The role of cholesterol in the development of cardiovascular disease was elucidated in the second half of the 20th century. This lipid hypothesis prompted attempts to reduce cardiovascular disease burden by lowering cholesterol. Treatment consisted mainly of dietary measures, such as a low-fat diet, and poorly tolerated medicines, such as clofibrate, cholestyramine, and nicotinic acid. Cholesterol researcher Daniel Steinberg writes that while the Coronary Primary Prevention Trial of 1984 demonstrated cholesterol lowering could significantly reduce the risk of heart attacks and angina, physicians, including cardiologists, remained largely unconvinced. Scientists in academic settings and the pharmaceutical industry began trying to develop a drug to reduce cholesterol more effectively. There were several potential targets, with 30 steps in the synthesis of cholesterol from acetyl-coenzyme A.