In May, NICE issued updated treatment guidelines for type-2 diabetes. This advice gives doctors the option of using thiazolidinediones or dipeptidyl peptidase-4 inhibitors in patients whose blood-glucose control is inadequate. However, evidence suggests that rosiglitazone may increase the risk of myocardial infarction and heart failure. Pioglitazone has not been shown to have such an effect, but since few data are available to prove pioglitazone’s cardiovascular safety, NICE recommends that neither thiazolidinedione should be given to patients with heart failure.