Eliminate LDL cholesterol after heart attack … but only for a while

Abstract

There is a clear demonstration of the inverse linear correlation between LDL cholesterol levels and clinical benefit. However, the timing of the action of lipid-lowering drugs is not clear. According to animal studies with recombinant lipoprotein A-1, the composition of atherosclerosis changes within 40 h (with variations in lipid and inflammatory contents). Progression–regression studies of atherosclerosis in humans confirm the data, highlighting a rapid change in the plaque over 5 weeks. The data are also in line with what emerges from the survival curves of the old study comparing atorvastatin 80 mg vs. placebo (Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering). The spacing of the curves occurs after only 4 weeks, indicating the precociousness of the favourable effects of powerful statins. Finally, a recent Odyssey post hoc analysis compared the risk of cardiac death and coronary revascularization between a group in which alirocumab lowered LDL cholesterol to below 15 mg (Group 1 and in which the drug was therefore stopped) against the subjects in the placebo group (Group 2), applying a propensity score matching. The primary endpoint occurred in a lower percentage of patients in Group 1 (6.4 vs. 8.4%). Furthermore, patients in Group 1 had a significantly lower hazard ratio (HR) for major adverse cardiovascular events [0.72; 95% confidence interval (CI) 0.51–0.997; P = 0.047] compared with the entire alirocumab group vs. placebo (HR 0.85; 95% CI 0.78–0.93; P < 0.001). According to these preliminary observations, aggressive and early treatment of hypercholesterolaemia in subjects with acute coronary syndrome translates into improved clinical results compared with a strategy that provides for more gradual control. These data will need to be confirmed through further prospective clinical studies and ideally with early conducted atherosclerosis regression studies.