Renal denervation decreases resistant hypertension, the results last and the therapy could also find use in managing other diseases. Marc R Sapoval tells interventional radiologists to be part of research in this area, as it could represent “over 80% of your future practice”
Sapoval, professor of clinical radiology and chair of the cardiovascular radiology department at Hôpital Européen Georges-Pompidou in Paris, France, told Interventional News that other specialties like interventional cardiology were also exceedingly interested in the procedure which requires the use of an angiosuite. “There is a huge unmet need out there as the disease burden is very high. Interventional radiologists much get involved and further the research and gain expertise in a technique that could represent a large part of their future practice,” he said.
Speaking at the press conference at the Society of Interventional Radiology’s 36th Annual Scientific Meeting in Chicago, USA, where the results were presented, Sapoval noted that interventionalists have completed the first human randomised controlled trial of therapeutic renal denervation. The researchers say these results confirm that renal denervation may be an effective therapy for reducing—and consistently controlling—resistant hypertension when current medications have failed.
The procedure uses a catheter-based probe inserted into the renal artery which emits high-frequency energy to deactivate the nerves in the renal artery that are linked to high blood pressure.
“Renal denervation, a minimally invasive, effective treatment, appears to be safe in the short term with a low incidence of local complications. Its efficacy to lower blood pressure in patients with resistant high blood pressure will be better evaluated with the results of a subsequent trial,” he said. “After six months, 39% of patients receiving the endovascular denervation treatment had reached the recommended blood pressure level and, overall, 50% of patients showed a measurable benefit of the intervention,” he added.
“Given its impact on the central sympathetic drive, endovascular renal denervation may have applicability in additional disease states such as heart failure, cardio-renal syndrome, hepato-renal syndrome, and in the prevention of progression of chronic kidney disease and hypertension in end-stage renal disease—with the added benefit of helping to raise public awareness on the dramatic burden of this disease,” said Sapoval.
This study targeted only patients with resistant essential hypertension. Sapoval said the causes of high blood pressure can be wide-ranging, such as a benign tumour in the adrenal gland, stenosis of the renal artery, the taking of certain prescription drugs or other factors.
By randomised assignment, 106 adult patients with uncontrolled hypertension received either oral medication or the renal denervation treatment. Six months after the intervention, systolic pressure fell an average of 32mmHg and diastolic pressure fell an average of 12mmHg. A multicentre randomised controlled trial at 24 international sites is now underway.
Sapoval conceded that this was a small study, that the work still experimental, and that renal denervation should be performed only by interventional radiologists on screened patients in strictly controlled academic and/or research settings. However, he noted that it shows great promise for those suffering from resistant hypertension. Sapoval remarked that the patients had a short hospital stay for safety reasons, but that the treatment might possibly be performed in an outpatient clinic in the future.
While the treatment’s efficacy to lower blood pressure in patients with resistant hypertension will be better evaluated with the results of future trials, the interventional radiologist said that some clinical findings (like hypertension in young patients, hypertension after child bearing, etc) can also be used by doctors to determine if other specific diagnostic tests are needed to rule out potential causes of the hypertension.
Call for more publically-funded trials
Sapoval stated that the trial was funded by the catheter and specific generator manufacturer and that there is a huge need for more research in independent hands. To that end, there will be an upcoming nationwide US Food and Drug Administration trial involving more than 100 US-based interventional radiology teams. He also stressed that the published results need confirmation by follow-up with the succeeding trial’s patients after one and two years.
Sapoval hopes that new trials, conducted and funded by public entities, such as the National Institutes of Health in the United States; NICE (the UK National Institute for Clinical Excellence) and the Ministry of Health in France, for example, and similar agencies in other countries, will help researchers to move forward and discern which patients would benefit from this technique, possibly in addition to medication.