Long-term effects of baroreflex activation therapy: 2-year follow-up data of the BAT Neo system.

Objective: Baroreflex activation therapy (BAT) reduces office blood pressure (BP) in patients with resistant hypertension (HTN). Whereas sustained effects from the BAT Rheos device have already been reported, no long-term data on 24-h ambulatory BP (ABP) are currently available for the unilateral BAT Neo device.

Methods: Patients treated with the BAT neo device for resistant hypertension were prospectively included into this observational study. Office and ABP measurements were performed before BAT implantation as well as 6, 12 and 24 months after initiation of BAT.

Results: A total of 60 patients with resistant HTN (office BP 172 ± 25/90 ± 17 mmHg, 24-h ABP 150 ± 16/80 ± 12 mmHg, median of antihypertensive drugs 7 (IQR 6-8)) were included. After 24 months, there was a significant reduction of - 25 ± 33/- 9 ± 18 mmHg (n = 50, both p < 0.01) in office BP and - 8 ± 23/- 5 ± 13 mmHg (n = 46, both p = 0.02) in 24-h ABP, while the number of antihypertensive medications was reduced to a median of 5 (4-6) drugs (p < 0.01). Patients with isolated systolic HTN (ISH) experienced a BP-lowering effect in office BP, but not in ABPM at month 24. Using unadjusted BP values, BAT seems to be more effective in combined hypertension (CH) than in ISH. After adjustment for baseline BP values, there was no significant difference in BP reduction between ISH and CH patients. Ambulatory SBP at baseline was the only independent correlate of BP response at month 24.

Conclusion: BAT reduced office BP and improved relevant parameters of ABP, which is associated with a high cardiovascular risk, in patients with resistant HTN, whereas, after adjustment for baseline BP, BP reduction was not different in patients with CH compared with patients with ISH. However, randomized controlled trials are needed to confirm the effects of BAT on 24-h ABP.