A method of treating a patient having heart failure due to LV systolic dysfunction with an LV ejection fraction less than 40%. The method includes the steps of administering to a patient in need thereof, a compound selected from the group consisting of GIP, GIP analogs, GIP derivatives and pharmaceutically-acceptable salts thereof, GLP-1, GLP-1 analogs, GLP-1 derivatives and pharmaceutically-acceptable salts thereof, at a therapeutically effective amount to improve LV function.