NEJM March 2026: Volume 394, Issue 11 – Latest Research

The balance of benefits and risks in anticoagulant medication is a constant area of refinement in clinical practice. New research published this week in the New England Journal of Medicine, specifically in the March 12, 2026 issue (Volume 394, Issue 11), sheds further light on the comparative safety profiles of two commonly prescribed oral anticoagulants – apixaban and rivaroxaban – when used to treat acute venous thromboembolism (VTE). VTE encompasses conditions like deep vein thrombosis (DVT) and pulmonary embolism (PE), where blood clots form in the veins.

Comparing Bleeding Risks in Real-World Settings

The study, detailed on pages 1051-1060 of the journal, analyzed data from a large cohort of patients diagnosed with acute VTE. Researchers sought to determine whether there were significant differences in the incidence of major bleeding events between those treated with apixaban and those treated with rivaroxaban. Both apixaban and rivaroxaban belong to a class of drugs called direct oral anticoagulants (DOACs), which have become increasingly popular alternatives to warfarin due to their convenience – they require less frequent monitoring and have fewer dietary restrictions.

Venous thromboembolism, or VTE, affects hundreds of thousands of people each year. According to the Centers for Disease Control and Prevention (CDC), approximately 900,000 Americans are affected by DVT, PE, or both each year. CDC VTE Statistics. The primary goal of treatment is to prevent the clot from growing and to reduce the risk of future clots, but this must be carefully balanced against the risk of bleeding, a known side effect of all anticoagulant medications.

Study Design and Key Findings

This particular research employed a retrospective cohort design, meaning researchers looked back at existing data from electronic health records. This approach allows for the study of large populations but is subject to certain limitations, as discussed below. The study included a substantial number of patients, enhancing the statistical power of the findings. The primary endpoint was the occurrence of a major bleeding event, defined according to standardized criteria.

The results indicated a statistically significant difference in bleeding risk between the two drugs. Patients treated with rivaroxaban experienced a higher rate of major bleeding events compared to those treated with apixaban. While the absolute difference in risk was relatively small, the finding is clinically relevant given the large number of patients who receive these medications. It’s important to note that the study did not investigate the reasons *why* this difference exists, only that a difference was observed.

Understanding Absolute vs. Relative Risk

It’s crucial to interpret these findings in the context of absolute versus relative risk. The study likely reported a relative risk ratio, which expresses the difference in risk as a proportion. However, the absolute risk difference – the actual difference in the percentage of patients experiencing a bleeding event – is often more meaningful for both clinicians and patients. For example, a relative risk increase of 20% might sound alarming, but if the baseline risk of bleeding is very low, the absolute increase in risk may be quite small. Without access to the specific numbers from the study, it’s difficult to quantify this difference, but it’s a critical consideration when evaluating the clinical significance of the findings.

Limitations and Considerations

As a retrospective study, this research is susceptible to confounding factors. Confounding occurs when other variables, not accounted for in the analysis, influence the relationship between the anticoagulant drug and bleeding risk. For example, patients prescribed rivaroxaban might have had different underlying health conditions or risk factors for bleeding compared to those prescribed apixaban. Researchers attempted to adjust for these factors statistically, but residual confounding is always a possibility.

the study relied on data from electronic health records, which may be incomplete or inaccurate. The definition of a “major bleeding event” can similarly vary across different healthcare settings, potentially introducing bias. The study population may not be fully representative of all patients with VTE, limiting the generalizability of the findings.

What In other words for Patients and Clinicians

These findings do not necessarily mean that rivaroxaban is an inferior drug to apixaban. Both medications remain effective treatments for VTE, and the choice of which drug to use should be individualized based on a patient’s specific clinical characteristics, risk factors, and preferences. However, the study provides additional evidence to support the consideration of apixaban as a first-line option, particularly in patients at higher risk of bleeding.

It’s important for patients to discuss the risks and benefits of all anticoagulant medications with their healthcare provider. Patients should also be aware of the signs and symptoms of bleeding, such as unusual bruising, nosebleeds, or blood in the urine or stool, and seek medical attention promptly if they occur. The National Blood Clot Alliance (https://www.stoptheclot.org/) provides valuable information for patients and families affected by blood clots.

The Evolving Landscape of Anticoagulation Guidance

Current guidelines from organizations like the American College of Chest Physicians (ACCP) recommend DOACs, including apixaban and rivaroxaban, as preferred agents for the treatment of VTE. These guidelines are regularly updated as new evidence emerges. The results of this study are likely to be considered in future revisions of these guidelines, potentially leading to more nuanced recommendations regarding the selection of anticoagulants.

Ongoing research is focused on identifying biomarkers that can predict an individual’s risk of bleeding while on anticoagulation therapy. This could allow for more personalized treatment strategies, minimizing the risk of adverse events. Further studies are also needed to investigate the optimal duration of anticoagulation therapy for different types of VTE and in different patient populations.

What comes next: The findings from this study will likely prompt further investigation into the mechanisms underlying the observed difference in bleeding risk between apixaban and rivaroxaban. Researchers may conduct additional studies, including randomized controlled trials, to confirm these findings and to explore potential strategies for mitigating bleeding risk in patients treated with either drug. Clinicians should remain vigilant in monitoring patients for bleeding events and adjusting treatment as needed.