The association between neutrophil-to-albumin ratio and mortality in patients with cardiogenic shock: a cohort study

Background Cardiogenic shock (CS) is a lethal complication. Given the poor outcome of CS, we performed a retrospective cohort study to identify whether the neutrophil-to-albumin ratio (NAR) was significantly associated with mortality from CS. Methods All patient data were extracted from the MIMIC III version 1.3. Comparisons between groups was made using the chi-square or Fisher’s exact tests for categorical variables and the variance analysis or the Kruskal-Wallis test was used for continuous variables. The primary outcome was 30-day mortality and the secondary ones were 90-day and 365-day mortality. We used Cox proportional hazards models to evaluate the association between the various categories of NAR and survival. To further identify the association, subgroup analyses were performed. Results A total of 475 patients with CS were enrolled. A significant positive correlation between NAR levels and 30-day, 90-day or 365-day mortality was observed. For the primary outcome of 30-day mortality, the HR (95% CI) values given NAR levels 23.54–27.86 and > 27.86 were 1.72 (1.17, 2.53) and 1.96 (1.34, 2.87) compared with the reference (NAR < 23.47) in tertile analysis. In multivariate analyses, the HR (95% CI) values were still of statistical significance[1.98 (1.25, 3.15) and 2.03 (1.26, 3.26)]. When quintiles were applied to grouping patients according to NAR level, similar associations were also observed. For the secondary outcomes, the upward trend remained statistically significant. Conclusions NAR level was associated with survival from CS. NAR appeared to be an independent and readily-available prognostic biomarker of mortality in patients with CS.