Renal Denervation Systems Show Persistent Reductions in BP

San Francisco, CA—Two renal denervation systems have demonstrated safe, efficient and persistent reductions in blood pressure in patients with treatment-resistant hypertension, according to data presented at TCT 2013.

Researchers reported interim 6-month and 12-month data from the REDUCE-HTN study and 18-month data from the EnligHTN-1 study. 

REDUCE-HTN 

In REDUCE-HTN, the balloon-based Vessix (Boston Scientific) radiofrequency system reduced mean office-based systolic and diastolic BP at 6 months, and these reductions were sustained for patients completing 12-month follow-up (see Figure), Horst Sievert, MD, of Cardiovascular Center Frankfurt, Germany, said.

Vessix also reduced mean 24-hour ambulatory BP at 6 months (n=67; –8.5 mm Hg/–5.9 mm Hg; P<.01) and 12 months (n=25; –11.2 mm Hg/–6.3 mm Hg; P<.01).

Office-based systolic BP <140 mm Hg was attained in 19% of patients followed through 6 months and 34% of patients followed through 12 months. 

Ambulatory systolic BP <140 mm Hg was attained in 32% of patients followed through 6 months and 44% of patients followed through 12 months. The effect “was greatest for patients with higher baseline pressure,” Sievert said. “That is consistent with findings from other studies … and something we wanted to see.”

There were no acute safety events and the rate of procedure-related adverse events was 5.5%. “One patient developed renal artery stenosis,” Sievert said. “All of the other events were more or less access-related.”

The subgroups in which Vessix reduced mean office BP at 6 months included those with accessory renal arteries (P<.0005), men (P<.0001), women (P<.0001), patients with diabetes (P<.0001) and those aged 65 years or older (P<.0001).

EnligHTN-1 

Similarly, at 18 months, the EnligHTN system (St. Jude Medical) reduced mean baseline office BP (n=44; –24 mm Hg/–10 mm Hg; P<.0001).

Stephen G. Worthley, PhD, of Royal Adelaide Hospital, Adelaide, Australia, said there were no serious peri-procedural events and only four serious device/procedure events through 18 months. 

Additionally, 77% of patients had a reduction in office systolic BP >10 mm Hg, and 68% had office systolic BP <160 mm Hg despite a mean baseline of 176 mm Hg. “There was no significant change between 6, 12 and 18 months, attesting to the robustness of this BP reduction out to 18 months,” Worthley said.

The EnligHTN device was not associated with any clinically significant changes in renal function from baseline to 18 months, including eGFR (87 vs. 77 mL/min/1.73m²), serum creatinine (78 vs. 86 mmol/L), cystatin C (1.14 vs. 1.1 mg/L), and urine albumin-to-creatinine ratio (167.6 vs. 131 mg/g).

Disclosures:

Sievert and Worthley report conflicts of interest with several device and pharmaceutical manufacturers.