Anticoagulation alone versus large-bore mechanical thrombectomy in acute intermediate-risk pulmonary embolism.

Background: Patients with intermediate-risk pulmonary embolism (PE) have outcomes worse than uncomplicated ST elevation myocardial infarction. Yet, no large-scale study has compared the outcomes of large-bore mechanical thrombectomy (LBMT) with anticoagulation alone (AC). The aim of this study was to compare the clinical outcomes among patients receiving LBMT vs AC alone.

Methods: This was a two-center retrospective study that included patients with intermediate-risk PE from October 2016 - October 2023 from the institution's Pulmonary Embolism Response Team (PERT) database. The primary outcome was a composite of 30-day mortality, resuscitated cardiac arrest or hemodynamic decompensation. Inverse probability of treatment weighting (IPTW) was used to balance covariates; Kaplan Meir curves and IPTW multivariable Cox regression were used to assess the relationship between treatment groups and outcomes.

Results: Of the 273 patients included in the analysis, 192 (70 %) patients received AC alone and 81 (30 %) patients received LBMT and AC. A total of 30 (10.9 %) patients experienced the primary composite outcome over a median follow-up of 30 days. The primary composite outcome was significantly lower in the group that received LBMT compared to those on AC alone (1.2 % vs 15.1 %, log-rank p < 0.001; adjusted HR: 0.02; 95 % CI: 0.002-0.17, p < 0.001) driven by a lower rate of 30-day all-cause mortality (0 % vs 7.3 %, log-rank p = 0.01), resuscitated cardiac arrest (0 % vs 6.8 %, log-rank p = 0.016) and new or worsening hemodynamic instability (4 % vs 11.1 %, log-rank p = 0.007).

Conclusion: In this largest cohort to date comparing LBMT versus AC alone in acute intermediate-risk PE, LBMT had a significantly lower rate of the primary composite outcome including a lower rate of all-cause mortality when compared to AC alone. Ongoing randomized trials will test these associations.