Heart failure in chronic kidney disease: what the second universal definition changes

Heart failure and chronic kidney disease (CKD) are biologically entwined and clinically difficult to disentangle. The 2026 Second Universal Definition of Heart Failure reframes heart failure as a syndrome defined by symptoms and signs, objective evidence of structural or functional cardiac abnormality, and a dynamic disease trajectory. Its implications for CKD and dialysis require focused consideration.

This review interprets the consensus in a nephrology context. It considers the move beyond rigid left ventricular ejection fraction (LVEF) thresholds; the recognition of at-risk and pre-heart-failure stages; causal classification; trajectories of improvement, remission, recovery, worsening, and decompensation; and the effects of social and geographic context.

In CKD, dyspnoea, oedema, biomarker elevation, and cardiac structural abnormalities are frequent but individually non-diagnostic. Diagnosis requires integration of longitudinal symptoms, congestion, imaging, biomarkers, volume status, and response to treatment. The new framework is especially pertinent to dialysis, where fluid shifts, access flow, myocardial stunning, and altered biomarker clearance complicate phenotyping. It also supports earlier prevention, careful distinction between worsening and decompensated heart failure, and aetiology-directed evaluation rather than reliance on LVEF or administrative hospitalisation codes.

The consensus offers nephrology a coherent vocabulary. Its value will depend on avoiding diagnostic inflation, standardising heart-failure phenotyping in CKD trials, and integrating cardiac and kidney care before recurrent congestion and kidney failure occur. It should also improve shared decision making by separating potentially reversible congestion from chronic cardiac disease, and by defining realistic therapeutic aims: prevention, symptom relief, fewer decompensations, preservation of function, and longer survival.