Work

Stroke-associated pneumonia after acute ischemic stroke: early temporal dynamics, nonlinear risk factors, and time-dependent prognostic impact

Year: 2026

Type: article

Abstract: Background Stroke-associated pneumonia (SAP) is a common complication following acute ischemic stroke, yet its early occurrence patterns, nonlinear risk factors, and time-dependent prognostic impact remain incompletely characterized. We investigated SAP incidence, temporal distribution, risk factors, and independent impact on in-hospital outcomes. Methods This single-center retrospective cohort study included 3,347 consecutive patients with acute ischemic stroke (2019–2025). SAP was diagnosed within 7 days after admission using consensus criteria. Cox models with restricted cubic splines identified risk factors and nonlinear relationships. Time-dependent Cox models, Gamma generalized linear models, and logistic regression were used to assess associations between SAP and in-hospital outcomes. Multiple imputation, complete-case, and landmark analyses verified robustness. Results SAP developed in 428 patients (12.8%), with 55.1% occurring within 72 h (peak day 3). Independent risk factors included older age (HR 1.02), pre-stroke mRS 3–5 (HR 1.39), COPD (HR 1.69), cardioembolism (HR 1.71), dysphagia (HR 2.02), and nasogastric tube insertion within 48 h (HR 2.31) (all p < 0.05). Admission NIHSS, neutrophil-lymphocyte ratio, and albumin showed nonlinear associations with SAP risk (all P-nonlinear <0.05). Time-dependent analyses revealed SAP independently associated with in-hospital death (HR 2.34), ICU transfer (HR 2.81), invasive mechanical ventilation (HR 3.47), prolonged length of stay (RoM 1.35), and poor functional outcome (OR 1.90) (all p < 0.001). Sensitivity analyses confirmed robustness. Conclusion SAP occurs early after acute ischemic stroke, with identifiable risk factors exhibiting nonlinear relationships, and independently predicts adverse in-hospital outcomes. Findings support forward-shifted preventive strategies, including early swallowing assessment, feeding pathway optimization, airway protection, and nutritional support, in high-risk patients during the first days of hospitalization.

Source: Frontiers in Neurology

DOI: 10.3389/fneur.2026.1841237