Simultaneous heart‐kidney transplant in patients with borderline estimated glomerular filtration rate without dialysis dependency

Abstract

BackgroundAppropriate patient selection for simultaneous heart‐kidney transplantation (sHK) in patients with moderate renal dysfunction remains challenging.MethodsFrom the United Network for Organ Sharing database (2003–2020), we identified 5678 adults with an estimated pre‐transplant glomerular filtration rate (eGFR) between 30 and 45 mL/min/1.73 m2 and no pre‐transplant dialysis. Patients undergoing sHK (n = 293) were compared with those undergoing heart transplantation alone (n = 5385) using 1:3 propensity score matching.ResultsThe sHK utilization rate increased from 1.8% in 2003 to 12.2% in 2020 (p < .001). After matching, 1 and 5‐year survival was 87.7% (95% confidence interval [CI] 83.3–91.0) and 80.0% (95% CI 74.2–84.6) after sHK, and 87.3% (95% CI 85.2–89.1) and 71.8% (95% CI 68.4–74.9) after heart transplant alone (p = .04). In the subgroup analysis, sHK was associated with a 5‐year survival benefit only in patients with 30 < eGFR ≤ 35 mL/min/1.73 m2 (p = .05) but not in those with 35 < eGFR < 45 mL/min/1.73 m2 (p = .45). Patients who underwent heart transplants alone also had a higher incidence of becoming chronic dialysis‐dependent after transplant within 5‐year follow‐up (10.2%, 95% CI 8.0–12.6 vs. 3.8%, 95% CI 1.7–7.1, p = .004). The 5‐year incidence of subsequent kidney waitlisting and transplants after heart transplants alone was 5.6% and 1.9%, respectively.ConclusionAmong propensity‐matched patients without pre‐transplant dialysis, compared to heart transplants alone, sHK had improved 5‐year survival in those with 30 < eGFR ≤ 35 but not in those with 35 < eGFR < 45 mL/min/1.73 m2. One‐year survival was similar irrespective of eGFR. Receiving a kidney after a heart transplant alone is rare under the current allocation system.

Evolutions in Combined Heart-Kidney Transplant

“…However, no survival advantage of SHKT vs HT was conferred in those with eGFR 35–45 mL/min/1.73 mL 2 or higher. Of note, 1-year survival was similar between SHKT and HT alone regardless of eGFR [ 5 ]. Similar findings were observed in another UNOS registry analysis from 2005 to 2018, where those patients on dialysis or with an eGFR of 40 mL/min/1.73 mL 2 or less had improved 5-year survival with SHKT vs HT alone [ 6 •].…”

“…While SHKT improves survival in patients with heart failure and kidney dysfunction compared to heart transplantation (HT) alone, it is by no means a panacea [ 4 , 5 , 6 •, 7 ••]. Post-SHKT, a considerable proportion of patients experience severe acute kidney injury (AKI) requiring dialysis, and/or CKD over the long term, leading to increased post-transplant morbidity and mortality, and SHKT may reduce the lifespan of a kidney allograft [ 6 •, 7 ••, 8 , 9 ].…”