The Effect of Thrombolysis of Deep Vein Thrombosis on Late Symptoms of Post-Pulmonary Embolism Syndrome.

In the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) trial, 691 patients were randomly assigned to receive or not receive pharmacomechanical catheter-directed thrombolysis (PCDT) to treat acute proximal deep vein thrombosis (DVT). Serious adverse events and suspected pulmonary embolism (PE) (collectively, "late symptom events" [LSEs]) were reported. An independent physician, blinded to treatment allocation, categorized LSEs occurring 1-24 months after randomization by whether they could relate to post-PE syndrome. PE-related LSEs were frequent (66.7%) in patients who presented with diagnosed or suspected PE and infrequent (2.0%) in others; however, PCDT did not influence their occurrence (PCDT, 11.0% vs No-PCDT, 11.0; P = 1.000). However, in the iliofemoral DVT subgroup, patients in the PCDT arm had fewer PE-related LSEs per patient (PCDT, 0.14 vs No-PCDT, 0.24; P = .036) and fewer PE-related breathing/lung LSEs per patient (PCDT, 0.08 vs No-PCDT, 0.16; P = .023). PCDT was associated with a lower incidence of PE-related LSEs in patients with iliofemoral DVT who presented with PE symptoms at baseline. Evaluation for post-PE syndrome after DVT thrombolysis can be focused on this subset of patients.