Combination of moderate-intensity statins and ezetimibe versus high-intensity statins alone for primary prevention of cardiovascular events

Abstract Background Combination of a moderate-intensity statin with ezetimibe can lead to similar reductions in cardiovascular events as monotherapy with a high-intensity statin in patients with established atherosclerotic cardiovascular disease (ASCVD). The comparative effectiveness of these two cholesterol-lowering strategies in the primary prevention setting is unknown. Purpose To compare incident ASCVD events associated with a combination of moderate-intensity statin and ezetimibe versus monotherapy with a high-intensity statin in adults without prior history of cardiovascular disease. Methods We conducted a new-user active comparator retrospective population-based cohort study in Canada. We included all adults aged ≥ 67 years (eligible for drug coverage) with a first prescription of either a combination of moderate-intensity statin with ezetimibe ("combination therapy") or high-intensity statin alone between January 2010 and December 2022. Patients were excluded if they had not received any prior lipid lowering therapies or had a history of myocardial infarction (MI), stroke, heart failure, peripheral vascular disease or prior coronary revascularisation at any time before or within 3 months of treatment initiation. The primary outcome was a composite of all-cause death, hospitalization for MI or stroke, or coronary revascularization. An inverse probability of treatment weighting propensity score was used to account for confounding (demographics, comorbidities, laboratory tests, other medications). Results Among 67,884 patients (mean age: 74.0±5.5y; 53% females), 8,798 (13%) initiated combination therapy and 59,086 (87%) initiated a high-intensity statin. At 1 year, after weighting, the mean achieved LDL-C was ~1.9 mmol/L in both groups. The median follow-up was 6.5 years. The cumulative incidence of the primary outcome at 10 years in the weighted cohort was 32.7% in the combination therapy group and 36.1% in the high-intensity statin group (HR: 0.87; 95% CI: 0.82 to 0.92; p<0.001; absolute risk reduction: 3.5%; 95% CI: 0.8 to 6.1; Figure 1). This result was primarily driven by a lower risk of all-cause death (HR: 0.85; 95% CI: 0.80 to 0.91; p<0.001; Figure 2) and stroke (cause-specific [cs] HR: 0.86; 95% CI 0.74 to 0.99; p=0.04), whereas no differences were observed in the risk of MI (csHR: 0.97; 95% CI: 0.82 to 1.15) or coronary revascularization (csHR: 0.97; 95% CI 0.85 to 1.11). Conclusion The combination of moderate-intensity statins with ezetimibe was associated with a lower risk of incident ASCVD compared with high-intensity statins alone among primary prevention patients in a real-world setting. These results were driven by a lower risk of all-cause death and stroke, but not coronary events. The influence of statin intolerance on the allocated strategy and adherence to therapy cannot be addressed in this analysis, which, along with verifying these estimates, may be best determined in a prospective randomized trial.