- Renal denervation is a catheter procedure that uses radio-frequency or ultrasound energy to disrupt nerves around the kidney arteries. The first large sham-controlled trial, SYMPLICITY HTN-3, was negative: office systolic pressure fell 2.4 mm Hg more than with sham (95% CI −6.9 to 2.1; p=0.26) in 535 people. Medtronic funded it (Bhatt et al., NEJM 2014).
- Later sham-controlled trials with redesigned protocols found modest benefits. The ambulatory systolic drop beyond sham was 3.9 mm Hg in SPYRAL HTN-OFF MED (Medtronic funded) and about 6 mm Hg in the two RADIANCE trials off medicines (ReCor funded for SOLO; RADIANCE II had ReCor employees as authors) (SPYRAL; RADIANCE-HTN SOLO; RADIANCE II).
- A meta-analysis of 10 sham-controlled trials (2,478 people) found 24-hour systolic pressure 4.4 mm Hg lower than sham (95% CI 2.7 to 6.1) and no clear excess of vascular complications. The confidence intervals for rarer harms, such as renal artery stenosis, are very wide (OR 1.50, 95% CI 0.06 to 37), so low-frequency harm cannot be excluded (Vukadinović et al., Circulation 2024).
- The US FDA approved two systems in November 2023: ReCor's Paradise on 7 November and Medtronic's Symplicity Spyral on 17 November, according to a 2026 open-access review (Skalidis et al. 2026). The same review reports a Medicare national coverage determination dated 28 October 2025 that requires continued evidence collection. We could not open the CMS or NICE pages themselves.
- Guidelines are cautious. The 2025 US guideline gives renal denervation a Class 2b recommendation (weak), and the ESC 2024 guideline IIb, as summarised by a 2026 review (Stephan et al. 2026). Long-term data beyond three years are thin, and most follow-up is unblinded and uncontrolled.
- Money trail: Every sham-controlled trial we opened was funded by, or tested the product of, a device maker. We found no publicly funded sham-controlled trial among the sources we opened. The cleanest sources are an NIH-supported meta-analysis and an unfunded academic review, but both pool or summarise industry-run trials. See the scorecard.
- Evidence grade: Moderate that it lowers blood pressure a little more than sham in the short term. Weak for durability past three years and for any effect on strokes, heart attacks or deaths (not yet measured in sham-controlled trials we opened). Insufficient for rare late harms.
Independent evidence review · Medical procedure
Renal denervation probably lowers blood pressure by a modest amount, roughly 4 to 6 mm Hg more than a sham procedure in the best trials, after a first major trial found no difference. Every sham-controlled trial we opened was paid for by a device maker, so the evidence base is consistent but not independently replicated. Short-term safety looks good, but the studies are too small to rule out rare harms, and no sham-controlled trial we opened has shown fewer strokes or heart attacks. Our confidence: moderate that a small blood-pressure effect exists; low for long-term benefit and rare harms.
Table of contents
- Evidence summary
- What renal denervation is, and its approval status
- How it works
- What works and what does not
- Benefits by claim
- Risks and all side effects
- Medicines, tests and interactions
- Who may not be suitable
- The procedure and how the trials were run
- Follow the money: who makes it and who funded the evidence
- Related research
- Frequently asked questions
- Sources and funding notes
Evidence summary
| Claim | Evidence | Source | Funding / conflict | Strength |
|---|---|---|---|---|
| Renal denervation beats sham in severe resistant hypertension (original radio-frequency device) | 535 people, 2:1 to procedure or sham. Office systolic change 2.39 mm Hg greater with procedure (95% CI −6.89 to 2.12; p=0.26). 24-hour ambulatory difference 1.96 mm Hg (95% CI −4.97 to 1.06). Negative. | Bhatt 2014 | Funded by Medtronic. Three authors listed with Medtronic CardioVascular, Santa Rosa, US. | Moderate (against the claim) |
| Radio-frequency renal denervation lowers pressure off medicines | SPYRAL HTN-OFF MED Pivotal: 331 people. 24-hour systolic difference −3.9 mm Hg (Bayesian 95% credible interval −6.2 to −1.6); office −6.5 mm Hg (−9.6 to −3.5). No major device or procedure safety events to 3 months. | Böhm 2020 | Funding text: Medtronic. The record also lists grants from the German DFG, FDA, NIHR and NHLBI (recipients not stated). | Moderate |
| The radio-frequency effect lasts to 36 months | SPYRAL HTN-ON MED (80 randomised). At 36 months the 24-hour systolic fall was 18.7 vs 8.6 mm Hg (adjusted difference −10.0; 95% CI −16.6 to −3.3). Only 30 and 32 people were measured at 36 months. | Mahfoud 2022 | Medtronic funded. Three authors listed with Medtronic, Santa Rosa. | Weak |
| Ultrasound renal denervation lowers pressure off medicines | RADIANCE-HTN SOLO: 146 people, daytime systolic difference −6.3 mm Hg (95% CI −9.4 to −3.1) at 2 months. RADIANCE II: 224 people, −6.3 mm Hg (95% CI −9.3 to −3.2). | Azizi 2018; Azizi 2023 | SOLO funding text: ReCor Medical. RADIANCE II record shows a Barts Charity grant; two authors are ReCor Medical employees and another works for a ReCor contractor (NAMSA), so ReCor involvement is documented even though the sponsor line was not seen. | Moderate |
| Ultrasound renal denervation helps resistant hypertension on a triple-pill regimen | RADIANCE-HTN TRIO: 136 randomised. Median daytime systolic difference −4.5 mm Hg (95% CI −8.5 to −0.3) at 2 months. | Azizi 2021 | Funding text: ReCor Medical. | Moderate |
| Pooled sham-controlled trials show a real, modest effect | 10 trials, 2,478 people. 24-hour systolic −4.4 mm Hg (95% CI 2.7 to 6.1); office systolic −6.6 mm Hg (95% CI 3.6 to 9.7). Significant heterogeneity between trials. | Vukadinović 2024 | Record lists NHLBI grant R01 HL161069; no separate funding statement or author conflicts seen. Pools mainly device-maker-funded trials. | Moderate |
| Renal artery stenosis or dissection after radio-frequency denervation | 50 trials, 5,769 people, 10,249 patient-years: 26 (0.45%) had stenosis or dissection; 24 (0.41%) needed a stent. Pooled stent rate 0.20% a year (95% CI 0.12% to 0.29%). 79% of events within a year. | Townsend 2020 | Funding not stated in the record we opened (full text paywalled). Only the first author's affiliation (University of Pennsylvania) is shown; it covers Medtronic's system only. | Risk (low frequency) |
| No excess of vascular complications versus sham | Vascular complications OR 1.69 (95% CI 0.57 to 5.0); renal artery stenosis >70% OR 1.50 (0.06 to 37); death OR 1.76 (0.34 to 9.2). These intervals are too wide to prove safety. | Vukadinović 2024 | As above | Insufficient |
| Renal denervation reduces strokes, heart attacks or deaths | Not measured as an outcome in the sham-controlled trials we opened. Trial endpoints were blood pressure. | Skalidis 2026 | Review stated "no external funding" | Insufficient |
Independent evidence and credibility scorecard
Independence tiers: 1 = regulator or government body; 2 = academic or review team with no declared commercial funding for the work; 3 = independent authors analysing mostly manufacturer-run trials, professional societies, or minor declared industry ties; 4 = manufacturer-funded or manufacturer-authored. Credibility runs from A (highest) to D. Sources cluster in Europe and the US.
| Source | Who funds it | Country | Independence tier (1–4) | Credibility (A–D) | Why it would tell the truth / residual bias |
|---|---|---|---|---|---|
| FDA Circulatory System Devices Panel notice (Federal Register, 2023) | US federal government | US | 1 | A | Legal notice of a public advisory meeting on 22–23 August 2023. No product to sell and publicly accountable. It records the meeting only, not the evidence or the decision. |
| Skalidis et al. 2026 review (J Cardiovasc Dev Dis) | "No external funding"; several authors employed by hospital group Ramsay Santé | Not verified (authors at Ramsay Santé) | 2 | B | Open-access and declares no commercial ties. A narrative review, so it relies on other people's numbers. We used it for approval dates and guideline classes that we could not open at source. |
| Stephan et al. 2026 guidelines comparison | No funding or conflict statement seen | Not verified | 2 | C | Open-access comparison of ESH, ESC and ACC/AHA classes. No disclosure statement in the content we read, so its independence is unconfirmed. |
| Vukadinović et al., Circulation 2024 meta-analysis | NHLBI (NIH) grant R01 HL161069 listed; no author conflicts seen | US (NIH grant; author country not verified) | 3 | B | Independent authors, pre-defined sham-only design, reports wide intervals honestly. Almost all pooled trials were device-maker-funded, and heterogeneity was significant. |
| Townsend et al., EuroIntervention 2020 (renal artery damage) | Not stated in record | Not verified (journal: Europe) | 3 | C | The only large pooled count of renal artery injury we found. Funding and author conflicts could not be checked; it pools trials that were mostly device-maker-funded. |
| ESC / EAPCI clinical consensus statement (Barbato et al. 2023) | Not stated in record. Professional societies fund themselves from membership, congresses and sponsors (not verified here) | Europe (ESC is based in France; not verified here) | 3 | B | Expert consensus with reputational stake in cautious advice. Several named authors (Azizi, Böhm, Schmieder, Lauder) are also trial investigators; their disclosures were not checked. |
| 2023 ESH hypertension guidelines (Mancia et al.) | Not stated in record. Opened as a record only, with recommendation class taken from the Stephan review | Europe | 3 | B | Guideline committees usually publish conflict declarations, which we did not open. Class II/B is second-hand. |
| SYMPLICITY HTN-3 (Bhatt et al., NEJM 2014) | Medtronic | US (Medtronic Santa Rosa authors) | 4 | B | Sham-controlled and blinded, and the sponsor published a negative result, so honesty paid. Still sponsor-funded with sponsor staff as authors. |
| SPYRAL HTN-OFF MED Pivotal (Böhm et al., Lancet 2020) | Medtronic (funding text); record also lists DFG, FDA, NIHR, NHLBI grants | International (44 sites in 9 countries) | 4 | B | Sham-controlled, intention-to-treat. Used a Bayesian design with an informative prior from the pilot trial, which can favour a positive result. |
| SPYRAL HTN-ON MED long-term (Mahfoud et al., Lancet 2022) | Medtronic; three authors with Medtronic affiliations | International | 4 | C | Only 80 people were randomised and about 60 measured at 36 months. Long-term sham comparison is fragile. |
| RADIANCE-HTN SOLO (Azizi et al., Lancet 2018) | ReCor Medical | International (US and Europe) | 4 | B | Blinded, sham-controlled, intention-to-treat. Two-month endpoint only; sponsor made the Paradise device. |
| RADIANCE-HTN TRIO (Azizi et al., Lancet 2021) | ReCor Medical | International | 4 | B | Standardised single-pill regimen reduces medicine-change noise. Effect was smaller and the lower CI bound close to zero. |
| RADIANCE II (Azizi et al., JAMA 2023) | Barts Charity grant listed; two authors are ReCor employees and one works for ReCor contractor NAMSA (conflict declaration); tested the ReCor Paradise device | International (US and Europe) | 4 | B | Provisional tier 4 because the device tested is a manufacturer's. Largest single sham-controlled ultrasound trial. |
| RADIANCE-HTN TRIO 36-month follow-up (Bloch et al. 2024) | Not stated in record; two co-authors listed with Recor Medical | International | 4 | C | Unblinded follow-up; 71% of the procedure group were seen at 36 months, and there is no control group after the early phase. |
| Pooled 36-month SPYRAL results (Kandzari et al. 2026) | Not stated in record; one author listed with Medtronic | International | 4 | C | Large (2,137 people) but uncontrolled; combines registry and trial data from the maker's programme. |
| UK Delphi consensus (Haworth et al., Heart 2026) | Medtronic Europe listed as the grant agency | UK | 4 | C | 125 UK clinicians rated statements on when to use the procedure. Maker-funded, so we treat it as context, not evidence. |
Convergence and clustering. Two rival makers (Medtronic with radio-frequency, ReCor with ultrasound) each ran sham-controlled trials and each found a modest benefit. That is a useful sign because each has a commercial reason to want the other's device to fail, but both also share the interest of building a market for the procedure. Our tier-1 and tier-2 sources are few. The two critical datapoints, the HTN-3 negative result and the renal artery injury counts, came from a sponsor that published against its own interest and from a pooled count whose funding we could not see.
What renal denervation is, and its approval status
Renal denervation is a catheter procedure. A thin tube is passed through an artery, usually from the groin, into the arteries that supply the kidneys. Energy is delivered to the artery wall to disrupt the nerves running alongside. The two systems with US approval use radio-frequency energy (Medtronic Symplicity Spyral) or ultrasound (ReCor Paradise). A third approach, injecting alcohol around the artery, remains investigational (Skalidis 2026).
- United States, FDA: an FDA advisory panel reviewed both devices on 22 and 23 August 2023 (Federal Register notice; Chitturi et al. 2024). A 2026 review reports approvals on 7 November 2023 for Paradise and 17 November 2023 for Symplicity Spyral (Skalidis 2026). We could not open FDA's own approval pages.
- United States, Medicare: the same review reports a national coverage determination (NCD 20.40) dated 28 October 2025. Coverage requires documented uncontrolled hypertension despite stable medicines, confirmation by ambulatory or home readings, an adherence check, exclusion of secondary causes, a trained operator in a multidisciplinary programme, and continued participation in evidence collection (coverage with evidence development). It applies to Medicare only (Skalidis 2026). We could not open the CMS decision itself, so treat the date and criteria as second-hand.
- United Kingdom, NICE: NICE interventional procedures guidance IPG418 covers this procedure. NICE's site blocked our request, so we do not report its content. A 2026 UK expert Delphi paper, funded by Medtronic Europe, says its recommendations could support NICE reviews (Haworth 2026).
- Europe: an ESC/EAPCI consensus statement (2023) calls it an adjunct option for uncontrolled resistant hypertension confirmed by ambulatory measurement, and for people who cannot tolerate medicines long term, with shared decision-making and specialist teams (Barbato 2023).
How it works
The kidneys and the nerves that supply them help set blood pressure. The idea is that disrupting these nerves reduces overactive sympathetic signalling that raises pressure. Our sources describe this as the rationale (Stephan 2026, durability review). What is shown in humans is a blood-pressure fall versus sham. Direct proof that nerve activity falls, and stays down, is not something we opened. Animal studies show partial nerve regrowth after denervation, and human data on regrowth are absent (Skalidis 2026).
What works and what does not
| Claim | Verdict | Why |
|---|---|---|
| Small fall in ambulatory systolic pressure beyond sham | Works (modestly) | Consistent in several blinded trials and a pooled analysis: 4.4 mm Hg for 24-hour systolic (Vukadinović 2024). |
| Replaces medicines | Insufficient | Pooled 36-month data show average medicine number falling only from 3.8 to 3.5 (Kandzari 2026). |
| Works in the original severe resistant-hypertension setting with office readings | Mixed | HTN-3 was negative; TRIO (resistant, triple pill) was positive but smaller (−4.5 mm Hg). |
| Effect lasts three years | Mixed | Uncontrolled data show sustained falls; sham-controlled evidence at 36 months comes from a few dozen people. |
| Reduces strokes, heart attacks or deaths | Insufficient | Not measured as outcomes in the sham-controlled trials we opened. |
| Safe long term | Insufficient | Short-term events are rare, but meta-analytic intervals for rare harms are wide. |
Benefits by claim
Does it lower blood pressure?
Probably yes, by a small amount. SYMPLICITY HTN-3 randomised 535 people with severe resistant hypertension, all on at least three medicines including a diuretic. Both groups improved at 6 months, but the procedure did not beat sham on office systolic pressure (difference −2.39 mm Hg; 95% CI −6.89 to 2.12) (Bhatt 2014). Later trials changed the design. SPYRAL HTN-OFF MED enrolled 331 people with office systolic 150 to under 180 mm Hg off medicines and used 24-hour ambulatory pressure as the main endpoint: −3.9 mm Hg (Bayesian 95% credible interval −6.2 to −1.6) (Böhm 2020). In plain English, a drop of 4 mm Hg is real but small. It is the size of a low-dose single medicine, and an individual may respond more or less.
Ultrasound versus radio-frequency
The ReCor ultrasound trials reported larger differences than SPYRAL, about 6 mm Hg versus sham for daytime ambulatory systolic. SOLO (146 people, off medicines): −6.3 mm Hg (95% CI −9.4 to −3.1) at 2 months (Azizi 2018). RADIANCE II (224 people): −6.3 mm Hg (95% CI −9.3 to −3.2) (Azizi 2023). These trials used different endpoints, so we cannot say one device is better. No head-to-head trial was in the sources we opened.
People whose pressure stays high on several medicines
RADIANCE-HTN TRIO first switched 989 enrolled people to a standard triple pill. Of those, 136 whose pressure stayed high were randomised. The median daytime systolic difference was −4.5 mm Hg (95% CI −8.5 to −0.3), with similar adherence (82%) in both groups (Azizi 2021). The lower bound is close to zero, so the true effect could be tiny. See our guide to resistant hypertension for how to confirm the diagnosis first.
How long does the effect last?
In the SPYRAL ON MED pilot, 24-hour systolic fell 18.7 mm Hg at 36 months with the procedure versus 8.6 with sham (adjusted difference −10.0; 95% CI −16.6 to −3.3), but only 30 and 32 people were measured, medicine counts changed (2.13 vs 2.55) and adherence was 77% versus 93% (Mahfoud 2022). In TRIO, 71% of the procedure group were followed to 36 months, with office pressure down 8.0 mm Hg from baseline on 3.7 medicines (Bloch 2024). A pooled SPYRAL analysis of 2,137 people reported an office systolic fall of 18.1 mm Hg and an ambulatory fall of 13.3 mm Hg at 36 months, with 88% meeting a clinical benefit definition (Kandzari 2026). These are uncontrolled, so regression to the mean, extra medicines and the placebo effect are not separated out.
Strokes, heart attacks and kidney protection
We found no sham-controlled trial of the opened set that measured these outcomes. A pooled analysis reported estimated kidney filtration changes were similar to sham (eGFR change −0.75 versus −0.62 mL/min/1.73 m², as summarised by Skalidis 2026). The ESC consensus calls for more research on clinical outcomes (Barbato 2023).
Risks and all side effects
- Vascular and access-site problems: a review reports overall vascular complications of about 0.5%, with access-site complications under 1% (Skalidis 2026). In the pooled sham-controlled analysis, vascular complications did not differ from sham (OR 1.69; 95% CI 0.57 to 5.0) (Vukadinović 2024).
- Pain: the same review reports procedural pain beyond two days in about 12% of people in earlier meta-analyses (Skalidis 2026).
- Kidney function: change in eGFR did not differ from sham (interaction p=0.84) (Vukadinović 2024).
- Hypertensive crisis and death: no clear difference from sham (OR 0.65, 95% CI 0.30 to 1.38; OR 1.76, 95% CI 0.34 to 9.20), but wide intervals (Vukadinović 2024).
- Trial safety summaries: HTN-3 safety did not differ from sham; SPYRAL OFF MED reported no major device or procedure events to 3 months; RADIANCE II reported no major adverse events (Bhatt 2014; Böhm 2020; Azizi 2023).
- Late harms: sham-controlled follow-up beyond 6 months is short or small. Partial nerve regrowth in animals is a theoretical concern, and human data are absent (Skalidis 2026).
Medicines, tests and interactions
We found no drug-interaction data in the sources we opened, and we do not report any. What the trials show is how the studies handled medicines. SOLO and RADIANCE II used a washout of up to two medicines, and RADIANCE II withheld medicines until the 2-month visit unless pressure rose with symptoms (Azizi 2023). TRIO used a fixed triple pill (Azizi 2021). The sham in SOLO was renal angiography only, so both groups had an arterial procedure (Azizi 2018). Contrast-dye effects on the kidney were not described in the abstracts we read, so we could not verify them. Pressure should be tracked with out-of-office readings; see home blood pressure monitoring and blood pressure medicines.
Who may not be suitable
Suitability is decided by a specialist team, not by us. What the sources show:
- Medicare coverage criteria require documented uncontrolled hypertension despite stable, maximally tolerated medicines, confirmation by ambulatory or home readings, an adherence check, exclusion of secondary hypertension and no contraindication in the device labelling (Skalidis 2026). For secondary causes, see secondary hypertension.
- Trial populations were selected. RADIANCE II excluded people with eGFR below 40 mL/min/1.73 m² and required suitable renal artery anatomy in SOLO (Azizi 2023; Azizi 2018). Results may not apply outside those groups.
- Pregnancy, breastfeeding, children and advanced kidney disease: not covered by the sources we opened, so we could not verify them. For kidney disease and the heart, see chronic kidney disease and the heart.
The procedure and how the trials were run
There is no dose. Two energy types are approved in the US: radio-frequency (Symplicity Spyral, Medtronic) and ultrasound (Paradise, ReCor) (Skalidis 2026). The ESC consensus says operators need renal intervention skills and device-specific training, and centres need resources to handle complications (Barbato 2023). Trial design changed between HTN-3 and later studies: HTN-3 used office pressure at 6 months on a stable regimen of at least three medicines; later trials used ambulatory pressure at 2 to 3 months, often off medicines or on a fixed pill. Short follow-up is a strength for control and a weakness for durability.
Follow the money: who makes it and who funded the evidence
Who makes and sells it
- Medtronic plc: maker of Symplicity Spyral. Its SEC filing page lists a principal executive office in Galway, Ireland (SEC EDGAR). Trial authors list Medtronic in Santa Rosa, California (Bhatt 2014). How Medtronic acquired the renal denervation technology could not be verified from sources we opened.
- ReCor Medical: maker of the Paradise ultrasound system, and funder of RADIANCE-HTN SOLO and TRIO (SOLO; TRIO). Its parent company and country could not be verified from sources we opened.
Who funded the trials and consensus papers
- SYMPLICITY HTN-3, SPYRAL OFF MED and ON MED: funding text names Medtronic in each case (HTN-3; OFF MED; ON MED). OFF MED also lists DFG, FDA, NIHR and NHLBI grants in its record, but not who held them.
- RADIANCE-HTN SOLO and TRIO: funding text names ReCor Medical; SOLO also lists an NIHR grant (SOLO; TRIO). RADIANCE II lists a Barts Charity grant; its authors include two ReCor employees and a ReCor contractor employee, but the sponsor line was not seen (RADIANCE II).
- UK Delphi consensus: Medtronic Europe is the listed grant agency (Haworth 2026).
- Meta-analysis: lists NHLBI grant R01 HL161069, with no separate funding statement (Vukadinović 2024).
- Guidelines and consensus statements (ESH, ESC/EAPCI): funding and author disclosures were not in the records we opened.
Research funding at a glance
16 sources graded. The counts below are the independence tiers assigned in the scorecard above. They count sources, not funding amounts or evidence quality.
Public funding alone does not prove independence, and commercial funding alone does not prove a claim false. Named funders, countries and relationships are in the scorecard and source notes.
Documented integrity events
We found no regulatory ban, warning letter or recall for these devices in the sources we opened. The main documented event in the evidence record is scientific: the first large blinded trial, funded by a maker, did not confirm the earlier unblinded promise (Bhatt 2014). The following trials, also maker-funded, changed design and reported modest benefit. That is not evidence of wrongdoing; it is a reason to want an independent, publicly funded replication.
Related research
For wider, evidence-graded context, see these Pure City Research guides:
- Resistant Hypertension: Confirming the Diagnosis, Treatment and Funding
- Hypertension: Accurate Measurement, Treatment, Safety and Evidence Funding
- Secondary Hypertension: Causes, Assessment, Treatment and Funding
- Renal Artery Stenosis: Blood Pressure, Kidney Function and Procedure Decisions
- Blood Pressure Medicines: Types, Monitoring, Side Effects and Safety
- Home Blood Pressure Monitoring: Technique, Readings, Devices and Safety
- High Blood Pressure: Prevention and Management Evidence
- Chronic Kidney Disease and the Heart: Cardiorenal Risks, Tests and Medicine Safety
- Hypertensive Emergency: Severe Readings, Warning Signs and Urgent Assessment
Frequently asked questions
Does renal denervation work?
Modestly, in the short term. The pooled sham-controlled result is 4.4 mm Hg lower 24-hour systolic pressure than sham (95% CI 2.7 to 6.1) (Vukadinović 2024). The first large trial found no difference (Bhatt 2014).
Why was SYMPLICITY HTN-3 negative when later trials were positive?
We could not verify the reasons from the sources we opened. We can say the later trials changed the design: they measured 24-hour or daytime ambulatory pressure, often off medicines or on a fixed pill (Böhm 2020; Azizi 2021), while HTN-3 used office readings at 6 months.
Is renal denervation approved?
In the US, a 2026 review reports FDA approval of two systems in November 2023 (Skalidis 2026). We could not open FDA's own pages. For NICE, we could not open the guidance, so we do not state its position.
Will Medicare cover it?
The same review reports a national coverage determination dated 28 October 2025 with criteria and an evidence-collection requirement, applying to Medicare only (Skalidis 2026). We could not open the CMS decision to confirm it.
What do the guidelines say?
A 2026 comparison reports Class 2b for the 2025 ACC/AHA guideline, IIb for ESC 2024 and Class II/B for ESH 2023, with specialist-centre assessment recommended in all (Stephan 2026). These are second-hand summaries.
Is it safe?
Short-term safety looks good: no major events in several sham-controlled trials and no excess of vascular complications in the pooled analysis, though intervals are wide (Vukadinović 2024). Renal artery stenosis or dissection occurred in about 0.45% across 50 trials (Townsend 2020).
How long does the effect last?
Uncontrolled follow-up reports sustained falls to 36 months (Kandzari 2026). Sham-controlled data at 36 months are limited to a few dozen people (Mahfoud 2022).
Who paid for the trials?
The sham-controlled trials we opened were paid for by Medtronic or ReCor Medical, or tested a maker's device (see the scorecard). Funding does not make them wrong, but it means the evidence has not been independently replicated.
Sources and funding notes
What we could not verify: NICE IPG418 (the NICE site blocked our request, so we do not report its content). The CMS decision itself (the date and criteria come from a 2026 review). FDA's own approval pages and the panel votes. ReCor Medical's ownership and country. How Medtronic acquired the technology. Author conflicts for the meta-analysis, the renal artery review and the ESC/EAPCI statement. Funding for the ESH 2023 guideline, whose recommendation class we took from a review. The RADIANCE II sponsor. Whether any publicly funded sham-controlled trial exists beyond the sources we opened. Direct evidence that nerve activity falls after the procedure. The Europe PMC records were used for abstracts and grant fields, so full-text conflict statements were mostly not read.
- Bhatt DL et al. A controlled trial of renal denervation for resistant hypertension (SYMPLICITY HTN-3). N Engl J Med 2014 — sham-controlled trial; Medtronic.
- Böhm M et al. SPYRAL HTN-OFF MED Pivotal. Lancet 2020 — sham-controlled trial; Medtronic (plus listed DFG, FDA, NIHR, NHLBI grants).
- Mahfoud F et al. SPYRAL HTN-ON MED long-term. Lancet 2022 — sham-controlled trial, 36 months; Medtronic.
- Azizi M et al. RADIANCE-HTN SOLO. Lancet 2018 — sham-controlled trial; ReCor Medical (NIHR grant listed).
- Azizi M et al. RADIANCE-HTN TRIO. Lancet 2021 — sham-controlled trial; ReCor Medical.
- Azizi M et al. RADIANCE II. JAMA 2023 — sham-controlled trial; Barts Charity grant listed; ReCor employees among authors.
- Bloch MJ et al. 36-month durability, RADIANCE-HTN TRIO. Hypertens Res 2024 — follow-up; funder not stated, two Recor co-authors.
- Kandzari DE et al. Pooled 36-month SPYRAL results. EuroIntervention 2026 — uncontrolled pooled data; funder not stated, one Medtronic author.
- Vukadinović D et al. Effects of catheter-based renal denervation in hypertension: systematic review and meta-analysis. Circulation 2024 — meta-analysis; NHLBI grant R01 HL161069 listed.
- Townsend RR et al. Renal artery damage after radiofrequency renal denervation: review and meta-analysis. EuroIntervention 2020 — meta-analysis; funder not stated.
- Barbato E et al. Renal denervation in the management of hypertension in adults. Eur Heart J 2023 — ESC/EAPCI consensus; funder not stated.
- Mancia G et al. 2023 ESH Guidelines for the management of arterial hypertension. J Hypertens 2023 — guideline record only; funder not stated.
- Skalidis I et al. Catheter-based renal denervation in uncontrolled and resistant hypertension. J Cardiovasc Dev Dis 2026 — review; "no external funding".
- Stephan D et al. Renal denervation for hypertension management: convergence and divergence across international guidelines. 2026 — review; no funding statement seen.
- Stephan D et al. Renal denervation in 2025: long-term evidence. 2026 — review; no funding statement seen.
- Chitturi KR et al. Overview of the 2023 FDA panel meeting on the Symplicity Spyral system. Am Heart J 2024 — meeting overview; no funding information in record.
- FDA. Circulatory System Devices Panel notice of meeting. Federal Register, 21 June 2023 — US regulator notice.
- Haworth PAJ et al. Renal denervation for hypertension management in the UK: a Delphi expert consensus. Heart 2026 — consensus; Medtronic Europe grant.
- SEC EDGAR: Medtronic plc company page — company address; maker.
Educational research reviewed 6 October 2026. This article is not medical advice; talk to a qualified clinician or pharmacist before starting, stopping or combining treatments.
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