Changes in kidney function during acute heart failure hospitalization influence in-hospital mortality, but not other 90-day heart failure outcomes
A V Ofordile, B T Bello, C E Amadi, A C MbakwemAbstract
Background
Heart failure (HF) is associated with poor outcomes, particularly during hospitalization for acute exacerbations and in the early post-discharge period. Kidney function (KF) during HF hospitalization is dynamic and its trajectory may have varying prognostic implications. While some studies suggest that new-onset or worsening kidney dysfunction (KD) during HF hospitalization is detrimental and predicts poor outcomes, researchers continue to argue that worsening KF is a physiologic response to decongestive therapy and question its predictive effects on HF outcomes. Importantly, available data on the subject matter are derived from studies carried out exclusively in high-income countries whose HF populations differ both clinically and socio-demographically from those in sub-Saharan Africa.
Purpose
This study aimed to evaluate the effects of changes in KF on 90-day outcomes in a sub-Saharan African population of patients hospitalized for acute HF.
Methods
This was a prospective observational study carried out among 145 adult patients hospitalized for acute HF in a tertiary hospital in Nigeria, between May 2024 and June 2025. KF was assessed using estimated glomerular filtration rate ([eGFR] measured daily for the first seven days), and albuminuria (measured at admission). Participants were followed up for 90 days from the day of admission or until death. The study outcome measures were a composite of all-cause mortality, HF rehospitalization, unscheduled hospital visit due to worsening HF symptoms and outpatient intensification of diuretic dose (primary), and each of the components of the primary outcome measure, plus in-hospital mortality (secondary). Participants were grouped into those with stable, worsened and improved KF based on eGFR over the first seven days of admission. Hazard ratios with 95% CI, and Kaplan Meier analysis with log rank testing were used to compare 90-day outcomes between participants in the three groups, with those having stable KF serving as the reference population.
Results
Mean age was 52.2 years ± 14.9 years, with more male participants (59.3%). Most participants had new-onset HF (53.1%), and hypertensive heart disease as the underlying HF aetiology (64.1%). Median eGFR at presentation was 56.5mL (41.3-76.5) while KD was present in 141 (97.2%) of participants. Over the subsequent seven days, 50.3%, 29.7% and 20.0% of participants experienced, worsening, stable and improved KF, respectively. Participants who experienced either worsened or improved KF had 74% (HR=0.26, 95% C.I: 0.10-0.69, p=0.007) and 87% (HR= 0.13, 95% C.I: 0.03-0.56, p=0.006) decreased hazards of in-hospital mortality, respectively. Changes in KF did not significantly influence other study outcomes.
Conclusion
Changes in KF (both worsening and improved) during the first seven days of acute HF hospitalization is associated with significantly reduced hazards of in-hospital mortality.