The decline in kidney function after heart transplantation and its impact on survival

Evidence of decline in native renal function after heart transplantation (HTx) in the Asian population is limited. This study determined the incidence and risk factors associated with declining kidney function after HTx and its impact on survival.

A retrospective study of consecutive adult heart transplant patients was conducted in a single center between 2010 and 2020. The decline in kidney function was defined as the presence of one of the following criteria, including a ≥ 40% decline in eGFR, absolute value <15 mL/min/1.73 m² (calculated by the CKD-EPI method), doubling of serum creatinine, or dialysis.

A total of 79 patients (77% male, mean age 44.5 ± 11.53 years, with a mean eGFR at discharge from the heart transplant admission of 87.9 ± 25.48 mL/min/1.73 m² ) were included. During the median follow-up of 42 months, the rate of decline in eGFR was 3.9 mL/min/1.73 m² per year, with a cumulative probability of decline in kidney function of 22% at 1 year and 43% at 5 years. The need for dialysis was 2.5% at 1 year and 5% at 5 years. The decline in kidney function within 1 year after discharge (hazard ratio (HR), 22.24; p = .007) and pre-HTx diabetes mellitus (DM) (HR, 8.99; p = .034) were independently associated with the need for dialysis. Post-HTx dialysis predicted all-cause mortality (HR, 4.47; p = .017).

Approximately 20% of HTx patients developed a decline in kidney function within 1 year after discharge. These individuals and pre-HTx DM patients needed preventive measures to prevent progression to chronic dialysis, which impacted survival. (thaiclinicaltrials.org number, TCTR20230620004).