Impact of changing renal function, while waiting for a heart transplant, on post-transplant mortality and development of end stage kidney disease

Simultaneous heart-kidney transplant compared with heart transplant alone in patients with borderline renal function who are not dialysis dependent

OBJECTIVE

This study assessed characteristics and outcomes of patients who are not dependent on dialysis receiving simultaneous heart kidney 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/minute from the United Network for Organ Sharing database who received HTA or simultaneous heart kidney transplant between 2005 and 2021, excluding those who received pretransplant dialysis. Subjects were further stratified into 3 groups based on chronic kidney disease stage at time of transplant: Stage 3A (eGFR 45-59 mL/minute; n = 5044), Stage 3B (eGFR 30-44 mL/minute; n = 2193), and Stage 4 or 5 (eGFR <30 mL/minute; n = 659). Outcomes of interest were all-cause mortality, cardiac allograft failure, and freedom from chronic dialysis or renal transplant following heart transplant.

RESULTS

Simultaneous heart kidney transplant and HTA recipients differed in various baseline characteristics. Simultaneous heart kidney transplant recipients with eGFR <45 mL/minute had greater short- and long-term overall survival and cardiac allograft survival compared with 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 pretransplant eGFR in predicting elevated risk of renal failure in recipients of heart transplant alone was found to be eGFR ∼45 mL/minute.

CONCLUSIONS

Similar to patients with eGFR <30 mL/minute, patients with eGFR 30 to 44 mL/minute who underwent simultaneous heart kidney transplant had superior outcomes compared with HTA, suggesting possible benefit of combined transplant strategy for this subset of heart transplant candidates.

The Year in Cardiothoracic Transplant Anesthesia: Selected Highlights From 2021 Part II: Cardiac Transplantation

This article spotlights the research highlights of this year that specifically pertain to the specialty of anesthesia for heart transplantation. This includes the research on recent developments in the selection and optimization of donors and recipients, including the use of donation after cardiorespiratory death and extended criteria donors, the use of mechanical circulatory support and nonmechanical circulatory support as bridges to transplantation, the effect of COVID-19 on heart transplantation candidates and recipients, and new advances in the perioperative management of these patients, including the use of echocardiography and postoperative outcomes, focusing on renal and cerebral outcomes.

Recent Developments in the Evaluation and Management of Cardiorenal Syndrome: A Comprehensive Review

Cardiorenal syndrome (CRS) is an increasingly recognized diagnostic entity associated with high morbidity and mortality among acutely ill heart failure (HF) patients with acute and/ or chronic kidney diseases (CKD). While traditionally viewed as a state of decline in glomerular filtration rate (GFR) due to decreased renal perfusion, mainly due to therapeutic interventions to relieve congestive in HF, recent insights into the underlying pathophysiologic mechanisms of CRS led to a broader definition and further classification of CRS into 5 distinct types. In this comprehensive review, we discuss the classification of CRS, highlighting the underlying common pathogenetic pathways of heart failure and kidney injury, including increased congestion, neurohormonal dysregulation, oxidative stress as well as inflammation, and cytokine storm that are particularly evident in COVID-19 patients with multiorgan failure and also in those with other disorders including sepsis, systemic lupus erythematosus and amyloidosis. In this review we also present the recent advances in the diagnostic strategies of CRS including cardiac and renal biomarkers as well as advanced cardiac and renal imaging techniques that are available to aid in the diagnosis as well as in the prognostication of this disorder. Finally, we discuss the various therapeutic options available to-date, including fluid optimization, hemofiltration, renal replacement therapy as well as the role of SGLT2 inhibitors in light of recent data from RCTs. It is important to note that, CRS population are either excluded or underrepresented, at best, in major RCTs and therefore, therapeutic recommendations are largely extrapolated from HF and CKD clinical trials.

Overcoming challenges in patient selection and monitoring in combined heart and kidney transplantation

Combined heart-kidney transplantation (HKT) is a growing therapeutic strategy in patients with advanced heart failure (HF) and concomitant chronic kidney disease (CKD). Although patients with advanced HF and need for chronic haemodialysis have a clear indication for combined HKT, challenges to current practice lie in identifying those patients with severely depressed kidney function, which will not recover kidney function after restoration of appropriate haemodynamic conditions following heart transplantation (HT) alone. Because of the paucity of available organs, maximisation of kidney graft utility whilst minimising the operative risks associated with combined transplantation is mandatory. The benefits of HKT go beyond the mere restoration of kidney function. Data from registry analysis show that HKT improves overall survival in patients with CKD, as compared to heart transplant only, and it is associated with reduced incidence of heart allograft rejection, likely through the promotion of host immune tolerance mechanisms. In patients not requiring chronic dialysis, kidney-after-heart strategy may be explored, instead of combined HKT, in particular when the aetiology of CKD is unclear. This indeed allows for monitoring and gaging of indications for combined transplantation in the postoperative period. This approach however should be matched with priority listing for kidney transplantation given the high waitlist mortality in heart transplant recipients with associated CKD. The use of kidney machine perfusion may represent an additional tool to optimise the outcome of HKT, allowing more time to stabilise the patient after HT surgery.