The present invention relates to the use of cardiac hormones, particularly natriuretic peptides, for diagnosing the risk of suffering from a cardiovascular complication, particularly heart disease or acute coronary syndrome, as a consequence of cardiotoxic medication, in particular chemotherapeutics, including anthracyclines. In particular, the invention relates to a method for diagnosing the risk of a patient who is going to receive cardiotoxic medication of suffering from a cardiovascular complication as a consequence of the cardiotoxic medication, comprising the steps of (a) taking a body fluid or tissue sample, and (b) measuring, preferably in vitro, the level of a cardiac hormone. Preferred cardiac hormones in the context of the present invention are ANP, NT-proANP, BNP, and NT-proBNP.