SUMMARY: The Center for Disease Control and Prevention (CDC) estimates that approximately 1-2 per 1000 individuals develop Deep Vein Thrombosis/Pulmonary Embolism (PE) each year in the United States, resulting in 60,000 – 100,000 deaths. Even though Deep Vein Thrombosis (DVT) commonly occurs in the lower extremities, Non-Leg Deep Venous Thromboses (NLDVT) at other sites including the head and neck, trunk, and upper extremities can occur as well. Approximately one third of the patients with proximal Deep Vein Thrombosis (DVT) develop Post Thrombotic Syndrome which can be associated with pain and swelling in the extremity and if persistent, over time, can lead to skin pigmentation and ulceration, impacting the patients quality of life. Several small clinical studies have shown a decrease in the incidence of Post Thrombotic Syndrome, with Catheter Directed Thrombolysis (CDT), although safety outcomes from this intervention remained inconclusive. This had resulted in conflicting recommendations from the American Heart Association and American College of Chest Physicians. To address this further, the authors in this study compared safety outcomes in a group of patients with proximal and caval DVT who underwent CDT plus anticoagulation with another group treated with anticoagulation alone. In this propensity-matched analysis, 90,618 patients with a discharge diagnosis of proximal DVT over a 6 year period and 3,594 well-matched patients in each study group were identified from a Nationwide Inpatient Sample (NIS) database. The primary endpoint of this study was in-hospital mortality and secondary endpoints included incidence of pulmonary embolism, blood transfusion requirements, gastrointestinal bleeding, intracranial bleeding, IVC filter placement, procedure-related hematomas, length of hospital stay and hospital charges. This analysis did not demonstrate a significant difference in the in-hospital mortality between patients who had Catheter Directed Thrombolysis (CDT) plus anticoagulation group and the anticoagulation alone group (1.2% vs 0.9%). However, the rates of blood transfusion (11.1% vs 6.5%), pulmonary embolism (17.9% vs 11.4%), intracranial hemorrhage (0.9% vs 0.3%) and IVC filter placement (34.8% vs15.6%), were significantly higher in the CDT group compared to the anticoagulation alone group. Further, patients in the CDT group had a significantly longer hospital stay (7.2 vs. 5.0 days) and incurred significantly higher hospital expenses ($85,094 vs $28,164). More patients with private insurance had Catheter Directed Thrombolysis (CDT), compared to self-pay patients or those with Medicare or Medicaid (7.3% vs 2.8%, P<0.001). The authors concluded that Catheter Directed Thrombolysis (CDT) may not improve outcomes for patients with proximal Deep Vein Thrombosis but is associated with significantly higher adverse events and therefore warrants substantial justification, if this intervention is planned. Bashir R, Zack CJ, Zhao H, et al. JAMA Intern Med. 2014;174:1494-1501