA, Konstantinides SV, Weinberg I, et al; STORM-PE Trial
Investigators. Randomized controlled trial of mechanical thrombectomy with
anticoagulation versus anticoagulation alone for acute intermediate-high-risk
pulmonary embolism: primary outcomes from the STORM-PE trial. Circulation.
2026;153(1):21-34. [Answer Key].
Bottom Line
While anticoagulation remains the mainstay of treatment for acute pulmonary embolism (PE), several relatively new therapies are available to assist in management, particularly in cases where clot burden and location lead to strain on the right heart. These alternative therapies include surgical thrombectomy, catheter-based mechanical thrombectomy, and catheter-directed thrombolysis. Many institutions have now implemented PE response teams (PERT), multidisciplinary teams designed to evaluate patients on a case-by-case basis and make recommendations regarding optimal therapy. Several recent studies have evaluated not only the individual treatment options, but also the utility of PERT in general.
The Ultrasound Assisted Thrombolysis of Pulmonary Embolism (ULTIMA) trial was a randomized, multicenter trial comparing ultrasound-assisted catheter-directed thrombolysis (USAT) to anticoagulation alone in intermediate-risk PE. USAT led to a substantially greater reduction in RV/LV ratio (mean decrease of 0.30 ± 0.20) compared with heparin alone (0.03 ± 0.16; P < 0.001), along with significant improvements in other right heart echocardiographic parameters, without differences in major bleeding, hemodynamic decompensation, or recurrent VTE at 90 days. This study unfortunately involved a very small sample size (59 patients) and focused on a short-term surrogate outcomes rather than patient-centered measures such as development of CTEPH or quality of life.
The STORM-PE trial was another international, randomized trial, this time comparing computer-assisted vacuum thrombectomy (CAVT) plus anticoagulation with anticoagulation alone in adults with intermediate-high–risk PE. The primary endpoint, change in RV/LV ratio at 48 hours, favored CAVT, with a mean reduction of 0.52±0.37 vs. 0.24±0.40 (between-group difference 0.27; 95% CI 0.12–0.43; P<0.001) and more CAVT patients achieved >0.2 reduction in RV/LV ratio. Safety outcomes were similar between groups: major adverse events within 7 days occurred in 4.3% vs 7.5%, major bleeding in 1 patient per group, and serious adverse events in 8.5% vs 15.1%. Key limitations include the small sample size (100 patients), open-label design with unblinded clinical assessments, and again the use of a short-term surrogate primary outcome (RV/LV ratio) rather than patient-centered endpoints leaving uncertainty about the true clinical benefit of CAVT.
The PEERLESS trial was an international, multicenter, randomized controlled trial comparing large-bore mechanical thrombectomy (LBMT) with catheter-directed thrombolysis (CDT) for intermediate-risk pulmonary embolism. The authors used a hierarchical win ratio composite of clinical outcomes (mortality, ICH, major bleeding, clinical deterioration/escalation, and ICU use) which strongly favored LBMT (win ratio of 5.01; 95% CI 3.68–6.97). This difference was primarily driven by a decrease in clinical deterioration/escalation (1.8% vs 5.4%) and markedly lower ICU use (41.6% vs 98.6%; ICU >24 hours 19.3% vs 64.5%). The latter was an inherently biased outcome, as most centers require ICU admission during catheter-directed thrombolytic infusion, automatically biasing the results in favor of mechanical thrombectomy. There were no differences in rates of ICH or major bleeding and mortality was very low in both groups. It should also be noted that this was an industry-funded study by the LBMT device manufacturer (Inari Medical).
Regarding the efficacy of PERT in general, a systematic review and meta-analysis identified 24 observational studies including 15,809 patients. PERT use was associated with lower in-hospital or 30-day mortality (OR 0.72, 95% CI 0.56–0.93), more frequent use of advanced therapies (OR 3.16, 95% CI 1.81–5.49), less major or clinically relevant bleeding (OR 0.60, 95% CI 0.42–0.86), and shorter hospital length of stay (mean difference −1.49 days, 95% CI −2.59 to −0.39), with no significant difference in 30-day readmission. The primary limitations of this meta-analysis were that all included studies were observational (hence at risk of selection bias, information bias, and confounding) and that most outcomes showed substantial heterogeneity between studies (I² often > 60–90%).
Overall, PERT involvement in the management of intermediate-risk PE seems to improve outcomes, current evidence does not demonstrate clear-cut patient-centered outcome benefits for the alternative therapies offered. The primary limitations of studies on these therapies include potential bias from industry funding and the use of surrogate rather than patient-centered outcomes. Anticoagulation thus remains the standard of care, with selective use of advanced interventions and multidisciplinary PERT guidance in carefully chosen patients pending larger, high-quality trials focused on meaningful clinical outcomes.