A major cause of strokes and of heart attacks is atherosclerosis, a disease of the blood vessels leading to a cholesterol coating inside arteries that can prevent the vessels from adjusting to blood flow. Cholesterol also can build up to form thicker deposits, which can produce blocked arteries and lead to stroke, in which brain cells die after being deprived of oxygen and nutrients in the blood for a few minutes or more. Speech impairment, paralysis or other complications may result. Drugs called statins lower the risk of atherosclerosis by hindering the liver's ability to make cholesterol. The liver responds by removing more cholesterol from the blood so that less of it is available to damage the inside of blood vessels.
Animal studies suggest that statins reduce stroke risk by increasing blood flow to the brain.
The drugs turn on an enzyme, nitric oxide synthase, that makes nitric oxide. This molecule dilates the arteries and increases blood flow through them. To determine if statins affect humans the same way, Derdeyn will study forty patients who have one completely blocked, carotid artery to the brain and thirty others with partially blocked, coronary arteries to the heart.