 The sample size for the REVIVE II trial was estimated on the basis of the following assumptions: the proportion of patients considered improved during the first 5 days would be 50 greater in the levosimendan group than in the placebo group; the proportion of patients considered worse during the first 5 days would be 33 lower in the levosimendan group than in the placebo group; the expected rates of improvement and deterioration in the placebo group would both be 25; and the study would have 90 power to detect a treatment difference α 0.05. 