The Effectiveness of Target Low-Density Lipoprotein Cholesterol Achieved with Strict Management in Secondary Prevention of Long-Term Coronary Events in Japanese Patients

Background: In the secondary prevention of long-term coronary events, a target value of low-density lipoprotein cholesterol (LDL-C) ＜ 100 mg/dL is recommended as standard management in Japanese guidelines. However, the effectiveness of strict management on lowering LDL-C remains unclear. Objectives: To clarify whether strict management of LDL-C ＜ 70 mg/dL is more effective in preventing long-term coronary event recurrence than standard management. Methods: We retrospectively investigated 344 patients with previous percutaneous coronary interventions who underwent late coronary angiography to examine recurrence of cardiac ischemia beyond the early restenosis period from January 2007 to August 2019. Patients were stratified into three groups according to achieved LDL-C value; LDL-C ＜ 70 mg/dL (n = 53), 70 to ＜ 100 mg/dL (n = 130), and ≥ 100 mg/dL (n = 161). Endpoints were acute coronary syndrome (recurrent-ACS) and late coronary revascularization. Results: After follow-up (median 6.0 years), 200 patients (58%) underwent late coronary revascularization, including 94 recurrent-ACS. The incidence of recurrent-ACS was significantly lower in the patients who achieved LDL-C ＜ 70 mg/dL than in those with LDL-C 70 to ＜ 100 mg/dL and LDL-C ≥ 100 mg/dL (p = 0.009 and p = 0.001, respectively). There was no significant difference between the patients with LDL-C 70 to ＜ 100 mg/dL and LDL-C ≥ 100 mg/dL (p = 0.140). There was also no significant difference in late revascularization between the patients with LDL-C ＜ 70 mg/dL and LDL-C 70 to ＜ 100 mg/dL. In patients with LDL-C ＜ 100 mg/dL (n = 183), LDL-C [hazard ratio (HR) 1.035, p = 0.007] and HbA1c (HR 1.338, p = 0.001) were independently associated with recurrent-ACS. Conclusions: In Japanese patients, LDL-C was a residual risk for recurrent-ACS even after recommended standard LDL-C lowering management target values had been achieved.