Statin therapy and the incidence of atherosclerotic cardiovascular events after kidney transplantation

Background. Statins are recommended in kidney transplant recipients (KTRs)-a population with a high risk of major cardiovascular (CV) events. However, the literature data on the effectiveness of statins in KTRs are sparse and inconclusive. The present study's objective was to evaluate the association between statin exposure and atherosclerotic CV events in KTRs and the biochemical effectiveness of statins on the lipid profile. Methods. A total of 318 consecutive KTRs managed at a single center between 2006 and 2019 were retrospectively included. Those exposed to statins after transplantation were incident users. In all users, statins were indicated for primary CV prevention. Lipid profiles, the occurrence of any atherosclerotic CV events (stroke, myocardial infarction, other atherosclerotic CV events and atherosclerotic CV deaths) were documented comprehensively. We applied Cox models that included statin exposure as a time-dependent covariate fitted with time-varying inverse probability treatment weighting (IPTW) to assess the effectiveness of statins on atherosclerotic CV events and on all CV events. We built linear mixed models to assess the biochemical effectiveness of statins. Results. During a median (interquartile range) follow-up period of 6.0 (3.9-10.0) years, 27 atherosclerotic CV events occurred in 26 patients. In the Cox models fitted with time-varying IPTW, exposure to statins was not associated with a decrease in atherosclerotic CV events; the hazard ratio was 1.16 (95% confidence interval 0.53-2.53) (P = .700). In the linear mixed models, statin exposure was associated with significant decrease over time in triglyceride and low-density lipoprotein cholesterol concentrations (P < .001). These results were consistent when stratified for the intensity of statin therapy. Conclusion. Even though the lipid profile improved, statin exposure was not associated with a decrease in CV events in this real-life, single-center, retrospective, long-term follow-up study of a KTR cohort. Larger, controlled studies are needed to confirm or refute these results.