Author + information
- Richard Katholi1,
- Murray Esler2,
- Henry Krum3,
- Krishna Rocha-Singh1,
- Markus Schlaich2,
- Michael Böhm4 and
- Felix Mahfoud4
Treatment resistant hypertension (rHTN) is defined as uncontrolled blood pressure despite use of ≥3 antihypertensive drugs including a diuretic. The sympathetic nervous system plays an important role in the pathogenesis of hypertension. The Symplicity™ renal denervation system uses a percutaneous approach to deliver low-power radiofrequency energy to interrupt the efferent sympathetic and afferent renal nerves. Up to 3 year follow-up of pooled patient level data are available to evaluate renal denervation (RDN) efficacy and safety, including patients with type II diabetes mellitus (DM).
The Symplicity HTN-1 and Symplicity HTN-2 prospective, multicenter trials enrolled rHTN subjects with a systolic BP (SBP) ≥160 mm Hg; (≥150 mm Hg for DM subjects). Subjects remained on their antihypertensive drugs for 6 months after which changes were allowed as clinically indicated. A subset of subjects in Symplicity HTN-1were consented to 3 years; all subjects randomized to immediate RDN on Symplicity HTN-2 were followed to 3 years post-RDN. Change from baseline BP was measured at each follow-up and all safety events were evaluated.
Baseline characteristics of 128 subjects followed through 3 years include mean age, 58 years; 34% DM, 38% female, and body mass index of 32 kg/m2. Mean baseline SBP was 175.7 ± 14.1 mm Hg and was reduced by 24.6 ± 22.7 mm Hg at 6 months (p<0.01). This BP reduction was sustained at 3 years with a mean drop of 32.2 ± 19.7 mm Hg (p<0.01). DM and non-DM subjects had similar baseline SBP and experienced a similar and significant reduction in SBP at 3 years (-30.0 mm Hg vs -33.3 mm Hg, respectively, p<0.001 compared with baseline, p=0.37 between DM and non-DM subjects). Procedure-related adverse events included 2 dissections (1 before radiofrequency energy was delivered), and 1 access site hematoma. Serious adverse events included 6 deaths, 4 renal failure cases (all resolved), and 1 stenosis requiring stenting.
The data indicates that treatment of rHTN with the Symplicity catheter provides safe and sustained reductions in SBP through 3 years. The reduction in SBP was similar in both DM and non DM subjects.
↵∗ Indicates iMPACT Trial Accepted for Oral Presentation