Endovascular Ultrasound Renal Denervation to Lower Blood Pressure in Young Hypertensive Women Planning Pregnancy: Study Protocol for a Multicentre Randomised, Blinded and Sham Controlled Proof of Concept Study

Introduction: A major issue confronting clinicians treating hypertension in pregnancy is the limited number of pharmacological options. Endovascular catheter-based renal denervation (RDN) is a new method to lower blood pressure (BP) in patients with hypertension by reducing the activity of the renal sympathetic nervous system. Drugs that affect this system are safe in pregnant women. So there is reasonable evidence that RDN performed before pregnancy should not have deleterious effects for the fetus. Because the efficacy of RDN may be greater in younger patients and in women, we may expect a larger proportion of BP normalisation in young hypertensive women, but this remains to be proven. Our primary objective is to quantify the proportion of BP normalisation with RDN in this population.

Methods And Analysis: WHY-RDN is a multicentre randomised sham-controlled trial conducted in six French hypertension centres that will include 80 women with essential hypertension treated or untreated, who are planning a pregnancy in the next 2 years and will be randomly assigned to RDN or classic renal arteriography and sham RDN in a ratio of 1:1. The primary outcome is the normalisation of 24-hour BP (<130/80 mm Hg) at 2-month post procedure off treatment. Sample size is calculated with the following assumptions: 5% one-sided significance level (α), 80% power (1-β), expected responder rates of 24% and 3% in the treatment and control group, respectively. Secondary outcomes include the absence of adverse outcomes for a future pregnancy, the variations of BP in ambulatory and home BP measurements and the evaluation of treatment prescribed.

Ethics And Dissemination: WHY-RDN has been approved by the French Ethics Committee (Tours, Region Centre, Ouest 1- number 2021T1-28 HPS). This project is being carried out in accordance with national and international guidelines. The findings of this study will be disseminated by publication.

Trial Registration Number: ClinicalTrials.gov, NCT05563337.