Systemic hypertension is a very common risk factor for cardiovascular disease including stroke, coronary artery disease, atrial fibrillation and heart failure.  Effective treatment of hypertension often requires the use of three anti-hypertensive agents and in cases of refractory hypertension, 4 or 5 agents are used.  Side effects and poor patient adherence to treatment are important causes of drug discontinuation and poor blood pressure control in many cases. Therefore, a treatment able to tackle the main mechanisms leading to hypertension, that is effective for blood pressure control over the long time and is not associated with side effects, would be desirable in clinical practice.

Several studies in the past decade suggested that radiofrequency-based renal denervation can reduce blood pressure in patients with hypertension but results were in general inconclusive (1-4). A recent study by Azizi et al in the Lancet (5), RADIANCE-HTN SOLO (ClinicalTrials.gov, number NCT02649426), investigated the effects of a different technique i.e. endovascular ultrasound renal denervation, reduces ambulatory blood pressure in patients with hypertension in the absence of antihypertensive medications.

The advantage of RADIANCE-HTN SOLO over previous studies was that it was a multicentre, international, single-blind (patients and outcome assessors were blinded to randomisation), randomised, sham-controlled trial done at centres in the USA (n=21) and in Europe (n=18). Patients aged 18–75 years were eligible if they had systolic and diastolic hypertension and ambulatory blood pressure greater than or equal to 135/85 mm Hg and less than 170/105 mm Hg after having discontinued their antihypertensive medication (up to two agents) for 4 weeks. They also had suitable renal artery anatomy for implementation of the renal denervation technique. Importantly, patients were randomised (1:1) to undergo renal denervation or a sham procedure consisting of renal angiography only. Between March 28, 2016, and Dec 28, 2017, 803 patients were assessed for eligibility and 146 were randomised to undergo renal denervation (n=74) or the sham procedure (n=72). The primary study endpoint was the change in daytime ambulatory systolic blood pressure at 2 months in the “intention-to-treat” group. Patients stayed off antihypertensive medications throughout 2 months of follow-up. Major adverse events included all-cause mortality, renal failure, an embolic event with end-organ damage, renal artery or other major vascular complications requiring intervention, or admission to hospital for hypertensive crisis within 30 days and new renal artery stenosis within 6 months.

The main finding of the study was a reduction in daytime ambulatory systolic blood pressure, which was greater with renal denervation (−8·5 mm Hg, SD 9·3) than with the sham procedure (−2·2 mm Hg, SD 10·0; baseline-adjusted difference between groups: −6·3 mm Hg, 95% CI −9·4 to −3·1, p=0·0001). Of interest, no major adverse events were reported in either group.

These results open new avenues for research into the role of renal denervation for treatment of hypertension and renew interest in renal denervation as a procedure with potential application in clinical practice in the near future.

References

1. Krum, H, Schlaich, M, Whitbourn, R et al. Catheter-based renal sympathetic denervation for resistant hypertension: a multicentre safety and proof-of-principle cohort study. Lancet. 2009; 373: 1275–1281
2. Coppolino, G, Pisano, A, Rivoli, L, and Bolignano, D. Renal denervation for resistant hypertension. Cochrane Database Syst Rev. 2017; 2 (CD011499.)
3. Symplicity HTN-2 Investigators. Renal sympathetic denervation in patients with treatment-resistant hypertension (The Symplicity HTN-2 Trial): a randomised controlled trial. Lancet. 2010; 376: 1903–1909
4. Bhatt, DL, Kandzari, DE, O’Neill, WW et al. A controlled trial of renal denervation for resistant hypertension. N Engl J Med. 2014; 370: 1393–1401
5. Azizi M et al. Lancet 2018 Publication online – DOI: https://doi.org/10.1016/S0140-6736(18)31082-1