Intermediate-risk pulmonary embolism (PE) has anticoagulation as the standard treatment, while reperfusion strategies remain a matter of debate. In this context, mechanical thrombectomy has emerged as a potential alternative by avoiding the use of fibrinolytics, although evidence remains limited in terms of hard clinical outcomes. Therefore, a systematic review and meta-analysis was conducted to compare mechanical thrombectomy versus anticoagulation in patients with intermediate-risk PE.
The primary endpoint was all-cause mortality (in-hospital and at 30 days), while secondary endpoints included length of hospital stay and duration of stay in the intensive care unit (ICU). A total of 7 studies (1 randomized and 6 observational) were included, comprising 2,699 patients: 1,362 (50.5%) treated with mechanical thrombectomy and 1,337 (49.5%) with anticoagulation.
The population included both general intermediate-risk PE patients and subgroups with intermediate-high risk or submassive PE, reflecting a cohort with right ventricular dysfunction and/or myocardial injury. In clinical practice, the indication for thrombectomy was mostly linked to patients with a higher thrombotic burden or risk of hemodynamic deterioration, often in settings where thrombolysis was not desirable (due to bleeding risk or clinical decision), rather than a homogeneous, protocol-driven selection. Devices used included large-bore aspiration and thrombectomy systems (FlowTriever, Indigo, Lightning), while the control group received low molecular weight heparin or unfractionated heparin.
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Regarding the results, mechanical thrombectomy was associated with a significant reduction in 30-day mortality (OR 0.09; 95% CI 0.02–0.41; p=0.002), representing a very marked relative reduction (approximately 91%), although based on infrequent events, resulting in a small absolute difference. No significant differences were observed in in-hospital mortality (OR 0.62; 95% CI 0.19–2.03; p=0.29). There were also no differences in length of hospital stay (mean difference −1.85 days; 95% CI −4.60 to 0.89; p=0.13) or ICU stay (mean difference −0.48 days; 95% CI −2.62 to 1.67; p=0.53), with high heterogeneity observed in these latter outcomes.
Conclusion: Mechanical thrombectomy in intermediate-risk PE: reduced 30-day mortality without impact on other outcomes
In summary, in patients with intermediate-risk PE, mechanical thrombectomy is associated with lower 30-day mortality compared with anticoagulation, without a significant impact on in-hospital mortality or on the duration of hospital or ICU stay. However, these findings are mainly driven by observational studies, with potential selection bias and a low number of events, and should therefore be interpreted with caution. The results highlight the need for larger randomized clinical trials to better define the role of mechanical thrombectomy in this population.
Original Title: Mechanical Thrombectomy Versus Anticoagulation in Intermediate-Risk Pulmonary Embolism: A Systematic Review and Meta-Analysis.
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