BACKGROUND AND AIMS: Guidelines recommend high-intensity statins for patients with atherosclerotic cardiovascular disease (ASCVD). Subgroups with comorbidities that increase cardiovascular risk, such as diabetes mellitus (DM), chronic kidney disease (CKD) or polyvascular disease (PoVD), may derive greater absolute benefit from addition of non-statin therapies. We assessed the relationship between lower low-density lipoprotein cholesterol (LDL-C) and major adverse cardiovascular events (MACE) risk reduction during alirocumab phase III ODYSSEY trials among these subgroups. METHODS: Patient data were pooled from nine trials comparing alirocumab with control (placebo/ezetimibe), predominantly on background maximally tolerated statin. Patients with baseline ASCVD were stratified into subgroups with DM, CKD or PoVD, or without comorbidities, and between-group relative and absolute benefits were compared. RESULTS: Among 3505 patients with ASCVD, 1573 had no comorbidities, 981 had DM, 660 had CKD and 943 had PoVD, with overlap between comorbidities; mean baseline LDL-C levels were 119 (ASCVD overall), 123, 117, 114 and 113 mg/dL, respectively. Overall, each 39 mg/dL lower on-study LDL-C was associated with a 25% lower MACE risk, hazard ratio 0.75 (95% confidence interval, 0.62-0.90, p = 0.0023), with a similar lower risk observed in each very high-risk subgroup (DM, CKD or PoVD; 30-35%) but not in the subgroup without these comorbidities (9%). Absolute benefits were greater for very high-risk subgroups; lowering LDL-C from 120 to 40 mg/dL would result in 2.76-4.35 fewer MACE/100 patient-years versus 0.3 for no comorbidities. CONCLUSIONS: Among patients with ASCVD and mean baseline LDL-C >100 mg/dL, patients with DM, CKD or PoVD appeared to derive greater absolute cardiovascular benefits from further LDL-C reduction than those without.