Renal denervation using ultrasound could prove to be an alternative to lifelong drug treatment for hypertension. Research published in the Lancet shows that the technique significantly reduced systolic blood pressure at two months in patients with hypertension that was resistant to drug treatment.1
The one hour operation uses ultrasound energy to disrupt the nerves between the kidneys and the brain that carry the signals controlling blood pressure.
Radiofrequency ablation of the renal nerves has been investigated previously, with mixed results. A 2017 Cochrane Collaboration meta-analysis found moderate quality evidence that renal denervation did not change office or ambulatory blood pressure when compared with antihypertensive treatment.2 However, that meta-analysis did not include renal denervation in patients with hypertension who were not using antihypertensive treatment.
The RADIANCE-HTN SOLO international multicentre trial included 146 patients who had ambulatory blood pressure ≥135/85 mm Hg and <170/105 mm Hg after a four week discontinuation of two or fewer antihypertensive drugs. Participants were randomly assigned to receive ultrasound renal denervation or a sham procedure consisting of renal angiography only. The patients avoided blood pressure medicines for two months, unless specified blood pressure levels were exceeded.
The patients who underwent renal denervation showed a reduction in daytime ambulatory systolic blood pressure of 8.5 mm Hg, compared with a reduction of 2.2 mm Hg in the sham group (adjusted difference between groups –6.3 mm Hg (95% confidence interval –9.4 to –3.1); P=0.001). This is similar to the benefit of one effective antihypertensive drug.
Over 66% of patients treated with renal denervation showed a 5 mm Hg or greater reduction in blood pressure, compared with 33% in the sham group. Patients who underwent renal denervation were more likely to achieve daytime ambulatory blood pressure control than patients in the sham group (22% v 3%; P=0.003). No major adverse events were reported in either group.
One limitation of the study is that follow-up was for only two months, as the researchers chose to minimise the time that patients avoided taking antihypertensive drugs. Longer term follow-up of the treatment effect is planned for as long as three years.
The UK principal investigator, Melvin Lobo, from Queen Mary University of London and Bart’s Health NHS Trust, said, “These results leave us clinicians in no doubt that this ultrasound based therapy works to improve blood pressure control—at least in the short term.
“Further larger trials will be needed to confirm the efficacy and safety of the technology, but we hope that they could lead to renal denervation therapy being offered as an alternative to lifelong medications for hypertension.”
The study was funded by ReCor Medical, which manufactures the renal denervation system used in the study.
- M AziziR SchmiederF Mahfoud. Endovascular ultrasound renal denervation to treat hypertension (RADIANCE-HTN SOLO: a multicentre, international, single-blind, randomised, sham controlled trial. Lancet2018;(May). 10.1016/S0140-6736(18)31082-1.
- G CoppolinoA PisanoL RivoliD Bolignano. Renal denervation for resistant hypertension. Cochrane Database Syst Rev2017;2:CD011499.28220472
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