Renal Denervation Effective Despite Extra Renal Arteries
ISTANBUL—The presence of extra renal arteries probably does not justify excluding patients with treatment-resistant hypertension from undergoing catheter-based renal sympathetic denervation, Dutch investigators said at the 50th Congress of the European Renal Association-European Dialysis and Transplant Association.
“Treatment-resistant hypertensive patients with more than one renal artery in either kidney have been deemed ineligible for renal denervation out of concern that the procedure might be less effective and less safe in this population,” said Eva E. Vink, MD, who is studying renal denervation as part of a PhD project in the department of nephrology of the University Medical Center in Utrecht, The Netherlands. “However, we found good blood pressure-lowering results at six months with renal denervation in patients with multiple renal arteries whom we had determined to be suitable because at least one of their renal arteries was greater than 4 mm in diameter and greater than 20 mm in length.”
Patients with an multiple artery smaller than these dimensions were only treated in the so-called suitable artery. Patients with multiple arteries with suitable dimensions were also treated in the additional artery.
What's more, the study found that renal denervation was safe, with outcomes in patients with multiple arteries as good as outcomes in patients with solitary renal arteries.
In her series of patients referred for renal denervation, 34% of patients had multiple renal arteries.
Dr. Vink presented six month results from 40 patients with solitary renal arteries and 16 patients with multiple renal arteries who underwent renal denervation.
One reason that patients with multiple renal arteries have been excluded from renal denervation in clinical practice is that they have been excluded from clinical trials. The reason for exclusion is that the diameter of the multiple renal artery is often smaller than the diameter of the main artery, and it is thought that treating only one artery with renal denervation in a patient with multiple renal arteries may be less effective.
Study participants had an office systolic blood pressure (BP) of 160 mm Hg or higher and stable use of three or more three antihypertensive medications. In all patients, secondary forms of hypertension and white coat hypertension had been excluded. The main outcome measure was office BP at six months.
At six-months, mean office BP had decreased in the entire group from 202 mm Hg at baseline to 171 mm Hg at six months. The mean decrease in systolic BP was similar in the two groups (-33 mm Hg for solitary arteries and -29 mm Hg for the group with arteries).
Dr. Vink observed no change in estimated glomerular filtration rate in the entire group or in the subgroups.
Some patients had a BP reduction large enough to permit a lower stage of hypertension classification and treatment.