Devices and methods for detecting heart failure (HF) events or identifying patient at elevated risk of developing future HF events, such as events indicative of HF decompensation status, are described. The devices and methods can detect an HF event or predict HF risk using signal transfigurations on different portions of a physiologic signal. A system can comprise a physiologic signal analyzer circuit that can generate a signal trend of a signal feature calculated using one or more physiologic signals obtained from a patient. A signal transformation circuit can dynamically generates first and second transformations, apply the transformations to respective first and second portions of the signal trend, and generate respectively a first and second transformed signal trends. A target physiologic event detector circuit can detect a target physiologic event such as an event of worsening HF using a comparison of the first and second transformed signal trends.
