Evaluating prognostic factors for submassive pulmonary embolism to guide invasive therapy decisions at the Centre Hospitalier Universitaire de Sherbrooke
Charles St-Arnaud, Bobby Gouin, Mandy Malick, Justin SaurelIntroduction:
The role of invasive strategies such as catheter-directed thrombectomy in high-risk submassive pulmonary embolism remains uncertain, as pivotal trials have relied on surrogate end points. This study evaluated outcomes among patients with high-risk submassive pulmonary embolism treated with anticoagulation alone at a single institution and compared them with published interventional cohorts.
Methods:
A retrospective cohort study was conducted of adults admitted to the Centre Hospitalier Universitaire de Sherbrooke between 2018 and 2023 with confirmed pulmonary embolism, hemodynamic stability, and CT evidence of right ventricular strain (RV/LV > 0.9). Patients who initially received thrombolysis or catheter-based intervention were excluded. The primary outcome was major adverse events within 30 days, defined as a composite of death, hemodynamic or respiratory decompensation, or major bleeding.
Results:
Eighty-eight patients were included (mean age, 68.3 ± 11.7 years; 47.7% female; 69.3% with a simplified Pulmonary Embolism Severity Index score ≥ 1). Within 30 days, 2 patients (2.3%; 95% CI, 0.3%–8.0%) experienced major adverse events, consisting of hemodynamic decompensation ( n = 2), including 1 in-hospital death. No major bleeding or recurrent pulmonary embolism occurred. Prognostic markers, including the right ventricular-to-left ventricular ratio, troponin level, and simplified Pulmonary Embolism Severity Index score, were not significantly associated with outcomes. Results were comparable to those of interventional trials despite the study cohort being older and at higher risk.
Discussion:
Anticoagulation alone resulted in few adverse events and outcomes comparable to those reported in invasive thromboaspiration trials. Routine mechanical intervention may not be required for most patients with high-risk submassive pulmonary embolism. Future work should refine risk stratification, particularly for patients with cardiopulmonary comorbidities, who may represent a subgroup at greater risk.