The purpose of this study is to see whether subjects with gout who receive febuxostat or allopurinol for up to 9 years have a higher rate of serious heart and blood vessel complications (major cardiovascular events). Examples of major cardiovascular events include heart attacks, strokes, and angina (chest pain due to narrowing of the blood vessels of the heart) that need to be treated urgently with a heart operation. The overall duration of the study is dependent on the number of predefined major cardiovascular events (MACE). The length of study is expected to be approximately 9 years in order to observe the required 624 MACE. The length of study participation for each subject will vary due to the event driven study design.