Assessing real-world effectiveness of atorvastatin in patients with type 2 diabetes mellitus for the primary prevention of cardiovascular events

Background and aims: In contrast to the substantial body of clinical trial evidence, the real-world evidence regarding the efficacy of statins in the prevention of cardiovascular events among patients with type 2 diabetes mellitus (T2DM) is relatively limited. Therefore, we assessed the effectiveness of atorvastatin for the primary prevention of CV events in patients with T2DM, using a population-based data in South Korea. Methods and results: This retrospective cohort study was conducted using the National Health Insurance Service Customized Database (2008–2018) in South Korea. We identified atorvastatin users and statin non-users with T2DM without history of cancer or CV events. The two groups were matched using propensity scores. The association between CV events and atorvastatin was estimated using an extended Cox model with the Heaviside function (split at 3 years). We identified 41 024 atorvastatin users and 41 024 statin non-users (mean age: 58.1 and 58.2 years, respectively). The incidence rate and case fatality rate of CV events were higher in statin non-users than in atorvastatin users. Atorvastatin significantly reduced the risk of CV events after 3 years of treatment (hazard ratio [HR]: 0.98 (95 % confidence interval: 0.90–1.05) and 0.76 (0.72–0.80) within and after 3 years, respectively). The HR for stroke was lower than that for coronary heart disease. Conclusion: In real-world patients with T2DM without a history of CV events, atorvastatin was associated with a decreased risk of CV events after 3 years of treatment.