One off procedure may be key to reducing treatment-resistant high blood pressure

A clinical trial to evaluate a new treatment for patients with high blood pressure that cannot be controlled with medication (treatment-resistant or refractory high blood pressure) has started at the Mater Private Network in Dublin and four patients have already been enrolled and received a study treatment.

The new treatment which involves a procedure carried out under mild sedation is aimed at patients who have high blood pressure (more than 150-180 over 90 mmHg) that is uncontrolled despite being on up to five medications.

Professor Robert Byrne, Director of Cardiology at Mater Private and Professor of Cardiovascular Research at RCSI , is the principal investigator leading the study at Mater Private Network.

Prof Byrne explained, “This new investigational technique for treating high blood pressure is a minimally invasive procedure and is carried out under mild sedation. We use a special catheter which is inserted through a small incision in the groin and guided to the renal arteries using X-ray guidance. The catheter then delivers a small dose of medical-grade alcohol to the area just outside the renal artery where the nerves that contribute to the increase in blood pressure are located. The alcohol has the effect of deactivating the over-signaling of the nerves and this, in turn, reduces the blood pressure.”

According to Prof Byrne, it is estimated that 10 per cent of people with high blood pressure would have refractory high blood pressure.

He explained that if successful, a patient would only have to undergo the procedure once as it appears to have a long-lasting effect. Patients would still have to continue taking medication for their blood pressure but the hope is that with this procedure it would then be controlled.

If this new treatment proves safe and effective it could also potentially be a step towards a time at some stage in the future when patients with high blood pressure may no longer need to take medication for their condition.

“If the treatment were to prove successful in the group of patients that are resistant to medications, down the line, it might be an option for people who say listen, I just want to control my blood pressure with a single procedure rather than have to take a couple of pills every day. So that is a direction of investigation as well,” Prof Byrne said.

“It could be a step on the road…to eliminate requirements for blood pressure tablets, but we’re still a long way off,” he added.

Prof Byrne said, “high blood pressure is a major health concern in Ireland. International comparisons suggest that Ireland compares poorly to other European countries in terms of detection and treatment of high blood pressure. If left undertreated, it can lead to stroke, heart failure, and kidney disease among many other complications. The standard treatment includes diet, exercise, and prescription medication which can be very effective. However, there are some patients who are still unable to manage their blood pressure within recommended limits with these interventions alone and this clinical trial is an important step toward delivering an alternative treatment.

“Other methods to deactivate the nerves in the renal artery using energy sources such as radiofrequency and ultrasound have been widely investigated in clinical trial settings. This new technique using precise targeted chemical ablation was developed by Ablative Solutions, Inc. and we are one of only two hospitals in Ireland involved in the Target BP I clinical trial for this new technique. “

“Patients who are interested in taking part in the clinical trial may contact our research team at CVRI at cvri@materprivate.ie to see if they qualify,” Prof Byrne added.

The clinical trial for this new treatment for high blood pressure is underway in 100 hospitals in Europe and the United States.