Endpoint design for future renal denervation trials - Novel implications for a new definition of treatment response to renal denervation

BackgroundDefining an adequate endpoint for renal denervation trials represents a major challenge. A high inter-individual and intra-individual variability of blood pressure levels as well as a partial or total non-adherence on antihypertensive drugs hamper treatment evaluations after renal denervation. Blood pressure measurements at a single point in time as used as primary endpoint in most clinical trials on renal denervation, might not be sufficient to discriminate between patients who do or do not respond to renal denervation.MethodsWe compared the traditional responder classification (defined as systolic 24-hour blood pressure reduction of − 5 mm Hg six months after renal denervation) with a novel definition of an ideal respondership (based on a 24 h blood pressure reduction at no point in time, one, or all follow-up timepoints).ResultsWe were able to re-classify almost a quarter of patients. Blood pressure variability was substantial in patients traditionally defined as responders. On the other hand, our novel classification of an ideal respondership seems to be clinically superior in discriminating sustained from pseudo-response to renal denervation.ConclusionBased on our observations, we recommend that the traditional response classification should be reconsidered and possibly strengthened by using a composite endpoint of 24 h-BP reductions at different follow-up-visits.