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

In the ATTRACT trial, 691 patients were randomized to receive, or not receive, pharmacomechanical catheter-directed thrombolysis (PCDT) to treat acute proximal deep vein thrombosis (DVT). Serious adverse events and suspected PE (collectively, "late symptom events", LSEs) were reported. An independent physician, blinded to treatment allocation, categorized LSEs occurring 1-24 months post-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, but PCDT did not influence their occurrence (PCDT 11.0% vs. No-PCDT 11.0%, p=1.000). However, in the iliofemoral DVT subgroup, PCDT Arm patients had fewer PE-related LSEs per patient (PCDT 0.14 vs. No-PCDT 0.24, p=0.036) and fewer PE-related breathing/lung LSEs per patient (PCDT 0.08 vs. No-PCDT 0.16, p=0.023). These findings suggest that assessment for post-PE syndrome after DVT thrombolysis can be focused on studies of iliofemoral DVT patients with PE symptoms at baseline.