Pre-transplant Proteinuria is a Risk Factor for Worsening Renal Function in Heart Transplant Candidates

摘要

BackgroundProteinuria has recently emerged as an independent risk factor for post-implant renal failure and mortality in patients undergoing continuous-flow left ventricular assist device implantation. Impact of proteinuria on heart transplant outcomes remains unknown. We hypothesized that end-stage heart failure patients with proteinuria have increased risk of renal failure and mortality following cardiac transplantation. MethodsPatients who underwent orthotopic heart transplantation (OHT) at a major academic center between 2000 and 2016 were retrospectively reviewed. Urine protein was qualitatively assessed by dipstick test. Patients were categorized into proteinuria (≥ trace) or no proteinuria groups. Groups were comparatively analyzed for baseline recipient and donor characteristics. Outcomes measures included freedom from post-transplant renal failure which was defined as serum creatinine ≥ 2.5 mg/dL, and post-transplant patient survival. Results195 out of 656 (26.7%) patients had evidence of proteinuria (≥ trace) at the time of cardiac transplantation. Of these, 93 (12.7%) had trace, 72 (9.8%) had 1+, 30 (4.1%) had 2+ or greater proteinuria. Patients with proteinuria (≥ trace) were younger (53.7 ± 12.3 vs. 50.6 ± 13.4 years, p=0.005), had higher serum creatinine (1.46 ± 0.78 vs. 1.32 ± 0.55 mg/dL, p=0.037), and lower serum albumin (3.81 ± 0.57 vs. 4.00 ± 0.52 g/dL, p<0.001) compared to patients without proteinuria. Ischemic time (3.2 ± 0.99 vs. 3.24 ± 1.02 hours, p=0.635) and donor age (34.2 ± 13.1 vs. 33.5 ± 12.7 years, p=0.503) were comparable between the two groups. Patients with proteinuria had lower freedom from renal failure at 1-year (57.5% vs. 65.8%) and at 2-years (54.4% vs. 60.6%) following heart transplantation compared to patients without proteinuria (log-rank p=0.011) (FIGURE). Post-transplant mortality was comparable between the two groups (83.4% vs. 85.8% at 2 years, p=0.781) (FIGURE). ConclusionsOne in every four patients undergoing cardiac transplantation have evidence for proteinuria. Proteinuria is a risk factor for worsening renal function following cardiac transplantation but does not have a significant impact on post-transplant mortality. Proteinuria should be routinely assessed in transplant recipients and taken under consideration for individualization of immunosuppressive management in order to achieve optimal patient outcomes.