Renal Outcomes in Patients Bridged to Heart Transplant With a Left Ventricular Assist Device

Evaluation and Management of Kidney Dysfunction in Advanced Heart Failure: A Scientific Statement From the American Heart Association

Early identification of kidney dysfunction in patients with advanced heart failure is crucial for timely interventions. In addition to elevations in serum creatinine, kidney dysfunction encompasses inadequate maintenance of sodium and volume homeostasis, retention of uremic solutes, and disrupted endocrine functions. Hemodynamic derangements and maladaptive neurohormonal upregulations contribute to fluctuations in kidney indices and electrolytes that may recover with guideline-directed medical therapy. Quantifying the extent of underlying irreversible intrinsic kidney disease is crucial in predicting whether optimization of congestion and guideline-directed medical therapy can stabilize kidney function. This scientific statement focuses on clinical management of patients experiencing kidney dysfunction through the trajectory of advanced heart failure, with specific focus on (1) the conceptual framework for appropriate evaluation of kidney dysfunction within the context of clinical trajectories in advanced heart failure, including in the consideration of advanced heart failure therapies; (2) preoperative, perioperative, and postoperative approaches to evaluation and management of kidney disease for advanced surgical therapies (durable left ventricular assist device/heart transplantation) and kidney replacement therapies; and (3) the key concepts in palliative care and decision-making processes unique to individuals with concomitant advanced heart failure and kidney disease.

Induction Immunosuppression and Renal Outcomes in Adult Heart Transplantation

BACKGROUND

This study explores the use of induction therapy in orthotopic heart transplantation as it relates to preoperative renal function and evaluates the impact of its utilization on post-transplant outcomes.

METHODS

We conducted a retrospective analysis using the United Network for Organ Sharing database from 2000 to 2018 evaluating the initiation of de novo dialysis after transplantation. We examined the relationship between induction immunosuppression and pre-transplant estimated glomerular filtration rate with post-transplant outcomes, accounting for inter-center variability through a mixed-effects logistic regression model.

RESULTS

In total, 16,201 patients were included with a median age of 57 y (interquartile range 47, 63); 26% were women (n = 4222) and 28% (n = 4552) had a history of diabetes mellitus. The median estimated glomerular filtration rate (eGFR) was 67.5 mL/min (interquartile range 53.1, 86.7); 51.2% (n = 3068) of the recipients with eGFR < 60 received induction therapy compared to 42.5% (n = 4336) within the eGFR ≥ 60 group (P < 0.001). Adjusted multivariable analysis found that induction therapy was associated with de novo dialysis (odds ratio 1.25, 95% confidence interval 1.10-1.43, P < 0.001), with the most significant effect on patients with eGFR ≥ 60. Although significant, there was a weak correlation between center-level induction utilization and mean eGFR (r = -0.2, P < 0.001).

CONCLUSION

In this analysis, the use of induction immunosuppression in orthotopic heart transplantation varied widely between centers and did not correlate strongly with pre-transplant eGFR. In addition, its utilization did not mitigate the risk of renal replacement therapy after transplantation and in fact was associated with increased risk even after adjusting for confounders most notably in patients with eGFR ≥ 60.

Renal Function in Patients with or without a Left Ventricular Assist Device Implant During Listing for a Heart Transplant

Background

Left ventricular assist device (LVAD) implantation may improve kidney function, but in patients awaiting heart transplantation, the long-term effects of LVAD implantation on renal function and subsequent clinical outcome are unclear.

Material/Methods

We analyzed data in patients with LVAD implants (n=139) and without LVAD implants (n=1038) who were listed for a heart transplant at our institution between 2000 and 2019. The primary endpoint was an impairment in renal function (decrease of creatinine-based estimated glomerular filtration rate [eGFR] by ≥30%) up to a maximum of 2 years after listing. Secondary endpoints were chronic kidney disease stage 4 or 5, heart transplantation, survival during listing, and 1-year survival after transplantation.

Results

Values for eGFR increased after LVAD implantation (P=0.001) and were higher at the time of waitlisting in the LVAD group than in the non-LVAD group (P=0.002), but were similar between groups at the end of waitlisting (P=0.75). Two-year freedom from renal impairment was 50.6% and 66.7% in the LVAD and non-LVAD groups, respectively, with a multivariable-adjusted hazard ratio for the LVAD versus the non-LVAD group of 1.78 (95% confidence interval 1.19–2.68; P=0.005). Two-year freedom from chronic kidney disease stages 4–5 was similar between study groups (LVAD group: 83.5%; non-LVAD group: 80.1%; =0.50). The 2-year probability of transplantation was slightly lower in the LVAD group than in the non-LVAD group (50.0% and 55.8%, respectively, P=0.017). However, 2-year survival on the waiting list and 1-year survival after transplantation did not differ significantly between study groups (P-values >0.20).

Conclusions

Our data indicate a transient improvement in creatinine-based eGFR values by LVAD implantation without influencing survival.