Comparison of the low-density lipoprotein cholesterol target value and the preventive effect of statins in elderly patients and younger patients

OBJECTIVE: To assess whether the low-density lipoprotein cholesterol (LDL-C) target value and preventive effect of statins are different between elderly and younger patients. METHODS: We investigated 304 patients with previous percutaneous coronary intervention who underwent coronary angiography from January 2007 to December 2016 for examination of recurrent ischemia beyond the early restenosis. Patients were classified into two groups: age ≥ 75 years (elderly group: n = 140) and < 75 years (younger group: n = 164). Relationships between the achieved LDL-C level, incidence of late coronary events, and the effectiveness of statins were evaluated. RESULTS: During follow-up, 179 patients underwent late coronary revascularization. Recurrent ischemia presenting as acute coronary syndrome (ACS) occurred in 83 cases. Kaplan-Meier curve analysis revealed that in the younger group, recurrent ACS was significantly lower in patients with LDL-C < 70 mg/dL than in those with LDL-C ranging from 70 to < 100 mg/dL (P = 0.035); however, there was no difference between these in the elderly group (P = 0.863). Instead, recurrent ACS was less frequent in patients with LDL-C ranging from 70 mg/dL to < 100 mg/dL than in those with LDL-C ≥ 100 mg/dL in the elderly group (P = 0.033). Statin use was associated with decreased recurrent ACS (P = 0.005); moreover, only using statins was an independent predictor in the elderly group (HR: 0.375; P = 0.007). CONCLUSIONS: Strict control of LDL-C to < 70 mg/dL was effective for reducing the incidence of recurrent ACS in younger patients. However, LDL-C < 100 mg/dL might be sufficient as the target value of LDL-C-lowering therapy for secondary prevention of ischemic events in Japanese elderly patients.