Apolipoprotein A-1 and post-transplant cardiovascular and graft outcomes after kidney transplantation: a nationwide prospective cohort (KOTRY) study

Non-traditional lipid markers such as apolipoprotein A-1 (ApoA-1) may better capture residual cardiovascular and graft risk after kidney transplantation, but data are limited. We studied 2307 kidney transplant recipients in the nationwide Korean Organ Transplantation Registry with stored serum samples. Outcomes were cardiovascular events and death-censored graft loss (DCGL). Associations were assessed using multivariable Cox, 1-year landmark, time-dependent Cox, and restricted cubic spline models. In fully adjusted models, the highest 1-year ApoA-1 tertile showed significantly reduced risk of cardiovascular events compared with the lower two tertiles (HR 0.32; 95% CI, 0.14–0.72). For DCGL, middle-to-high tertiles were associated with lower risk compared with the lowest tertile (HR 0.55; 95% CI, 0.32–0.95), but not after FDR correction (q = 0.068). Landmark analyses showed similar directions of association, although DCGL associations were attenuated after multiplicity correction. Each 10-mg/dL increase in time-updated ApoA-1 was associated with lower risks of cardiovascular events (HR 0.91; 95% CI, 0.82–1.02) and DCGL (HR 0.84; 95% CI, 0.76–0.93). Restricted cubic spline curves suggested a reduction in cardiovascular risk at higher ApoA-1 levels and an increased risk of DCGL at lower ApoA-1 levels. ApoA-1 may serve as a practical biomarker to refine post-transplant cardiovascular and graft risk stratification.