In Reply to "Letter Regarding 'Cardiac Outcomes in Isolated Heart and Simultaneous Kidney and Heart Transplants in the United States'".

The Authors Reply:

We thank Dr. Okumura et al. for their interest in our study on outcomes in simultaneous kidney and heart transplants in the United States. We appreciate the suggestions on alternate statistical methods and will keep them in mind for future work. On the basis of our current analysis, we found a survival advantage of simultaneous kidney-heart transplants over heart transplant alone in the subgroup of patients who were on dialysis and those not on dialysis with an estimated glomerular filtration rate < 45 ml/min. This effect was found for the entire cohort of recipients from October 1, 1987, to September 30, 2019, as opposed to the authors’ limited cohort (recipients between 2015 and 2020). Our results are also consistent with previous studies by Karamlou et al. and Habib et al.

Furthermore, when we stratified our cohort according to eras, 1987 to 2007 and 2008 to 2019, we did find a significant improvement in the overall patient and graft survival of heart transplant alone recipients. This is consistent with recently published 30-year trends in heart transplantation. The simultaneous kidney-heart transplant recipients did not have similar improvement between eras (Supplementary Figures 1 and 2). Therefore, the improved survival of heart transplant alone recipients as noted by the authors could be because of a limited cohort in 2015 to 2020, limited follow-up on patients transplanted during this recent period, and overall national improvement in heart transplant outcomes.

We agree with the authors on the need for further analysis, including further substratification based on the year of transplant and donor/recipient characteristics. This will add to the current literature.

Disclosure

All the authors declared no competing interests.