Negative Association of GNRI with All-Cause Mortality in Chinese Atrial Fibrillation Patients: A Multicenter Retrospective Cohort Study

Introduction: Malnutrition is common in older atrial fibrillation (AF) patients and results in poor clinical outcomes. The Geriatric Nutritional Risk Index (GNRI) is a straightforward method for evaluating nutritional health. However, its prognostic value in AF patients is unclear. This research focused on examining the correlation between GNRI and overall mortality in Chinese individuals with AF. Methods: We performed a multicenter retrospective study at four Chinese hospitals involving patients diagnosed with AF between January 2019 and August 2023. Using GNRI, nutritional status was evaluated, classifying patients into three categories. Multivariable logistic regression and restricted cubic spline analysis assess the relationship between GNRI and mortality, with exploratory subgroup analyses investigating potential effect modifiers. Results: The study included 4,878 AF patients with a median follow-up of 19 months. The mean age was 71 (63–78), and the mean GNRI was 102 (95–108). Malnutrition was identified in 1,776 patients (36.41%). During the study, 419 (8.59%) deaths occurred. After controlling for confounders, moderate to severe malnutrition was linked to an increased risk of all-cause mortality compared to no malnutrition (odds ratio 1.50; 95% CI, 1.17–1.94). The relationship between GNRI and mortality risk was approximately linear, with consistent associations across subgroups. Conclusion: Malnutrition, as assessed by GNRI, is prevalent among Chinese AF patients and is independently linked to higher all-cause mortality risk.