Abstract 15717: Acute On/Off Effects of Baroreceptor Activation Therapy (BAT) on Blood Pressure After Long-Term Therapy for Resistant Hypertension: Single-Center Experience With the Barostim Neo System
Background: Nonpharmacologic therapies have recently become available that can lower blood pressure (BP) when medical therapy is not sufficient. Chronic baroreceptor activation therapy (BAT) has been shown to reduce BP for at least 6 months using the Barostim neo system, which allows unilateral stimulation with a minimally invasive implantation. However, it is not known whether long-term chronic baroreceptor stimulation influences the acute responsiveness to stimulation. Therefore we determined the on/off effects of BAT at different time points after implantation.
Methods: Resistant HTN patients (n=12) were enrolled in an open-label, single-arm evaluation of Barostim neo after exclusion of secondary hypertension. Initial eligibility criteria for barostim implantation were systolic BP ≥ 140mmHg despite stable (≥ 4 weeks) medical therapy consisting of ≥ 3 antihypertensive drugs including at least one diuretic. For on/off testing three BP measurements were performed between 1 and 25 months after activation (mean 13.6 months): after 5 min rest with activated device, 5 min after deactivation of the device and 5 min after reactivation of the device.
Results: Before BAT mean office cuff BP was 178.2 ± 26.6 mmHg (systolic BP; SBP) over 99.2 ± 19.0 mmHg (diastolic BP; DBP). At the time of on/off testing BP was reduced to 148.8 ± 26.5 mmHg (SBP; p=0.01) over 87.8 ± 20.3 mmHg (DBP; p=0.09).
On deactivation of the device BP increased by 11.3 ± 15.6 mmHg (systolic BP; p=0.03) and 6.3 ± 11.8 mmHg (diastolic BP; p=0.09) and decreased after reactivation by 15.3 ± 18.0 mmHg (SBP; p=0.01) and 8.1 ± 10.8 mmHg (DBP; p=0.03). There was no correlation between duration of chronic BAT and systolic or diastolic on/off response (all p>0.1).
Conclusions: After 13.6 months of follow-up, unilateral baroreceptor activation therapy (BAT) reduces BP consistently in patients with resistant HTN. The acute on/off response to BAT is the same in patients after long-term treatment as in those with recent device activation. Thus, no evidence of tolerance over time to chronic BAT can be found, indicating that this therapy is fully effective in the long-term treatment of patients with resistant HTN.
- © 2013 by American Heart Association, Inc.