Cardiovascular and Kidney Outcomes of Living Kidney Donors With Preexisting Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND: As the demand for living donor kidney transplantation increases, transplant programs have increasingly accepted hypertensive kidney donors. However, the safety of this practice remains unclear. This systematic review and meta-analysis aims to evaluate cardiovascular and kidney outcomes in living kidney donors with and without preexisting hypertension. METHODS: We performed a systematic search across MEDLINE, EMBASE, Cochrane CENTRAL, and EBM databases up to 1 October 2024. The exposure group consisted of living kidney donors with hypertension, while the comparator group included those without hypertension. Primary outcomes included differences in survival, major adverse cardiovascular events (MACE), estimated glomerular filtration rate (eGFR) of 45 mL/min/1.73 m² or less, and development of kidney failure, defined as requiring dialysis or a transplant. Risk differences (proportion of participants experiencing the outcome in the hypertensive group minus the proportion in the normotensive group, risk difference) for mortality, MACE, kidney failure, and eGFR ≤ 45 mL/min/1.73 m² were pooled for synthesis. RESULTS: Of the 983 studies screened, 17 were included, totaling 4,881 hypertensive and 40,565 normotensive kidney donors. The mean (SD) age at donation was 48.9 (18.1) years, with a median (IQR) follow-up of 5.0 (2.0-7.1) years. Hypertensive donors showed a significantly higher risk of death (RD 40.0 per 1,000 person years, 95% confidence interval (CI) 4.0, 70.0; P = 0.03), but no significant differences in kidney failure (RD 1.0 per 1,000 person years, 95% CI (0.3, 2.6); P = 0.13), eGFR ≤ 45 mL/min/1.73 m² (RD 20.0 per 1,000 person years, 95% CI, -90.0, 140.0; P = 0.69), or MACE (RD 3.0 per 1,000 person years, 95% CI, -90.0, 160.0; P = 0.58). CONCLUSIONS: This review suggests that hypertensive living kidney donors have a higher risk of death compared to normotensive donors, but no increased risk for kidney failure, low eGFR, or MACE. However, further long-term studies are needed, particularly for younger hypertensive donors.