NEJM original articles

Background. Post-thrombotic syndrome is common after deep-vein thrombosis and can cause severe symptoms involving the limbs that impair patients' activity and quality of life. Endovascular therapy can eliminate chronic venous obstruction and is hypothesized to reduce the severity of post-thrombotic syndrome.

Methods. We randomly assigned 225 patients with moderate or severe post-thrombotic syndrome and imaging-confirmed iliac-vein obstruction to receive endovascular therapy (iliac-vein stent placement and enhanced antithrombotic therapy) plus standard post-thrombotic syndrome care or standard post-thrombotic syndrome care alone. The severity of post-thrombotic syndrome at 6 months (the primary outcome) was assessed with the validated Venous Clinical Severity Score (VCSS) tool (scores range from 0 to 30, with higher scores indicating more severe post-thrombotic syndrome) by evaluators who were unaware of the group assignments. Key secondary outcomes included venous disease-specific and overall quality of life.

Results. At 6 months, the severity of post-thrombotic syndrome was lower in the endovascular-therapy group than in the no-endovascular-therapy group (mean [±SD] VCSS, 8.1±5.1 vs. 10.0±4.9; adjusted difference, -2.0; P = 0.001). Venous disease-specific quality of life as assessed with the Venous Insufficiency Epidemiological and Economic Study Quality of Life questionnaire was better in the endovascular-therapy group than in the no-endovascular-therapy group at 6 months (adjusted difference, 14.5 points; P<0.001), as was overall quality of life as assessed with the Medical Outcomes Study 36-Item Short-Form Health Status Survey physical component summary score (adjusted difference, 6.1 points; P<0.001); scores on both tools range from 0 to 100. Through 6 months, bleeding was more common in the endovascular-therapy group than in the no-endovascular-therapy group (in 11.6% vs. 3.6% of the patients; P = 0.03).

Conclusions. Among patients with moderate or severe post-thrombotic syndrome and iliac-vein obstruction, endovascular therapy led to less severe post-thrombotic syndrome and better health-related quality of life than standard care over a 6-month period but with a higher risk of bleeding. (Funded by the National Heart, Lung, and Blood Institute and others; C-TRACT ClinicalTrials.gov number, NCT03250247.).

Background. Whole-blood transfusion has recently gained favor in the management of severe hemorrhage; however, data from large clinical trials evaluating its clinical effectiveness and safety are lacking.

Methods. We conducted a pragmatic, phase 3, multicenter, unblinded, randomized, superiority trial across 10 air ambulance services in England. Patients with major traumatic hemorrhage who were attended by a participating air ambulance service were randomly assigned to receive either whole-blood transfusion (up to 2 units) or standard care with blood components (up to 2 units each of red cells and plasma) before arrival at the hospital. The primary outcome was a composite of death from any cause or massive transfusion (≥10 units of blood components or products) within 24 hours after randomization.

Results. A total of 942 patients underwent randomization. After the exclusion of participants with nontraumatic hemorrhage or traumatic cardiac arrest, 616 were included in the analysis (314 in the whole-blood group and 302 in the standard-care group). A primary-outcome event occurred in 48.7% of the participants in the whole-blood group and in 47.7% of those in the standard-care group (relative risk, 1.02; 95% confidence interval, 0.80 to 1.31; P = 0.84). The incidence of death from any cause at all time points, massive transfusion, and other secondary outcomes appeared to be similar in the two groups. Prothrombin times were above the normal range in 40.7% of the participants in the whole-blood group and in 30.5% of those in the standard-care group. More serious adverse events occurred in the standard-care group than in the whole-blood group (37 and 31, respectively). The incidence of thrombotic events appeared to be similar in the two groups.

Conclusions. Among participants with life-threatening hemorrhage, prehospital transfusion of 2 units of whole blood was not superior to standard care in reducing the risk of death or massive transfusion within 24 hours. (Funded by NHS Blood and Transplant and others; ISRCTN Registry number, ISRCTN23657907.).

Background. Blood transfusion before arrival at a hospital reduces mortality from traumatic hemorrhage and shock. Whether transfusion with whole blood is more beneficial than transfusion with blood components is uncertain, as are the effects of the length of time that blood products are in storage between donation and transfusion.

Methods. In this pragmatic, multicenter, phase 3, cluster-randomized trial, we assigned 44 air medical bases in a 2:1 ratio to the use of up to 2 units of whole blood or as-indicated blood components (plasma, red cells, or both) for prehospital transfusion in trauma patients during 1-month blocks. The primary outcome was death from any cause within 30 days after randomization. An observational substudy assessed outcomes according to the storage age of whole blood.

Results. Of 1020 eligible patients transported to hospitals by the air bases, 715 were assigned to receive whole blood and 305 to receive blood components; 695 and 298, respectively, were included in the primary analysis. Mortality at 30 days was 25.9% in the whole-blood group and 20.5% in the component group (adjusted odds ratio, 1.24; 95% confidence interval [CI], 0.87 to 1.76; P = 0.24). No substantial between-group differences in adverse events were observed. In the observational substudy, 30-day mortality was 27.1% among 210 patients who received whole blood with a storage age of 15 to 21 days and 26.4% among 443 patients who received whole blood with a storage age of 1 to 14 days (adjusted odds ratio, 0.99; 95% CI, 0.74 to 1.32).

Conclusions. In injured patients with hemorrhagic shock, the use of whole blood for prehospital transfusion did not result in lower 30-day mortality than the use of blood components. (Funded by the Defense Health Agency Research Technology Portfolio Management, Combat Casualty Portfolio; TOWAR ClinicalTrials.gov number, NCT04684719.).

Background. Staphylococcus aureus bacteremia is associated with high mortality. Whether cefazolin or an antistaphylococcal penicillin should be preferred for the treatment of methicillin-susceptible S. aureus bacteremia is unclear.

Methods. In an ongoing international Bayesian adaptive platform trial, we conducted an open-label, randomized comparison of cefazolin with an antistaphylococcal penicillin (flucloxacillin or cloxacillin) in adult patients with penicillin-resistant, methicillin-susceptible S. aureus bacteremia. The primary outcome, which was evaluated with a hierarchical Bayesian logistic-regression model, was death from any cause within 90 days after enrollment in the platform. We assessed the posterior probability of the noninferiority of cefazolin to flucloxacillin or cloxacillin (with the criterion for noninferiority prespecified as an adjusted odds ratio of <1.2, which approximates an absolute difference in mortality of <2.5 percentage points if mortality in the antistaphylococcal-penicillin group is 15%), as well as the posterior probability of superiority (with the criterion of an adjusted odds ratio of <1.0). Secondary safety outcomes included the development of acute kidney injury within 14 days.

Results. This domain of the ongoing trial was conducted between February 17, 2022, and August 7, 2024, by which time the criterion for noninferiority had been met. Mortality at 90 days among adults who could be evaluated was 15.0% (97 deaths among 645 patients) in the cefazolin group and 17.0% (109 deaths among 642 patients) in the antistaphylococcal-penicillin group (adjusted odds ratio, 0.81; 95% credible interval, 0.59 to 1.12; probability of noninferiority, 99.2%; probability of superiority, 89.8%). Acute kidney injury occurred in 92 of 660 patients (13.9%) in the cefazolin group, as compared with 127 of 648 (19.6%) in the antistaphylococcal-penicillin group (adjusted odds ratio, 0.67; 95% credible interval, 0.50 to 0.89; probability of superiority, 99.7%).

Conclusions. In patients with methicillin-susceptible S. aureus bacteremia, cefazolin was noninferior to flucloxacillin or cloxacillin with respect to 90-day mortality and was associated with a lower incidence of acute kidney injury. (Funded by the National Health and Medical Research Council and others; SNAP ClinicalTrials.gov number, NCT05137119.).