The purpose of this study was to evaluate the long-term safety and tolerability of ezetimibe 10 mg once daily co-administered with atorvastatin 10 to 80 mg daily for up to 12 consecutive months in participants with heterozygous familial hypercholesterolemia (HeFH) or in participants with coronary heart disease (CHD) or multiple cardiovascular risk factors and primary hypercholesterolemia not controlled by a starting dose (10 mg daily) of atorvastatin.

Adult participants with a diagnosis of HeFH or CHD or multiple risk factors (≥2) and with primary hypercholesterolemia who had successfully completed the 14-week, double-blind efficacy and safety study of ezetimibe co-administered with atorvastatin (Protocol No. P00693/MK-0653-030; NCT03867318) were eligible for enrollment in this long-term extension study.

Inclusion Criteria:

• Participants who have successfully completed the 14-week double-blind, efficacy and safety study of SCH 58235 in addition to atorvastatin in participants with CHD or multiple risk factors or HeFH, (Protocol P00693/MK-0653-030; NCT03867318). Entry into this protocol must occur at the time of completion of Protocol P00693/MK-0653-030; NCT03867318
• All women must have a negative pregnancy test prior to study entry. Women of child bearing potential must agree to practice an effective barrier method of birth control for the duration of the study. In addition, participants must agree to practice an effective barrier method of birth control for 30 days following the last dose of atorvastatin administered
• Postmenopausal women who are receiving postmenopausal hormonal therapy or raloxifene must be maintained on a stable estrogen (ERT), estrogen/progestin (HRT) or raloxifene regimen during study period

Exclusion Criteria:

• Participants who discontinued from the Protocol P00693 due to adverse events or poor compliance
• Pregnant or lactating women
• Participants who are known to be HIV positive