The Impact of Renal Dysfunction in Mechanical Circulatory Support Device Patients on Post-Heart Transplant Outcomes

Purpose Patients with severe heart failure who have undergone placement of a mechanical circulatory support (MCS) device do develop renal dysfunction. This renal dysfunction is not severe enough to necessitate the use of combined heart transplantation (HTx) and kidney transplantation. However, it has not been firmly established whether kidney dysfunction does add to increased morbidity or mortality after HTx in these device patients. Methods Between 2012 and 2019, we assessed 79 patients who have undergone MCS, either with total artificial heart (n=22) or left ventricular assist device (n=53). Baseline creatinine/glomerular filtration rate (GFR) was measured and patients were divided into GFR categories which include 30-39 mL/min, 40-49 mL/min, 50-59 mL/min, and greater than or equal to 60 mL/min. All patients underwent HTx alone. The need for temporary dialysis was recorded, as well as peak creatinine in the first 3 months after HTx and serum creatinine at 1 year compared to baseline. Further outcomes include subsequent 1-year survival, freedom from cardiac allograft vasculopathy (CAV, stenosis ≥30%), and freedom from non-fatal major adverse cardiac event (NF-MACE: myocardial infarction, new congestive heart failure, percutaneous coronary intervention, implantable cardioverter defibrillator/pacemaker implant, stroke). Results There was no significant difference in 1-year survival, CAV, and NF-MACE or the need for temporary dialysis amongst all groups. Furthermore, no patient in any group needed chronic dialysis. In the GFR 40-49 group compared to the other groups, there was a trend for higher creatinine at 1 year but the baseline was high. Conclusion Baseline lower GFRs between 30-39 and 40-49 mL/min in MCS patients do not appear to be a predictor of poorer outcomes after HTx in patients. These patients do not appear to require combined heart and kidney transplantation.