Cardiovascular and kidney outcomes of living kidney donors with preexisting hypertension: A systematic review and meta-analysis

Abstract Introduction 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 pre-existing hypertension. Methods We performed a systematic search across MEDLINE, EMBASE, Cochrane CENTRAL, and EBM databases up to October 1, 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/1.73m² 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, RD) for mortality, MACE, kidney failure, and eGFR ≤ 45 mL/min/1.73m² 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 1000 person years , 95% CI 4.0, 70.0 ; p=0.03), but no significant differences in kidney failure (RD 1.0 per 1000 person years , 95% CI (0.3, 2.6); p=0.13), eGFR ≤ 45 mL/min/1.73m² (RD 20.0 per 1000 person years, 95% CI -90.0, 140.0; p=0.69), or MACE (RD 3.0 per 1000 person years, 95% CI -90.0, 160.0; p=0.58). Conclusion 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.