The present invention provides methods for evaluating or monitoring the efficacy of a therapeutic intervention for treating a cardiac disorder. Such methods comprise measuring or detecting the level of at least one miRNA in a biological sample from a patient receiving the therapeutic intervention and comparing the level to the level of said at least one miRNA in a control sample, wherein the measured level of said at least one miRNA is indicative of the therapeutic efficacy of the therapeutic intervention. Methods of predicting or assessing the severity or progression of heart failure in a patient by measuring one or more miRNAs in a biological sample from the patient are also disclosed.