Simultaneous Heart-Kidney Transplant Compared to Heart Transplant Alone in Non-Dialysis Dependent Patients with Borderline Renal Function.

OBJECTIVE: This study assessed characteristics and outcomes of non-dialysis dependent patients receiving simultaneous heart kidney (SHK) transplantation versus heart transplantation alone (HTA) to identify optimal eGFR threshold where combined transplant strategy may be superior.

METHODS: This study retrospectively analyzed 7896 adult patients with estimated glomerular filtration rate (eGFR) < 60 mL/min from the United Network for Organ Sharing (UNOS) database who received HTA or SHK between 2005 and 2021, excluding those who received pre-transplant dialysis. Subjects were further stratified into three groups based on CKD stage at time of transplant: Stage 3A (eGFR 45-59 mL/min, n=5044), Stage 3B (eGFR 30-44 mL/min, n=2193), and Stage 4-5 (eGFR < 30 mL/min, n=659). Outcomes of interest were all-cause mortality, cardiac allograft failure, and freedom from chronic dialysis or renal transplant following heart transplant.

RESULTS: SHK and HTA recipients differed in various baseline characteristics. SHK recipients with eGFR < 45 mL/min had greater short- and long-term overall survival and cardiac allograft survival compared to HTA, as well as greater long-term freedom from chronic dialysis or renal transplant. These results were consistent with both propensity matched analyses and multivariable Cox regression analysis of 10 year outcomes. Optimal cutoff value for pre-transplant eGFR in predicting elevated risk of renal failure in recipients of heart transplant alone was found to be eGFR ∼45 mL/min.

CONCLUSION: Similar to patients with eGFR < 30 mL/min, patients with eGFR 30-44 mL/min who underwent SHK had superior outcomes compared to HTA, suggesting possible benefit of combined transplant strategy for this subset of heart transplant candidates.