SAFETY OF LOW DOSE ACE INHIBITION IN LIVING KIDNEY DONORS : A PILOT STUDY

Introduction:

Glomerular filtration rate (GFR) and cardiovascular risk are inversely correlated. Lower GFR is associated with higher aortic stiffness and endothelial dysfunction. Vascular stiffness in living kidney donors rises after donation. There is concern that living kidney donors may be adversely affected as a result of lower GFR following nephrectomy. ACE inhibitor (ACEi) medications have positive effects on vascular stiffness separate from their anti-hypertensive effects. We evaluated the safety of low dose ACEi, Ramipril 1.25mg, in kidney donors and impact on flow mediated dilatation (FMD) and aortic stiffness at 6 months post donation.

Methods:

In a single centre, open label, randomised control trial, prospective living renal donors between 18-60 years, with no underlying hypertension or allergy to ACEi were enrolled. eGFR, pulse wave velocity (PVW) and FMD were recorded at baseline and subjects were randomized (1:1 ratio) at the time of discharge to receive either daily dose of 1.25 mg of Ramipril or no medication. All subjects underwent repeat measurement of FMD, PWV and eGFR at 6 months after kidney donation. Subjects were withdrawn from the study during follow up if serum creatinine increased by >25% as compared to baseline, or serum potassium rose to >5.5 mEq/L, or systolic blood pressure (SBP) fell to <90 mmHg or fell by >25% as compared to baseline. Continuous variables were compared between groups by independent samples paired t test. Categorical variables were analyzed by Chi-square test.

Results:

Out of 75 participants screened, 59 were enrolled and underwent donor nephrectomy and subsequent randomization. 29 participants were allocated to the Intervention/Ramipril arm, 30 participants were allocated to Control arm. At the end of 6 month, 19 participants completed follow up in the intervention arm and 23 subjects in the control arm (Figure 1). Only one participant in intervention arm (3.44%) developed side effect in the form of increase in serum creatinine to >25% from baseline. None of the participants in intervention arm developed a fall in SBP or rise in serum potassium. In the control arm, 2 (6.7%) participants had a rise in serum creatinine. There were no trends to suggest that complications like hypotension, hyperkalemia or elevation in serum creatinine were higher in the intervention group as compared to the control group. Mean difference in eGFR (pre and post donation) was 25.4±16.3ml/min/1.73m2 in intervention arm while 26.0±17.1ml/min/1.73m2 in the control arm (p=0.909). The mean difference in FMD at 6 months vs baseline in intervention arm was 3.63±10.76% while in control arm was -2.62±10.28% (p=0.098). Similarly, there was no significant difference at 6 months post donation in PWV between the intervention and control arm. 

Conclusions:

Use of ramipril in dose of 1.25 mg once every day in living kidney donors was safe. There were differences in vascular function parameters between the groups but that did not reach statistical significance. This is likely due to limited sample size in pilot phase.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.