# Heart failure subtype after acute kidney injury

## TL;DR

This study explores how different types of heart failure are linked to acute kidney injury and finds that mild kidney injury is more associated with a specific type of heart failure.

## Contribution

The study identifies a potential subtype-specific relationship between acute kidney injury and heart failure, suggesting distinct mechanisms based on AKI severity.

## Key findings

- Stage 1 AKI was associated with higher odds of HFpEF (adjusted OR 0.62).
- Stages 2–3 AKI showed a trend toward HFrEF but did not reach statistical significance.
- AKI overall trended toward a preferential association with HFpEF in adjusted analyses.

## Abstract

Acute kidney injury (AKI) is associated with increased risk of heart failure (HF). Determining the type of HF experienced by AKI survivors (heart failure with preserved or reduced ejection fraction, HFpEF or HFrEF) could suggest potential mechanisms underlying the association and opportunities for improving post-AKI care.

In this retrospective study of adults within the Vanderbilt University health system with a diagnosis of HF, we tested whether AKI events in the two years preceding incident HF associated more with HFpEF or HFrEF while controlling for known predictors. HF outcomes were defined by administrative codes and classified as HFpEF or HFrEF by echocardiogram data. We used multivariable logistic regression models to estimate the effects of AKI on the odds of incident HFpEF versus HFrEF.

AKI (all stages) trended towards a preferential association with HFpEF in adjusted analyses (adjusted OR 0.80, 95% CI 0.63 – 1.01). Stage 1 AKI was associated with higher odds of HFpEF that was statistically significant (adjusted OR 0.62, 95% CI 0.43 – 0.88), whereas stages 2–3 AKI showed a trend toward HFrEF that did not reach statistical significance (adjusted OR 1.11, 95% CI 0.76 – 1.63).

AKI as a binary outcome trended towards a preferential association with HFpEF. Stage 1 AKI was associated with higher odds of HFpEF, whereas stage 2–3 trended towards an association with HFrEF that did not meet statistical significance. Different mechanisms may predominate in incident HF following mild versus more severe AKI. Close follow-up with particular attention to volume status and cardiac function after discharge is warranted after even mild AKI.