Circulation is a scientific journal published by Lippincott Williams & Wilkins for the American Heart Association. The journal publishes articles related to research in and the practice of cardiovascular diseases, including observational studies, clinical trials, epidemiology, health services and outcomes studies, and advances in applied (translational) and basic research. From 1996 to 2004, its impact factor remained close to 10. As of 2012, its impact factor was 15.202 and it ranked first among journals in the Cardiac and Cardiovascular Systems, Peripheral Vascular Disease categories.