NPPB and hydrops fetalis: First, given the nature of claims data, there might be a significant limitation for investigating questions regarding acute HF; we were unable to evaluate clinical data which are potentially reflective of SGLT2i treatment or of the severity and progression during hospitalization including but not limited to left ventricular ejection fraction, frailty, economic background, New York Heart Association (NYHA) Functional Classification, NT-proBNP, estimated glomerular filtration rate, blood pressure, results of echocardiogram and blood test at admission, and others.