What is the fine-grained topic of the following text: A two year investigation has reviewed over 250,000 documents submitted by GlaxoSmithKline, the Food and Drugs Administration (FDA) and other organisations after the publication of a study in the New England Journal of Medicine that raised concerns that rosiglitazone increased the risk of myocardial infarction. Only return the topic.
Investigation into GlaxoSmithKline's drug rosiglitazone and its potential increased risk of myocardial infarction.