12th Biennial Meeting of the International Andreas Gruentzig Society: Rio de Janeiro - February 2-6, 2014
From SESSION 9: Emerging Therapies
Moderator: Dennis Goodman
Panelists: Dieter Liermann, Jeff Marshall, Klaus Mathias, Brian O’Murchu, Souheil Saddekni, Richard Shaw, Jim Zidar
Framing the question at hand, what is the state of the current knowledge?
More than 77 million Americans and one billion adults worldwide are affected by HTN and its associated risk of heart attack and stroke. About 13% of patients with HTN are considered to be treatment resistant despite taking a 3 drug regimen that includes a diuretic. Catheter based renal denervation appeared to offer real hope for these patients when SYMPLICITY 2 trial results were published in Nov 2010 but these hopes were dashed with results from SYMPLICITY HTN 3 being announced at ACC.2014 in Washington. 535 patients with resistant HTN and systolic BP of 160 mmHg or higher were randomized to renal denervation or angiography alone — both blinded and sham controlled. The study failed to reach its primary efficacy endpoint at 6 months with only a 2.29 mmHg difference (NS) between 2 groups. This disappointing result left many experts wondering if renal denervation techniques should be abandoned.
What are the Gaps in the current knowledge?
Many questions have arisen since the SYMPLICITY 3 results were announced. Do we really understand how it works? How do we measure success at time of procedure? How do we measure sympathetic tone? Do we know which patients will benefit most? Is re-inervation of the denervated renal artery a potential limiting factor? Are we looking at right endpoints and are there possible long-term benefits that we may be missing?
Our Summary and Recommendations:
One strong possibility for the negative trial results is that we do not know whether successful denervation was achieved at the time of the procedure. We need to find a measure of sympathetic tone and to develop devices that will be effective in achieving renal denervation at time of procedure.
Further research is needed and we strongly urge further evaluation in rigorously designed clinical trials.