Utility of 24-hour ambulatory blood pressure monitoring in potential living kidney donors.

Introduction: Hypertension (HTN) is a risk factor for cardiovascular disease; therefore, it is imperative to risk stratify potential kidney donors during evaluation. Clinic blood pressure (CBP) measurement is inaccurate in assessing presence or absence of HTN. There is paucity of data about utility of 24-h ambulatory blood pressure monitoring (ABPM) during kidney donor evaluation.

Methods: 24-h ABPM is performed on all kidney donors at Mayo Clinic Florida. We conducted retrospective review of 264 consecutive potential kidney donors from 1/1/2012 to 12/31/2017. Demographic, comorbid conditions, laboratory results and 24-h ABPM data were collected. Subjects were divided into two groups: Group1: Subjects with no prior history of HTN and new diagnosis of HTN using 24-h ABPM; Group 2: Subjects with no prior history of hypertension and normal BP on 24-h ABPM.

Results: Baseline demographic included mean age 46.40 years, 39% males, 78.4% Caucasians, and mean BMI was 26.94. Twenty one subjects (8.0%) had prior diagnosis of HTN. Among 243 subjects without prior HTN, 62 (25.5%) were newly diagnosed with HTN using 24-h ABPM. CBP was high only in 27 out of 62 (43.6%) of newly diagnosed HTN subjects. Thirty-five subjects (14.4%) had masked HTN and 14 subjects (5.8%) had white-coat HTN. Newly diagnosed hypertensive subjects were more likely to be males as compared to Group 2 (53.2% vs 34.3% P = 0.008). There was a trend of more non-Caucasians subjects (30.6% vs 19.9% P = 0.08) and more active smokers (17.7% vs 11.6%, P = 0.054) in Group1 as compared to Group 2. Only 17 (27.4%) out of 62 newly diagnosed hypertensive subjects were deemed suitable for kidney donation as compared to 105 (58.0%) out of 181 normotensive subjects (P < 0.001).

Conclusion: In our cohort, use of ABPM resulted in new diagnosis of HTN in 1 out of 4 potential kidney donors. Newly diagnosed HTN was more common in men, those with non-Caucasian race, and in active smokers. There was a significantly reduced acceptance rate for kidney donation among newly diagnosed HTN subjects. Further studies are needed to determine the value of 24-h ABPM among these high risk groups.