Percutaneous transluminal radiofrequency sympathetic denervation of the renal artery for resistant hypertension - Consultation Document
Interventional procedure consultation document
Percutaneous transluminal radiofrequency sympathetic denervation of the renal artery for resistant hypertension
Cutting nerve supplies to the kidneys to reduce blood pressure
Hypertension (or chronic high blood pressure) raises the risk of having events such as heart attack, stroke or death. It is usually treated with lifestyle changes or medication to reduce the heart rate but sometimes these treatments are not enough to reduce a person’s blood pressure. Nerves located in the renal artery wall communicate information from the kidney to the brain to control blood pressure. In this procedure, a device is inserted through the groin to deliver heat energy to the renal nerves with the aim of reducing blood pressure.
The National Institute for Health and Clinical Excellence (NICE) is examining percutaneous transluminal radiofrequency sympathetic denervation of the renal artery and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about resistant hypertension.
This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:
- comments on the provisional recommendations
- the identification of factual inaccuracies
- additional relevant evidence, with bibliographic references where possible.
Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.
The process that NICE will follow after the consultation period ends is as follows.
- The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
- The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.
For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).
Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.
In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:
Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination and promote equality and foster good relations between people with a characteristic protected by the equalities legislation and others?
Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.
Closing date for comments: 24 June
Target date for publication of guidance: October 2011
1 Provisional recommendations
1.1 Current evidence on limited numbers of patients shows that percutaneous transluminal radiofrequency sympathetic denervation of the renal artery for resistant hypertension is efficacious in the short and medium term. There is a potential for serious complications, but based on the limited number of patients reported, these are uncommon. This procedure should only be used with special arrangements for clinical governance, consent and audit or research.
1.2 Clinicians wishing to undertake percutaneous transluminal radiofrequency sympathetic denervation of the renal artery for resistant hypertensionshould take the following actions.
- Inform the clinical governance leads in their Trusts.
- Ensure that patients understand the uncertainty about the procedure’s safety and efficacy and provide them with clear written information. In addition, the use of NICE’s information for patients (‘Understanding NICE guidance’) is recommended (available from www.nice.org.uk/IPGXXXpublicinfo). [[details to be completed at publication]]
- Audit and review clinical outcomes of all patients having percutaneous transluminal radiofrequency sympathetic denervation of the renal artery for resistant hypertension (see section 3.1).
1.3 Patient selection should be carried out by a multidisciplinary team including a physician with expertise in hypertension and a specialist in endovascular interventions, giving due consideration to the number of antihypertensive drugs that have failed to control the patient’s blood pressure and the anatomical suitability of their renal arteries.
1.4 NICE encourages further research and data collection on this procedure. Patient selection criteria should be described clearly and reported outcome measures should include adverse events and the long-term effect of the procedure on blood pressure. NICE may review the procedure on publication of further evidence.
2 The procedure
2.1 Indications and current treatments
2.1.1 Hypertension is a major risk factor for cardiovascular disease (including stroke and myocardial infarction) and for chronic renal disease. First-line treatment usually involves lifestyle changes, such as diet modification and exercise. Combinations of antihypertensive medications may be introduced for the management of resistant hypertension.
2.2 Outline of the procedure
2.2.1 Percutaneous transluminal radiofrequency sympathetic denervation of the renal artery for resistant hypertension aims to disrupt both local and central neurogenic reflexes that are involved in blood pressure control.
2.2.2 The procedure is usually carried out with the patient under local anaesthesia with conscious sedation, and anticoagulation medication is given. A radiofrequency catheter is introduced via the femoral artery and advanced into each renal artery under fluoroscopic control. The catheter is connected to a generator which delivers low-power radiofrequency energy in 2-minute applications to each renal artery at 4–6 points along its length, in a spiral pattern.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview, available at www.nice.org.uk/guidance/IP/923/overview
2.3.1 A randomised controlled trial (RCT) of 100 patients treated by renal artery denervation (n = 49) or unchanged medical therapy (n = 51) reported an average reduction from baseline in blood pressure measurements of 32/12 mmHg and 1/0 mmHg respectively at 6-month follow-up (p < 0.001 for both systolic blood pressure [SBP] and diastolic blood pressure [DBP] in the treatment group compared with p = 0.83 for SBP and p = 0.77 for DBP in the control group).
2.3.2 The RCT of 100 patients comparing renal artery denervation versus unchanged medical therapy reported an average reduction in blood pressure (24-hour monitoring) of 11/7 mmHg and 3/1 mmHg respectively at 6-month follow-up (p = 0.006 for SBP and p = 0.014 for DBP versus p = 0.51 for SBP and p = 0.75 for DBP).
2.3.3 A case series of 153 patients reported a mean reduction in blood pressure of 25/11 mmHg at 6 months (n = 86), 23/11 mmHg at 12 months (n = 64), 26/14 mmHg at 18 months (n = 36), and 32/14 mmHg at 24 months (n = 18) (within-patient changes in both SBP and DBP from baseline were p < 0.0001 at all time points except at 24 months [p = 0.002]).
2.3.4 The Specialist Advisers listed key additional efficacy outcomes as reduction in cardiovascular morbidity and mortality, improvement in the parameters of renal function and regression in left ventricular mass.
2.4.1 Renal artery dissection was reported in 1 patient in the case series of 153 patients: this was stented with no adverse sequelae.
2.4.2 Each of the following serious adverse events (requiring hospitalisation) was reported in 1 patient treated by renal artery denervation in the RCT of 100 patients: nausea and oedema, hypertensive crisis after clonidine was abruptly stopped, and a hypotensive episode requiring a reduction in antihypertensive medication (timing of events not stated).
2.4.3 Each of the following minor periprocedural events was reported in 1 patient treated by renal artery denervation in the RCT of 100 patients: femoral artery pseudoaneurysm (treated by manual compression), paraesthesia (requiring extended hospital stay), back pain (resolved after 1 month) and transient intraprocedural bradycardia (treated with atropine).
2.4.4 The case series of 153 patients reported that 1 patient had bilateral flank pain which required analgesia (ibuprofen) for several months before it resolved.
2.4.5 The Specialist Advisers listed anecdotal adverse events as transient pain from the delivery of radiofrequency energy and renal artery perforation. They considered theoretical adverse events to include late stenosis or promotion of atheroma in the renal artery in the long-term, sodium depletion and hypotension.
3 Further information
3.1 This guidance requires that clinicians undertaking the procedure make special arrangements for audit. NICE has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.
3.2 For related NICE guidance see www.nice.org.uk
Chairman, Interventional Procedures Advisory Committee
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It is the responsibility of consultees to accurately cite academic work in order that they can be validated.
This page was last updated: 28 June 2011