Patients were randomly assigned to receive either 10 mg or 80 mg of atorvastatin daily for an average of 4.9 years. The researchers monitored them for several heart disease outcomes: heart attack, stroke, cardiac arrest, and death from heart disease. The researchers were not aware of the dose of atorvastatin during the study, nor were the patients, their doctors, or the doctors who decided whether the patients had had a heart disease outcome.