The SPYRAL AFFIRM Clinical Trial at the John Radcliffe Hospital, Oxford

What is the SPYRAL AFFIRM clinical trial?

The main purpose of the SPYRAL AFFIRM study is to evaluate the long-term effects of the Symplicity Spyral system for renal denervation in people with varying severity of hypertension and associated health issues.

The trial is global, however in Oxford the study is being led by Dr Giovanni Luigi De Maria at the John Radcliffe Hospital, Oxford.

What are the eligibility criteria?

To be considered for the trial, you must be between 18 and 80 years of age and have a baseline systolic blood pressure of at least 140 mmHg.

What does the trial involve?

After passing some baseline health checks, if eligible, you will undergo the renal denervation procedure. Your blood pressure and other health markers will then be assessed at 3, 6, 12, 24 and 36 months after this.

You will be required to take your blood pressure at home for at least seven days prior to each post procedure appointment and attend an appointment at the John Radcliffe at the required intervals for hospital blood pressure checks. Blood samples will also be taken at the pre-procedure stage and at 12 months post procedure.

Registration, all procedures, and follow-up appointments are at the John Radcliffe Outpatient Cardiology Clinic, and participation in the trial is free.

How do I sign up?

You will need to be assessed by a cardiologist to determine your suitability and then go through a screening selection process. The first step is to book a hypertension review in the usual way, and then discuss this option with your consultant.

Book Your Hypertension Review

If you have been diagnosed with hypertension and have been taking medication, yet your hypertension is still outside normal limits, you may be eligible for the RDN procedure. Get in touch and book a hypertension review to find out.

Renal Denervation for Hypertension: your questions answered

Here you’ll find further information on the renal denervation (RDN) process in general. For specific concerns or questions relating to your hypertension, you should speak with your GP or consultant cardiologist.

How long will I be in hospital?

Some people can go home the same day of the procedure, some may need an overnight stay.

Is Renal Denervation Treatment Right For Me?

Generally, RDN is suitable for those who have uncontrolled medium to high hypertension and are already on several types of medications, or have experienced side effects from most blood-pressure medications. Your GP or consultant cardiologist will help you decide whether this procedure is right for you.

How long is the recovery period?

Usually about a week, after which many people return to their normal activities. Your doctor will monitor you and let you know when you are ready.

What happens after the procedure?

Generally, you may have two follow-up appointments; one with the consultant who performed your procedure, and one with your GP.

Are there any possible complications?

Renal denervation has a well demonstrated safety-profile. However as in any invasive test/procedure, complications can occur. The cardiologist performing the procedure, or your GP, can discuss this in more detail.

Injury to the kidney or narrowing of the renal artery are possible serious complications, though extremely rare with an incidence reported in clinical studies below 0.5%.

The most common side effect associated with renal denervation is bleeding at the entry site (groin) where the puncture is made to insert the catheter to perform the procedure. In clinical studies no major bleeding complications have been described.

The occurrence of bruising/haemathoma at the entry point though is not uncommon. This can sometimes be source of discomfort for a few days/weeks after the intervention, but it usually responds well to painkillers and tends to resolve spontaneously over time.

How long does the procedure take?

This is variable according to the vessels’ anatomy, but an average procedure can take around 60 minutes.

Will I be awake during RDN treatment?

The procedure can be painful at the stage when energy is delivered to disconnect the nervous fibres.  For this reason, it is performed under local anaesthesia, analgesia, and deep sedation, meaning that the patient is usually not awake during the procedure, but still able to breathe spontaneously without need of assistance of specific medical equipment. The level of awareness during the procedure can vary from individual to individual, with most patients typically sleeping throughout; though there are rare scenarios when some degree of vigilance remains.

Will my blood pressure drop immediately?

The short answer is no, as the procedure aims at reprogramming the connections between the brain and the kidney and this cannot happen immediately. Roughly, the effect of the procedure becomes manifest between 3 and 6 months, even though there have been cases with quite immediate response after a few days.

Please keep in mind, like for any therapy, there is roughly a 20% chance of absence of response. Unfortunately, we currently cannot predict ahead of time who will be and who won’t be a good responder to this treatment.

How long does the effect on blood pressure last?

According to the available data, the effect on blood pressure seems to be well maintained over time and well reflected by the observation that nerves around renal arteries do not regrow. The most solid data confirmed a maintained lowering blood pressure effect at least up to 3 years, but data supporting maintained effect on blood pressure beyond 3 years are growing.

If all goes well, will I be able to stop taking medications for hypertension?

The aim of renal denervation is not discontinuing the tablets, but to ensure optimal blood pressure control, as this is what drives a reduction in the risk of stroke or heart attack.

There is however a good chance that the dose or number of tablets might be decreased after the procedure. However, the procedure is considered a success even when a patient, who had initially poor blood pressure control on medications, achieves optimal blood pressure values afterwards, even though this requires taking all or some of the initial medications.

An extra benefit, possibly associated with the procedure, is that the effect on blood pressure is always ON when compared to medications that have an effect on blood pressure only when the patient remembers to take his/her tablets.