Heart-kidney transplant offers superior survival than heart alone

Simultaneous heart and kidney transplantation delivers better survival for dialysis- and nondialysis-dependent recipients up to a glomerular filtration rate (GFR) of approximately 30 mL/min/1.73 m² compared with heart transplantation alone, a study has shown.

However, such benefit comes at the cost of nearly double the risk of kidney allograft loss than contralateral kidney allograft recipients.

Using the United Network for Organ Sharing registry, the authors compared long-term mortality between recipients with kidney dysfunction who underwent heart-kidney transplantation (n= 1,124) and those who had isolated heart transplantation (n=12,415) in the US between 2005 and 2018. Among patients who received heart-kidney transplants, contralateral kidney recipients were compared for allograft loss. Finally, the authors used multivariable Cox regression for risk adjustment.

Heart-kidney recipients had lower long-term (5 years) mortality than heart-alone recipients when recipients were on dialysis (26.7 percent vs 38.6 percent; hazard ratio [HR], 0.72, 95 percent confidence interval [CI], 0.58‒0.89) or had GFR of <30 mL/min/1.73 m² (19.3 percent vs 32.4 percent; HR, 0.62, 95 percent CI, 0.46‒0.82) and GFR of 30 to 45 mL/min/1.73 m² (16.2 percent vs 24.3 percent; HR, 0.68, 95 percent CI, 0.48‒0.97), but not in GFR of 45 to 60 mL/min/1.73 m².

On interaction analysis, the mortality benefit with heart-kidney transplantation persisted up to GFR 40 mL/min/1.73 m².

Notably, heart-kidney recipients were more likely to experience kidney allograft loss than contralateral kidney recipients (14.7 percent vs 4.5 percent at 1 year; HR, 1.7, 95 percent CI, 1.4‒2.1).

“Simultaneous heart-kidney transplantation has been increasingly performed in end-stage heart failure patients with concurrent kidney dysfunction despite limited evidence supporting its indications and utility,” the authors said.