Dose-Response Relationship between C-Reactive Protein/Albumin Ratio and In-Hospital Mortality in Elderly Patients with Acute Ischemic Stroke

Abstract

<b><i>Introduction:</i></b> The C-reactive protein/albumin ratio is a reliable indicator of outcome risk in several diseases. This study aims to evaluate prognostic power of the C-reactive protein/albumin ratio for in-hospital mortality and the dose-response relationship between the two in the oldest-old patients with acute ischemic stroke. <b><i>Methods:</i></b> A longitudinal observational study was conducted on patients with acute ischemic stroke (aged ≥80 years) from two tertiary hospitals between January 1, 2014, and January 31, 2020. Based on the tertiles of the C-reactive protein/albumin ratio, the patients were divided into three groups. Restrictive cubic spline and robust locally weighted regression analysis were performed on continuous variables to examine the dose-response relationship between the C-reactive protein/albumin ratio and in-hospital mortality risk. All-cause mortality during hospitalization was the outcome for this study. <b><i>Results:</i></b> The study included 584 patients (mean age = 84.6 ± 3.1 years; 59.6% men). The C-reactive protein/albumin ratio was divided into three groups, namely, T1 of &lt;0.73, T2 of 0.73–2.03, and T3: &gt;2.03. After adjusting for demographic and clinical characteristics, a higher C-reactive protein/albumin ratio was independently associated with in-hospital mortality. The hazard ratio for this association was 2.01 (95% confidence interval: 1.12–3.60, <i>p</i> = 0.019). A dose-response relationship between the C-reactive protein/albumin ratio and in-hospital mortality risk was observed. Sensitivity analysis found no attenuation in the hazard ratio in uninfected individuals, whereas no difference in the hazard ratio was noted in individuals with infections. <b><i>Conclusions:</i></b> When predicting in-hospital mortality in the oldest-old patients with ischemic stroke, the C-reactive protein/albumin ratio might be a helpful and convenient metric.