Association of red blood cell distribution width to albumin ratio with the prognosis of acute severe pulmonary embolism: A cohort study

Red blood cell distribution width (RDW) to human serum albumin (ALB) ratio (RDW/ALB Ratio, RAR) is a prognostic factor for adverse outcomes in different disease populations. However, the relationship between RAR and pulmonary embolism outcomes remains unclear. Therefore, this study set out to investigate the association between RAR and the risk of all-cause death in acute pulmonary embolism (APE) patients admitted to the intensive care unit (ICU). This is a retrospective study based on the MIMIC-IV database. The primary outcome was all-cause mortality among patients with APE (in-hospital and 1-year mortality). The relationship between RAR and all-cause mortality was assessed using Cox regression analysis. The survival curve was drawn to evaluate the predictive value of RAR for patient mortality. Correlations and threshold effects between RAR and all-cause mortality were analyzed using the generalized additive model (GAM). The study included 773 patients, and fully adjusted Cox regression models showed that RAR was associated with higher all-cause mortality in the hospital and one year later (all P < .05). In the GAM, the relationship between RAR and all-cause mortality was shown to be nonlinear, with a positive association between RAR and all-cause mortality in APE patients when RAR values were at low to moderate levels. This study revealed a significant association between RAR and the risk of all-cause day death in patients with pulmonary embolism. Higher RAR value was associated with increased in-hospital mortality and 1-year mortality.