Clinical Efficacy and Safety of Evolocumab in High-Risk Patients Receiving a Statin: Secondary Analysis of Patients With Low LDL Cholesterol Levels and in Those Already Receiving a Maximal-Potency Statin in a Randomized Clinical Trial.

Importance: Current guidelines for atherosclerotic cardiovascular disease focus on high-intensity statins and targeting or using a threshold low-density lipoprotein cholesterol (LDL-C) level of less than 70 mg/dL for the highest-risk patients. Whether further reduction of LDL-C beyond these boundaries would be beneficial is unknown.

Objective: To compare outcomes of evolocumab vs placebo in patients with stable atherosclerotic cardiovascular disease and a baseline LDL-C of less than 70 mg/dL and in those receiving background treatment with a maximal-potency statin.

Design, Setting, and Participants: This secondary ad hoc analysis of the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk (FOURIER) trial compared randomized treatments in 2 subgroups of patients with stable atherosclerotic cardiovascular disease currently receiving statin. Patients were classified by a baseline LDL-C of less than 70 or at least 70 mg/dL and by statin intensity (maximal: atorvastatin calcium, 80 mg/d, or rosuvastatin, 40 mg/d; submaximal: all other dosages). Patients with baseline LDL of less than 70 mg/dL either had a final screening LDL-C of at least 70 mg/dL or a final screening non-high-density lipoprotein cholesterol level of at least 100 mg/dL. Data were retrieved from 2013 to 2016 and analyzed in 2017 based on intention to treat.

Main Outcomes and Measures: The primary efficacy endpoint was the composite of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization. The secondary efficacy endpoint was the composite of cardiovascular death, myocardial infarction, or stroke. Safety outcomes included adverse events and events of interest identified in the FOURIER trial. Interaction testing was used to assess the consistency of results in patients who did vs did not satisfy the above criteria.

Results: A total of 27 564 patients (75.4% men and 24.6% women; mean [SD] age, 62.5 [9.0] years) were included in the analysis. Of 2034 patients (7.4%) who had a baseline LDL-C of less than 70 mg/dL, evolocumab reduced the risk for the primary endpoint (hazard ratio [HR], 0.80; 95% CI, 0.60-1.07) to a similar degree as in the 25 529 patients who had baseline LDL-C of at least 70 mg/dL (HR 0.86; 95% CI, 0.79-0.92; P = .65 for interaction; 1 patient was missing baseline LDL-C data). Of 7533 patients (27.3%) receiving maximal-potency statins, evolocumab significantly reduced the primary endpoint (HR, 0.86; 95% CI, 0.75-0.98) to a similar degree as in the 20 031 patients not receiving a maximal-potency statin (HR, 0.85; 95% CI, 0.78-0.93; P = .88 for interaction). The key secondary endpoint was reduced to a similar degree in both analyses. No major safety concerns were identified.

Conclusions and Relevance: Evolocumab was equally effective in reducing cardiovascular events in patients with stable atherosclerotic cardiovascular disease regardless of whether the baseline LDL-C was less than 70 or at least 70 mg/dL and whether the background statin was of maximal or submaximal potency.