Evaluating the long-term outcomes of catheter-based renal artery denervation in patients with uncontrolled hypertension.

This study reported the long-term outcomes of catheter-based renal artery denervation (CB-RD) in patients with resistant or uncontrolled hypertension [high blood pressure (BP)]. The data showed that over the long-term CB-RD was safe and had significantly greater reductions in BP and better BP control compared with a sham control in these patients.

Hypertension or high BP is a condition that can lead to serious health complications and/or death. Several strategies are used to manage hypertension. Lifestyle modifications and medication can be used to lower BP. Some patients may still find it difficult to control BP. This is called uncontrolled or resistant hypertension. One option for these patients is surgery.

Renal (kidney) denervation (RD) is a new surgical approach to managing BP. It involves using a catheter to deliver a high-energy pulse that kills the nerves near the renal artery. This reduces BP in the kidneys. Studies have shown that over a short-term period, catheter-based RD (CB-RD) is effective in reducing BP in patients with uncontrolled hypertension. However, the long-term outcomes of CB-RD in patients with uncontrolled hypertension are still unknown.

This study involved 535 patients with uncontrolled hypertension. Patients were randomly assigned into 2 groups. Group 1 included 364 patients who received CB-RD delivered by the Symplicity Spyral system. Group 2 included 171 patients who received the sham (control) procedure. Patients were followed-up for 36 months after the procedure.

The office systolic blood pressure (SBP; BP when the heart beats) was reduced by 26.4 mm Hg in group 1 versus 5.7 mm Hg in group 2. The 24-hour ambulatory (moving) blood pressure (ABP) was reduced by 15.6 mm Hg in group 1 versus 0.3 mm Hg in group 2. These differences were statistically significant.

A better BP control was achieved in 18% of the patients in group 1 versus 9% of the patients in group 2. This difference was statistically significant. 

Side effects were similar between the two groups (15% in group 1 versus 14% in group 2).

This study concluded that over the long-term CB-RD was safe and had significantly greater reductions in BP and better BP control compared with a sham control in patients with uncontrolled hypertension.

The number of patients in the control group was very small. The study did not evaluate the risk of cardiovascular events. This study was funded by Medtronic, manufacturer of Symplicity Spyral system which is a CB-RD procedure.