REDUCE-HTN: Vessix renal denervation system reduced BP at 6 months

SAN FRANCISCO — Patients with treatment-resistant hypertension treated with the Vessix Renal Denervation System experienced significant and sustained reductions in BP at 6 months, according to data presented at TCT 2013.

The device (Boston Scientific) uses balloon-based technology that ablates the renal artery via simultaneous activation of bipolar radiofrequency electrodes, Horst Sievert, MD, of Cardiovascular Center Frankfurt, Germany, said during a presentation.

Sievert reported interim 6- and 12-month combined results from the first-in-human (n=18) and postmarket (n=128) REDUCE-HTN studies. All patients (mean age, 58.5 years; 61% men; 92.5% white) had uncontrolled hypertension despite taking at least three antihypertensive medications (first-in-human group, systolic BP ≥160 mm Hg; postmarket group, systolic BP ≥160 mm Hg/diastolic BP ≥90 mm Hg). His presentation included analysis of 139 patients completing 6-month follow-up and 41 patients completing 12-month follow-up.

Efficacy endpoints included reduction of office BP and reduction of 24-hour ambulatory BP at 6 months. Acute safety endpoints include renal artery dissection or perforation occurring during the procedure and requiring stenting or surgery, renal artery infarction or embolus, cerebrovascular accident at time of procedure, MI at time of procedure and sudden cardiac death at time of procedure. Long-term safety endpoints included renal stenosis requiring intervention and requirement of duplex ultrasound at 6 months documenting absence of flow limiting stenosis in the renal artery.

Office BP reductions

At 6 months, the mean reduction in systolic office BP was –24.6 mm Hg and mean reduction in diastolic office BP was –10.3 mm Hg (P<.0001). At 12 months, mean reduction in systolic office BP was –29.6 mm Hg and mean reduction in diastolic office BP was –13.6 mm Hg (P<.0001).

The rate of patients experiencing a reduction in office systolic BP >5 mm Hg was 84.9% at 6 months and 85.4% at 12 months. Office-based systolic BP <140 mm Hg was attained in 19% of patients at 6 months and 34% of patients at 12 months.

The device was also associated with reductions in 24-hour ambulatory BP at 6 and 12 months, Sievert said. At 6 months, the mean 24-hour ambulatory systolic BP reduction was –8.5 mm Hg (P<.01) and mean 24-hour ambulatory systolic BP reduction was –5.9 mm Hg (P<.01). The reduction was maintained at 12 months (systolic, –11.2 mm Hg; diastolic, –6.3 mm Hg; P<.01).

Thirty-two percent of patients had ambulatory systolic BP <140 mm Hg at 6 months and 44% at 12 months. The reduction “was greatest for patients with higher baseline pressure,” Sievert said. “That is consistent with findings from other studies … and something we wanted to see.”

Subgroups attain lower levels

Sievert said the device reduced BP in the following subgroups: men, women, those with accessory renal arteries, diabetics and those aged 65 years or older.

No acute safety events were reported and procedure-related adverse events occurred at a 5.5% rate. “One patient developed renal artery stenosis and received treatment for it,” Sievert said. “All of the other events were more or less access-related.” – by Erik Swain

For more information:

Sievert H. Featured Clinical Research I. Presented at: TCT 2013; Oct. 27-Nov. 1, 2013; San Francisco.

Disclosure: Sievert reports conflicts of interest with several device and pharmaceutical manufacturers.