Association between systemic inflammation and long-term mortality in emergency department patients with severe hypertension

Background The prognostic role of systemic inflammatory indicators in patients with severe hypertension remains unclear. This study evaluated the associations between several inflammatory markers, including Neutrophil-to-Lymphocyte Ratio (NLR), Lymphocyte-to-Monocyte Ratio (LMR), Platelet-to-Lymphocyte Ratio (PLR), Systemic Immune-Inflammation Index (SII), C-Reactive Protein (CRP) level, and long-term mortality.Methods This retrospective cohort included 5,320 adult patients presenting to the emergency department with severe hypertension (systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 110 mmHg) between 2016 and 2019. All patients underwent complete blood counts and CRP testing. Patients were categorized into tertiles for each inflammatory marker.Results Higher tertiles of NLR, PLR, SII, and CRP were associated with increased 3-year all-cause mortality, while higher LMR was associated with lower mortality. Adjusted hazard ratios (95% Confidence Intervals) comparing the highest to lowest tertiles were: NLR 1.61 (1.35-1.92), LMR 0.71 (0.60-0.85), PLR 1.22 (1.03-1.44), SII 1.57 (1.33-1.86), and CRP 2.21 (1.84-2.65). Dose-response analyses revealed linear associations between NLR and SII, an inverse J-shaped pattern for LMR, a J-shaped curve for PLR, and a nonlinear positive association for CRP. CRP showed the highest discriminatory performance among the evaluated markers.Conclusion Systemic inflammatory indicators were associated with long-term mortality in patients with severe hypertension. These findings suggest that inflammatory markers may provide prognostic information in this population, although their role in risk stratification and follow-up planning requires further evaluation.