Background
Sodium abnormality is common in patients with heart failure (HF) and is associated with adverse clinical outcomes. The aim of this study is to determine the impact of abnormal sodium burden on long‐term mortality and hospitalization in HF with preserved ejection fraction (HFpEF).
Methods
We analysed participants from the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial with available baseline and follow‐up data (n = 1717). Abnormal sodium burden was defined as the proportion of days with abnormal sodium plasma levels (either <135 mmol/L or > 145 mmol/L). To determine the independent prognostic impact of abnormal sodium burden on the long‐term clinical adverse outcomes (The primary outcome was any cause death, the secondary outcomes include cardiovascular disease death, HF hospitalization, any cause hospitalization and the primary endpoint of the original study), a multivariable Cox proportional hazard model and time‐updated Cox regression model were performed.
Results
Abnormal sodium burden occurred in 717 patients (41.76%). A high abnormal sodium burden was associated with 1.47 (95% CI, 1.15–1.89) higher risk with any cause mortality, 1.51 (95% CI, 1.08–2.09) higher risk with CVD death and 1.31 (95% CI, 1.02–1.69) higher risk with HF hospitalization when compared with no burden group. When sodium level changes over time were accounted for in time‐updated models, abnormal sodium level was still associated with poor clinical outcomes. Diuretic and spironolactone usage did not show a statistical interaction effect on the prognostic significance.
Conclusions
In HFpEF patients, abnormal sodium burden was an independent predictor long‐term any‐cause mortality and HF hospitalization.