Acute type A aortic dissection (AAAD) is a life-threatening cardiovascular emergency that requires rapid diagnosis and surgical intervention. Despite advances in surgical techniques, the in-hospital mortality rate for AAAD patients remains alarmingly high, ranging from 18% to 25%. In search of predictive biomarkers to improve early risk stratification, a study published in The Journal of Clinical Hypertension (2025) explored the prognostic significance of the neutrophil percentage to albumin ratio (NPAR) in predicting in-hospital mortality among AAAD patients.
This retrospective cohort study analyzed 813 AAAD patients who underwent surgical treatment at the Cardiac Medical Center of Fujian Province between January 2020 and April 2024. The study excluded patients with conditions or treatments that could confound blood biomarker levels, such as autoimmune diseases or recent glucocorticoid use. Patients were categorized into three groups based on tertiles of NPAR: low (<21.87), middle (21.87–24.81), and high (>24.81).
Key Findings:
Out of 813 patients, 137 (16.9%) died during hospitalization. The in-hospital mortality rates were dramatically stratified by NPAR levels: 2.2% in the lowest tertile, 15.3% in the middle, and 33.0% in the highest tertile. Multivariate logistic regression confirmed that high NPAR is an independent risk factor for in-hospital mortality, with odds ratios of 3.041 and 6.586 for the middle and highest tertiles, respectively.
Moreover, higher NPAR levels were associated with increased incidences of acute kidney injury (AKI) and multiple organ dysfunction syndrome (MODS), as well as longer intensive care unit (ICU) stays. These relationships persisted even after adjusting for variables like cardiopulmonary bypass (CPB) time and mechanical ventilation duration—both also independently associated with mortality.
The Biology Behind NPAR:
NPAR combines two readily available laboratory values: the percentage of neutrophils—a marker of systemic inflammation—and serum albumin, which reflects both nutritional status and anti-inflammatory capability. Elevated neutrophil levels correlate with the release of inflammatory cytokines, matrix metalloproteinases (MMPs), and reactive oxygen species (ROS), all of which contribute to aortic wall degeneration and rupture risk. Meanwhile, hypoalbuminemia may signal poor nutritional status, oxidative stress, and diminished anticoagulant function, all exacerbating patient outcomes.
By merging these two indicators, NPAR acts as a more comprehensive marker of systemic inflammatory and nutritional states than either metric alone. This dual sensitivity likely accounts for its stronger predictive power, as demonstrated by its superior area under the receiver operating characteristic (ROC) curve (AUC = 0.708) compared to neutrophil percentage (AUC = 0.649) and albumin alone (AUC = 0.622).
Statistical and Clinical Significance:
NPAR’s optimal cutoff value was 24.105, yielding a sensitivity of 73.7% and a specificity of 64.8% in predicting in-hospital mortality. The authors emphasize the practicality of implementing NPAR in clinical workflows due to its simplicity, cost-efficiency, and reliance on routine lab data.
Subgroup Analysis:
Interestingly, the predictive power of NPAR was consistent across various subgroups—regardless of age, sex, body mass index (BMI), systolic and diastolic blood pressure, hemoglobin levels, or comorbid conditions. This robustness enhances its appeal as a universal biomarker for AAAD prognosis.
Limitations:
As a single-center, retrospective study, the findings are subject to selection bias. Furthermore, the study used only initial lab values without capturing dynamic changes in NPAR throughout hospitalization. The authors also note the absence of other inflammatory biomarkers, such as C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR), which could provide additional context.
Conclusion:
This landmark study provides compelling evidence that NPAR is an independent and robust predictor of in-hospital mortality in AAAD patients. With its superior predictive accuracy, clinical accessibility, and cost-effectiveness, NPAR could be integrated into existing risk stratification models to identify high-risk patients early. Such integration would facilitate timely interventions, reduce complications like AKI and MODS, and ultimately improve survival rates.
The findings invite future prospective, multi-center trials to validate the role of NPAR and to explore its utility in conjunction with other biomarkers such as CRP or NLR (neutrophil-to-lymphocyte ratio). For now, clinicians managing AAAD may benefit from considering preoperative NPAR in their decision-making protocols.
