The association between the prognostic nutritional index and 28-day mortality among atrial fibrillation patients in China over 80 years of age

The most prevalent form of cardiac rhythm abnormality among older populations is atrial fibrillation (AF). The prognostic nutritional index (PNI) is a reliable predictor of mortality in various diseases. The association between the PNI and mortality among AF patients over 80 years remains uncleared.A retrospective assessment of AF cases admitted to a single cardiovascular disease unit in China between January 2015 and June 2020 was performed. The PNI at admission was defined as 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (per mm3). The association between PNI and cardiovascular disease (CVD)-related or all-cause mortality within 28 days was assessed via multivariable Cox regression. The analysis included 1141 patients. The CVD-related and all-cause mortality rates were 3.3% and 8.7%. Kaplan-Meier analyses revealed that cases with lower PNI tertiles exhibited higher all-cause mortality (T1: 7.6%; T2: 6.1%; T3: 2.4%, P < 0.001) or CVD mortality (T1: 6.3%; T2: 2.9%; T3: 0.8%, P < 0.001). After adjusting for potential confounders, continuous PNI was negatively related to the hazard of all-cause mortality (HR 0.92, 95% CI 0.89, 0.96) and CVD-related mortality (HR 0.90, 95% CI 0.84, 0.95). Compared to the T1 group, patients with a higher PNI exhibited a lower risk of all-cause mortality (P for trend 0.003) and CVD-related mortality (P for trend 0.005). Among most subgroups, CVD-related and all-cause mortality decreased with elevating PNI values.PNI is significantly negatively correlated with CVD-related and all-cause mortality among AF cases over 80 years.