Introduction In 2021, the Heart Failure Association of the European Society of Cardiology, the Heart Failure Society of America, and the Japanese Heart Failure Society published the Universal Definition and Classification of Heart Failure Consensus Statement,1 introducing a new category of heart failure, called heart failure with improved ejection fraction (HFimpEF) in addition to the three well-known categories of heart failure—heart failure with reduced ejection fraction (HFrEF), heart...