Abstract:This article introduces the key updates of the “AHA/ACC/ESC/WHF Second Edition Expert Consensus Document on the Universal Definition of Heart Failure (2026)” and proposes Chinese translation recommendations for various definitions in the new consensus. The new consensus updates the classification of heart failure based on left ventricular ejection fraction (LVEF) as follows:(1) Heart failure with reduced ejection fraction (HFrEF), LVEF<50%; (2) Heart failure with preserved ejection fraction (HFpEF), LVEF≥50%; (3) Heart failure with improved ejection fraction (HFimpEF); simultaneously, it also defines three stages in the treatment outcomes of heart failure patients:improved heart failure, remission heart failure, and recovery heart failure.