Utility of Inferior Vena Cava Filters in Severe Pulmonary Embolism, Catheter-directed Therapy in Massive and Submassive Pulmonary Embolism, and HAS-BLED Score to Determine Risk of Major Hemorrhage in Pulmonary Embolism
Authors: Anish K. Desai, Joyce Pang, Malaygiri Aparnath, Jonathan Ilowite
Journal: American Journal of Respiratory and Critical Care Medicine (2016)

The American College of Chest Physicians and the American Society of Hematology advocate use of an inferior vena cava (IVC) filter only when anticoagulation is contraindicated, whereas the Society of Interventional Radiology has a list of absolute, relative, and prophylactic indications (2–4). To clarify this issue further, Mismetti and colleagues performed a prospective, randomized, open-label study evaluating the efficacy and safety of retrievable IVC filters for preventing pulmonary embolism (PE) recurrence in patients presenting with acute severe PE and superficial venous thrombosis or deep venous thrombosis (DVT) (1). A total of 399 patients from 17 French centers were openly randomized to either a retrievable IVC filter plus anticoagulation group (n = 200) or an anticoagulation-only group (n = 199). Approximately 65% of patients in each group had evidence of right ventricular dysfunction. Primary outcome was recurrence of fatal or symptomatic nonfatal PE at 3 months. Secondary outcomes were fatal or nonfatal symptomatic PE at 6 months and new or recurrent symptomatic DVT at 3 and 6 months. By 3 months, PE had recurred in six patients in the filter group and three patients in the control group (relative risk with filter, 2.00; 95% confidence interval [CI], 0.51–7.89; P = 0.50). One additional PE recurrence was observed in each group between 3 and 6 months. No difference was observed between the two treatment groups with respect to DVT, major bleeding, or death from any cause at 3 and 6 months. This is a landmark clinical trial as it sheds light on outcomes after IVC filter placement in patients with non–high-risk PE and superficial venous thrombosis or DVT who are also anticoagulated. An earlier study performed by the same investigators determined that in patients with proximal DVT on anticoagulation, IVC filters reduced the risk of PE but increased that of DVT and did not affect survival (5). The strengths of this study are in its originality, the clinical relevance of the subject matter, and the multicenter and prospective nature. A major limitation is that the patient characteristics selected to determine PE severity are not the ones in current use. Standardized criteria for PE severity, such as the Pulmonary Embolism Severity Index score or the classification of patients with acute PE on the basis of early mortality risk proposed by the European Society of Cardiology, were not available while this study was being undertaken (6, 7). Thus, this study may not represent the population that best benefits from an IVC filter placement. An exceptionally high filter retrieval rate seen in this study (79%) will be very difficult to duplicate in the community, leading to increased complications such as DVT, filter migration, and IVC stenosis (8). Another minor limitation was the time (7 yr) needed to complete this study. Studies with inclusion criteria that are better validated to measure PE severity are needed to define the specific role of IVC filters. n