Post-Pulmonary Embolism Syndrome: Clinical Manifestations and Interventional Radiology Treatments

Learning Objectives: 1) Understand the spectrum of Post-Pulmonary Embolism (Post-PE) Syndrome, including its clinical manifestations, diagnostic evaluation (structured algorithms), and complications.

2) Recognize the differences between chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic disease (CTED).

3) Explore interventional strategies for prevention and treatment of Post-PE Syndrome, including catheter-directed thrombolysis (CDL), mechanical thrombectomy (MT), and balloon pulmonary angioplasty (BPA).

Background: Post-PE Syndrome encompasses a spectrum of conditions that develop after acute pulmonary embolism (PE). Approximately 30-50% of patients experience residual symptoms such as chronic dyspnea and exercise intolerance after PE, even without demonstrable thromboembolic disease on imaging {1}. CTEPH, the most severe manifestation, affects 3-4% of patients following PE and is characterized by unresolved thromboemboli leading to increased pulmonary vascular resistance, pulmonary hypertension, and right ventricular failure if left untreated {2, 3}. CTED affects around 25% of patients who have persistent limitations without overt pulmonary hypertension {4, 5}.

Clinical Findings/Procedure Details: Anticoagulation represents standard care for PE patients. In addition, CDL and MT are used in carefully selected patients with acute PE to rapidly reduce thrombus burden, and ongoing studies (e.g., NIH-sponsored PE-TRACT Trial) will clarify whether they reduce the risk of post-PE complications. For patients with established CTEPH who are not surgical candidates, BPA is an emerging option.

Equally critical is structured long-term follow-up to identify post-PE sequelae early. The SEARCH algorithm (Symptom screen, Exercise testing, Arterial perfusion, Resting echocardiography, Confirmatory imaging, Hemodynamics) provides a systematic approach to evaluate patients with persistent dyspnea and exercise intolerance after PE. This framework distinguishes recovery, post-PE deconditioning, alternative causes of dyspnea, symptomatic residual pulmonary vascular obstruction, CTED, and CTEPH. Incorporating SEARCH into follow-up allows for efficient triage, targeted use of invasive testing, and identification of patients who may benefit from surgical endarterectomy, BPA, or other interventions {6}.

Conclusion and/or Teaching Points: Post-PE Syndrome represents a major cause of long-term morbidity. Beyond acute management, structured follow-up enables timely recognition of post-PE sequelae, differentiates overlapping conditions, and guides interventional treatment.