EvidenceAlerts

Ho KM, Rao S, Honeybul S, et al. A Multicenter Trial of Vena Cava Filters in Severely Injured Patients. N Engl J Med. 2019 Jul 25;381(4):328-337. doi: 10.1056/NEJMoa1806515. Epub 2019 Jul 7. (Original study)
Abstract

BACKGROUND: Whether early placement of an inferior vena cava filter reduces the risk of pulmonary embolism or death in severely injured patients who have a contraindication to prophylactic anticoagulation is not known.

METHODS: In this multicenter, randomized, controlled trial, we assigned 240 severely injured patients (Injury Severity Score >15 [scores range from 0 to 75, with higher scores indicating more severe injury]) who had a contraindication to anticoagulant agents to have a vena cava filter placed within the first 72 hours after admission for the injury or to have no filter placed. The primary end point was a composite of symptomatic pulmonary embolism or death from any cause at 90 days after enrollment; a secondary end point was symptomatic pulmonary embolism between day 8 and day 90 in the subgroup of patients who survived at least 7 days and did not receive prophylactic anticoagulation within 7 days after injury. All patients underwent ultrasonography of the legs at 2 weeks; patients also underwent mandatory computed tomographic pulmonary angiography when prespecified criteria were met.

RESULTS: The median age of the patients was 39 years, and the median Injury Severity Score was 27. Early placement of a vena cava filter did not result in a significantly lower incidence of symptomatic pulmonary embolism or death than no placement of a filter (13.9% in the vena cava filter group and 14.4% in the control group; hazard ratio, 0.99; 95% confidence interval [CI], 0.51 to 1.94; P = 0.98). Among the 46 patients in the vena cava filter group and the 34 patients in the control group who did not receive prophylactic anticoagulation within 7 days after injury, pulmonary embolism developed in none of those in the vena cava filter group and in 5 (14.7%) in the control group, including 1 patient who died (relative risk of pulmonary embolism, 0; 95% CI, 0.00 to 0.55). An entrapped thrombus was found in the filter in 6 patients.

CONCLUSIONS: Early prophylactic placement of a vena cava filter after major trauma did not result in a lower incidence of symptomatic pulmonary embolism or death at 90 days than no placement of a filter. (Funded by the Medical Research Foundation of Royal Perth Hospital and others; Australian New Zealand Clinical Trials Registry number, ACTRN12614000963628.).


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Ratings
Discipline Area Score
Hemostasis and Thrombosis 7 / 7
Surgery - Neurosurgery 7 / 7
Internal Medicine 6 / 7
Intensivist/Critical Care 6 / 7
Surgery - Orthopaedics 6 / 7
Emergency Medicine 4 / 7
Comments from MORE raters

Emergency Medicine rater

Emergency physicians are typically only involved in the care of severely injured patients for the first few hours. The decision to insert a filter likely would not be made by the emergency physician regardless of treatment effectiveness.

Emergency Medicine rater

Small study of peripheral interest to EM.

Emergency Medicine rater

Interesting and important trial evidence implying that early (within 72 hours) vena cava filters do not reduce either symptomatic PE or death. However, those who survive >7 days and did not receive prophylactic anticoagulation show a strong signal of benefit (0% vs 15% symptomatic PE by day 90). The decision to place vena cava filter will always rest with the surgical team, so the topic is of peripheral relevance to emergency medicine.

Emergency Medicine rater

Professional recommendations on the utility of prophylactic IVC filter placement in trauma patients are conflicting, largely due to a lack of adequate evidence. This is the largest RCT of prophylactic IVC filter placement in trauma patients with immediate contraindications to prophylactic anticoagulation. There was no overall reduction in the incidence of PE or death by 90 days (RR 0.99, CI 0.51-1.94). In the small subgroup of patients who still had not received prophylactic anticoagulation by 7 days, there was a small reduction in PE between 7 and 90 days, but no change in death. One third of patients did not have the filter removed, mostly due to loss of follow-up. This trial supports a recommendation to withhold prophylactic IVC filter placement, at least during the initial 7 days of injury, although smaller benefits cannot be excluded (study was powered at 80% to detect a 8.5% absolute reduction in events). The high failure to retrieve rates also support a more measured approach.

Hemostasis and Thrombosis rater

Informative study that further debunks the perceived value of IVC filters.

Hemostasis and Thrombosis rater

Yet another nail in the coffin for IVC filters. A well done RCT that shows no benefit to ICV filters in the trauma setting.

Intensivist/Critical Care rater

I think the practice of prophylactically placing IVC filters for "high risk" patients is regional. But in places where it is common practice, this article is very informative and practice-changing. This study shows that prophylactic IVC filters do not work for this purpose.

Intensivist/Critical Care rater

Very well done article with good discussion of the limitations of the study. This article will have significant impact on surgical trauma teams that most often make the decision about inserting IVC filters. It will have less of an impact on most medical intensivists unless they are asked to weigh-in on the benefits of prophylaxis IVC filters in this subgroup of patients. A future study will need to address insertion of filters based on serial ultrasound studies in patients who are unable to be anticoagulated.

Surgery - Neurosurgery rater

While the primary end point was not reached, this study puts to rest the question regarding the usefulness of prophylactic vena cava filters in polytraumas.

Surgery - Orthopaedics rater

This study did not result in a lower incidence of symptomatic pulmonary embolism or death at 90 days than did no placement of a filter.
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