Contribution of impaired renal function to cardiovascular risk prediction models in renal transplant recipients

Abstract

Background: The Framingham risk score (FRS) and cardiovascular risk calculator for renal transplant recipients (CRCRTR-MACE) quantify cardiovascular risk in renal transplant recipients (RTR). In contrast to the FRS, the CRCRTR-MACE includes serum creatinine as a variable in the risk prediction equation.

Objective: To determine the influence of impaired renal function on performances of the two equations.

Methods: A chart review of 270 RTR transplanted from 1979 to 2012. High risk was defined at scores ≥20%. Standard statistical analyses included multivariate analysis (MVA), stepwise analysis, and odds ratio to estimate contributions of risk factors.

Results: Mean transplant duration was 9.51 ± 6.65 yr. Mean eGFR was 59.19 ± 28.26 mL/min/1.73 m(2) . FRS and CRCRTR-MACE scores of least 20% were present in 9.3% and 24.8%, respectively, while 7.2% and 11.2% of RTR with eGFR ≥60 mL/min/1.73 m(2) were high risk, respectively. Mean age, blood pressure, TC:HDL ratio, smoking, and diabetes were evenly distributed in patients with varying eGFR. FRS scores remained similar at wide eGFR range (≤30 mL/min/1.73 m(2) -≥90 mL/min/1.73 m(2) ), while CRCRTR-MACE scores significantly increased as eGFR decreased.

Conclusions: CRCRTR-MACE identified more patients at high cardiovascular risk, even in those with more favorable renal function, suggesting a fundamental difference between the two calculators beyond renal function.

Keywords: Framingham risk score; GFR; MACE; cardiovascular events; cardiovascular risk factors; kidney transplantation.