Method for monitoring the evolution of heart failure in a patient comprising determining in vitro a physiological human parameter in a patient comprising the steps consisting of: i) measuring values of two or more human parameters (P P ..P) at time t1 wherein one or more of the human parameters (P P ..P) is obtained from a human physiological fluid sample ii) measuring values of the same two or more parameters (P P ..P) at time t2 different from time t1 and iii) determining the physiological human parameter wherein the physiological human parameter is a plasma volume variation ?V between time t2 and time t1 from the values (P P ..P P P ..P) obtained at times t1 and t2 and devices for implementing said method.
