The following is a summary of “Outcomes of Simultaneous Heart and Kidney Transplantation,” published in the February 2023 issue of Cardiology by Itagaki, et al.

Although limited evidence supports simultaneous heart-kidney transplantation, it has become increasingly common in patients with both end-stage heart failure and kidney dysfunction. This study aimed to assess the effects and usefulness of simultaneously implanted kidney allografts with varying degrees of kidney dysfunction during heart transplantation.

The United Network for Organ Sharing registry was used to compare the long-term mortality of recipients with kidney dysfunction who underwent heart-kidney transplantation (n = 1,124) to those who received only heart transplantation (n = 12,415) between 2005 and 2018 in the United States. For heart-kidney recipients, the rate of allograft loss was compared with that of contralateral kidney recipients. Multivariable Cox regression was used to adjust for risks.

The results showed that heart-kidney recipients had lower long-term mortality rates than heart-alone recipients when recipients were on dialysis (26.7% vs 38.6% at 5 years; HR: 0.72; 95% CI: 0.58-0.89), or had a glomerular filtration rate (GFR) of less than 30 mL/min/1.73 m² (19.3% vs 32.4%; HR: 0.62; 95% CI: 0.46-0.82) and GFR of 30 to 45 mL/min/1.73 m² (16.2% vs 24.3%; HR: 0.68; 95% CI: 0.48-0.97), but not in the case of GFR of 45 to 60 mL/min/1.73 m2. The interaction analysis revealed that the benefit of heart-kidney transplantation continued up to GFR 40 mL/min/1.73 m². The study also found that the incidence of kidney allograft loss was higher among heart-kidney recipients than contralateral kidney recipients (14.7% vs 4.5% at 1 year; HR: 1.7; 95% CI: 1.4-2.1).

In conclusion, heart-kidney transplantation was found to provide better long-term survival for dialysis-dependent and non-dialysis-dependent recipients with a GFR of approximately 40 mL/min/1.73 m2, but at the cost of a higher risk of kidney allograft loss compared to contralateral kidney allograft recipients.

Reference: jacc.org/doi/10.1016/j.jacc.2022.11.053