Enoxaparin Fails to Reduce VTE risk among Hospitalized Older Adults: NEJM

In a recent trial, low-molecular-weight heparin (enoxaparin) failed to demonstrate a reduction in the risk of symptomatic VTE within one month through the use of enoxaparin in medically ill, hospitalized older adults. The findings were published in NEJM Evidence.

The trial, which enrolled patients over the age of 70, aimed to determine whether enoxaparin could effectively reduce the incidence of VTE in this high-risk population. Conducted at 47 centers, the trial was prematurely discontinued in September 2020 due to drug supply issues, after five years of enrollment. By that time, 2,559 patients had been randomly assigned to receive either enoxaparin or a placebo for a period of 6 to 14 days. The median age of the participants was 82 years, with 60% being female.

The primary efficacy outcome measured was the cumulative incidence of symptomatic VTE, including distal or proximal deep vein thrombosis and fatal or nonfatal pulmonary embolism, at 30 days. The primary safety outcome assessed was major bleeding. Secondary outcomes, including efficacy and safety measures, were evaluated at the 90-day mark.

Among the intention-to-treat population, the trial results indicated that the primary efficacy outcome occurred in 1.8% of patients in the enoxaparin group (22 out of 1,278) and 2.2% of patients in the placebo group (27 out of 1,263). The difference in cumulative incidence between the two groups was not statistically significant, with a cumulative incidence difference of -0.4 percentage points and a confidence interval of -1.5 to 0.7. The time to VTE also did not differ significantly between the groups.

Regarding safety outcomes, the incidence of major bleeding was similar between the enoxaparin group (0.9%) and the placebo group (1.0%). At the 90-day follow-up, there were 14 cases of symptomatic pulmonary embolism in the enoxaparin group and 25 cases in the placebo group. Unfortunately, all 39 cases of pulmonary embolism resulted in hospital readmission and/or death, with five deaths attributed to pulmonary embolism in the enoxaparin group and 11 deaths in the placebo group.

Source:

Mottier, D., Girard, P., Couturaud, F., Lacut, K., Le Moigne, E., Paleiron, N., Guellec, D., Sanchez, O., Cogulet, V., Laporte, S., Marhic, G., Mismetti, P., Darbellay Farhoumand, P., Cuvelier, C., … Le Gal, G. (2023). Enoxaparin versus Placebo to Prevent Symptomatic Venous Thromboembolism in Hospitalized Older Adult Medical Patients. In NEJM Evidence. Massachusetts Medical Society. https://doi.org/10.1056/evidoa2200332