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

International journal of cardiology

PubMedID: 27390940

Lambert T, Nahler A, Rohla M, Reiter C, Grund M, Kammler J, Blessberger H, Kypta A, Kellermair J, Schwarz S, Starnawski JA, Lichtenauer M, Weiss TW, Huber K, Steinwender C. Endpoint design for future renal denervation trials - Novel implications for a new definition of treatment response to renal denervation. Int J Cardiol. 2016;220273-278.
BACKGROUND
Defining 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.

METHODS
We compared the traditional responder classification (defined as systolic 24-hour blood pressure reduction of -5mmHg six months after renal denervation) with a novel definition of an ideal respondership (based on a 24h blood pressure reduction at no point in time, one, or all follow-up timepoints).

RESULTS
We 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.

CONCLUSION
Based on our observations, we recommend that the traditional response classification should be reconsidered and possibly strengthened by using a composite endpoint of 24h-BP reductions at different follow-up-visits.