Impact of reperfusion therapies on clot resolution and long-term outcomes in patients with pulmonary embolism: a retrospective observational study

Abstract

Background: Major progress in reperfusion strategies has substantially improved the short-term outcomes of patients with pulmonary embolism (PE), however, up to 50% of patients report persistent dyspnea after acute PE. This study aims to evaluate the impact of reperfusion therapies on clot resolution and compare the long-term outcomes following acute PE in patients treated with reperfusion therapies to anticoagulation alone. Methods: A retrospective study of the pulmonary embolism response team (PERT) registry at our institution between January 2017 and June 2021 and included patients with repeat imaging at 3 to 12 months. The primary outcome was to determine the incidence of residual pulmonary vascular obstruction (RPVO) following acute PE and clot burden was assessed for each patient. Secondary outcomes included the development of PE recurrence, right ventricular (RV) dysfunction, chronic thromboembolic pulmonary hypertension (CTEPH), readmission, and mortality at 12 months. Results: A total of 382 patients were included and 107 patients received reperfusion therapies followed by anticoagulation. Patients who received reperfusion therapies including systemic thrombolysis, catheter-directed thrombolysis and mechanical thrombectomy presented with a higher vascular obstructive index (VOI, 47% vs 28%, p<0.001), more frequent concomitant deep vein thrombosis (DVT, 69% vs 40%, p<0.001), and right heart strain on both computed tomographic pulmonary arteriography (CTPA, 82% vs 37%, p<0.001) and echocardiogram (81% vs 43%, p<0.001) at the time of diagnosis. A higher absolute reduction in VOI (45% vs 26%, p<0.001, 95% CI 14.0-25.6), greater improvement in RV function (82% vs 65%, p=0.021), lower 12-month mortality rate (2% vs 7%, p=0.038) and readmission rate (33% vs 46%, p=0.031) were observed in the reperfusion group. No statistically significant differences were found between groups in the development of CTEPH (8% vs 5%, p=0.488) and PE recurrence (8% vs 6%, p=0.646). Conclusion: We observed a more favorable survival, greater improvement in clot resolution and RV function in patients treated with reperfusion therapies. Future randomized control trials are needed to confirm our findings.