SPYRAL HTN-OFF MED Study
Research type
Research Study
Full title
Global Clinical Study of Renal Denervation with the Symplicity Spyral™ multi-electrode renal denervation system in Patients with Uncontrolled Hypertension in the Absence of Antihypertensive Medications (SPYRAL HTN-OFF MED Study)
IRAS ID
180563
Contact name
Marianne Wanten
Contact email
Sponsor organisation
Medtronic Inc - Bakken Research Centre
Clinicaltrials.gov Identifier
Duration of Study in the UK
4 years, 4 months, 1 days
Research summary
Research Summary
The purpose of this study is to provide additional information about a medical device intended to help treat high blood pressure in patients whose blood pressure is not controlled, in the absence of antihypertensive medication. A recent study (SYMPLICITY HTN-3) conducted by Medtronic showed that the previous Symplicity™ renal denervation system, which included a similar radiofrequency generator and a single (one) electrode Symplicity catheter was safe, but did not lower blood pressure as expected. The SYMPLICITY HTN-3 study was done in a different hypertensive patient population that required all patients to be on at least three antihypertensive medications at the highest dose the patients could tolerate. A similar decrease in blood pressure was seen after 6 months in the patients who received renal denervation and in the patients treated only with medications. Renal denervation in this study was found to be safe. The learnings from that study are being tested in the current study and include a more extensive treatment with a different catheter. The device in this study uses up to 4 electrodes at a time to deliver the same kind of energy in a specific pattern to disrupt the nerves. This study will be “Randomized” meaning that patients who meet the study criteria will be randomly assigned to one of two groups. The study is “Controlled” meaning half of the patients will be treated with the device (the “Denervation Group”) and the other half will NOT be treated with the device (the “Control Group”). Each patient has a 50% chance of being assigned to the Denervation Group. This study is also “Blinded” meaning that patients will not be told which group they are assigned to, and certain procedures will be followed to prevent patients from knowing which group they are in until the specified time point.
Summary of Results
In the Pivotal cohort, there were 1519 subjects enrolled to randomize 331 patients to renal denervation (N=166) or sham control (N=165). The primary and secondary effectiveness endpoints were met, with posterior probability of superiority >0.999 separately for each. The average treatment differences were -3.9 mmHg (Bayesian 95% credible interval: -6.2 to -1.6) in 24-hour systolic blood pressure and -6.5 mmHg (-9.6 to -3.5) in office systolic blood pressure between groups. Treatment differences in 24-hour and office diastolic pressure at 3 months were -3.1 mmHg (95% confidence interval: -4.6 to -1.7) and -4.4 mmHg (-6.2 to -2.6), respectively.
In the Full cohort, there were 1629 subjects enrolled to randomize 366 patients to renal denervation (N=182) or sham control (N=184). Office SBP and 24-hour ASBP were similar in both groups to 36 months; however, the anti-hypertensive medication burden was higher in the Control group using prescribed medications and drug testing out to 36 months.
In both the Pivotal and Full cohorts, similar results were obtained in a prespecified Frequentist analysis of these data. Reductions in blood pressure after renal denervation were consistent throughout 24 hours, with significant differences in night-time and daytime blood pressure from baseline to 3 months for renal denervation patients. Treatment differences for 24-hour systolic blood pressure in key baseline characteristic subgroups demonstrated no significant interactions between subgroups.
REC name
London - Dulwich Research Ethics Committee
REC reference
15/LO/1641
Date of REC Opinion
30 Nov 2015
REC opinion
Further Information Favourable Opinion