Impact of sirolimus on long‐term adverse cardiovascular outcomes in kidney transplant recipients: A nationwide cohort study

BACKGROUND: Kidney transplant recipients (KTRs) are at high risk for cardiovascular disease due to the long-term use of immunosuppressive therapy. This study aims to evaluate the long-term impact of sirolimus on cardiovascular outcomes in Korean KTRs. METHODS: From a cohort of 7180 eligible KTRs identified from 2010 to 2021, 387 KTRs who received sirolimus were included. To control for confounding variables, propensity score matching was applied, and the landmark method was used to address immortal time bias. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of myocardial infarction, coronary revascularization, ischaemic stroke and all-cause mortality. RESULTS: The analysis showed no significant difference in MACE between the sirolimus-treated and untreated groups (hazard ratio, 1.40; 95% confidence interval, .77-2.55), despite a higher incidence of dyslipidaemia in the sirolimus-treated group. However, subgroup analysis revealed an increased MACE risk in KTRs with pre-transplant congestive heart failure (CHF) who were treated with sirolimus (hazard ratio, 6.22; 95% confidence interval, 1.78-21.74), while no significant differences were found in other subgroups. CONCLUSIONS: These findings suggest that while sirolimus can be a viable option for immunosuppression, it should be used cautiously in those with pre-existing CHF.