Pre-orthotopic heart transplant estimated glomerular filtration rate predicts post-transplant mortality and renal outcomes: An analysis of the UNOS database

Abstract

Background: Pre-orthotopic heart (OHT) serum creatinine correlates with post-OHT outcomes, but there is limited information on the relationship between pre-OHT estimated glomerular filtration rate (eGFR) and adjusted short- and long-term survival and renal outcomes post-OHT.

Methods: Using the United Network of Organ Sharing (UNOS) database we estimated pre-OHT eGFR using the Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in patients aged ≥18 years who underwent OHT between 1988 and 2013. Patients were stratified into 5 eGFR categories (≥90, 60 to 89, 45 to 59, 30 to 44 and <30 ml/min/1.73 m²) using each equation. The primary outcome was to determine whether pre-OHT eGFR independently predicted post-OHT mortality.

Results: A total of 30,090 patients were included in the study; of these, 46.1% and 39.9% had an eGFR <60 ml/min/1.73 m² by MDRD and CKD-EPI, respectively. Compared with eGFR ≥90 ml/min/1.73 m², the adjusted hazard ratio of mortality was 1.09 (95% confidence interval [CI] 1.02 to 1.26) for eGFR 45 to 59 ml/min/1.73 m², 1.22 (95% CI -1.23 to 1.31) for eGFR 30 to 44 ml/min/1.73 m² and 1.55 (95% CI 1.41 to 1.70) for eGFR <30 ml/min/1.73 m² by MDRD. There was no advantage for CKD-EPI over MDRD in determining post-OHT mortality. Pre-OHT eGFR by either equation was predictive of post-OHT end-stage renal disease (ESRD) and the need for kidney transplantation, with the highest risk in those with pre-OHT eGFR <30 ml/min/1.73 m² by either equation.

Conclusions: Pre-OHT eGFR was independently associated with mortality, ESRD and kidney transplantation after OHT. There was no advantage of CKD-EPI over MDRD in determining post-OHT mortality or renal outcomes.

Keywords: creatinine based GFR estimation; estimated glomerular filtration rate; heart transplant outcome; kidney function after heart transplantation; pre–heart transplant kidney function.