Association between pre-heart transplant kidney function and post-transplant outcomes in Black and White adults.

BACKGROUND: It remains unknown whether estimated glomerular filtration rate (eGFR) using the refit Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation without a term for race is associated with mortality and the need for kidney replacement therapy (KRT) differentially between Black and White heart transplant recipients.

METHODS: We studied 25,900 adults included in the Scientific Registry of Transplant Recipients. We classified recipients into six categories of eGFR (< 30, 30 to < 45, 45 to < 60, 60 to < 90, 90 to < 120, ≥ 120 ml/min/1.73 m2 ) using the race-neutral CKD-EPI refit equation, and assessed survival with multivariable adjusted Cox proportional hazards regression.

RESULTS: The association between pre-transplant race-neutral eGFR and mortality varied by race (Pinteraction  = 0.006). Compared to White patients with an eGFR of 90-120 ml/min/1.73 m2 , the mortality rates were 57% (95% CI 1.25, 1.98), 29% (95% CI 1.11, 1.51), 34% (95% CI 1.19, 1.52), and 19% (95% CI 1.06, 1.33) higher in Black patients with an eGFR less than 30, 30-45, 45-60, and 60-90 ml/min/1.73m2 , respectively; and 53% (95% CI 1.28, 1.82), 49% (95% CI 1.33, 1.66), and 23% (95% CI 1.11, 1.35) higher among White patients with an eGFR less than 30, 30-45, and 45-60 ml/min/1.73 m2 , respectively. The association between pre-transplant eGFR and the need for KRT during follow-up was similar between Black and White patients (Pinteraction  = 0.57).

CONCLUSIONS: Worsening pre-transplant eGFR using the new race-neutral CKD-EPI refit equation was associated with a higher rate of post-heart transplant mortality and KRT in Black and White recipients. The racial disparity in post-heart transplant mortality was narrower in the setting of severe kidney dysfunction.