BOSTON, February 12, 2026 — Doctors facing a ticking clock with critically ill patients now have a new tool to pinpoint those at highest risk of dying from a pulmonary embolism (PE). It’s a frustratingly common scenario: a patient in the ICU, suspected of having a blood clot in the lungs, and a desperate need for a quick, accurate assessment.
New Biomarker-Based Tool Improves PE Risk Prediction
A simple scoring system using common lab tests can help identify ICU patients with a pulmonary embolism who are most likely to die within 28 days.
- Researchers developed a nomogram—a visual tool—to assess 28-day mortality risk in ICU patients with acute PE.
- The nomogram incorporates eight readily available clinical and lab values: age, neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, red blood cell distribution width, respiratory rate, oxygen saturation, vasopressor use, and cancer diagnosis.
- The tool outperformed existing risk scores, demonstrating strong accuracy with an area under the curve of 0.772.
- Rapid risk stratification can guide treatment decisions and potentially improve outcomes for patients with PE.
What factors can help doctors quickly determine if a patient with a pulmonary embolism is at high risk of death? A new study reveals that a combination of eight easily obtainable factors—age, blood tests, respiratory rate, and whether the patient requires blood pressure support—can significantly improve risk assessment.
The study, published in Clinical and Applied Thrombosis/Hemostasis, analyzed data from 1,083 patients with acute PE admitted to intensive care units using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Researchers identified eight independent predictors of mortality. These included being older than 66 years, a neutrophil-to-lymphocyte ratio (NLR) greater than 10.1, a lymphocyte-to-monocyte ratio (LMR) less than 1.5, a red blood cell distribution width (RDW) greater than 14.35, a respiratory rate exceeding 26 breaths per minute, oxygen saturation levels, the use of vasopressors (medications to raise blood pressure), and a diagnosis of malignant cancer.
The nomogram demonstrated excellent calibration and strong discriminative ability, with an area under the receiver operating characteristic curve of 0.772 (95% CI, 0.732-0.811; P < 0.001). This means it was better at correctly identifying high-risk patients than existing risk scores. The simplicity of the tool—relying on routinely collected data—makes it easily implementable in busy ICU settings.
By rapidly identifying patients with PE who are at the highest risk of death, clinicians can make more informed decisions about treatment, potentially leading to improved outcomes. The ability to quickly stratify risk is crucial for guiding interventions and optimizing care for these vulnerable patients.
Understanding the Biomarkers
The study highlights the importance of certain blood markers in predicting PE severity. For example, the neutrophil-to-lymphocyte ratio (NLR) reflects the balance between immune cells, and an elevated NLR often indicates inflammation. Similarly, the lymphocyte-to-monocyte ratio (LMR) provides insight into immune function, and a lower LMR can suggest a compromised immune response.
Red blood cell distribution width (RDW) measures the variation in red blood cell size, and a higher RDW can be a sign of underlying inflammation or stress. These biomarkers, combined with clinical factors like respiratory rate and oxygen saturation, provide a comprehensive picture of a patient’s condition.
This research underscores the need for continued investigation into biomarkers that can help refine risk assessment and improve the management of pulmonary embolism in the ICU.
