Acute Response to Unilateral Unipolar Electrical Carotid Sinus Stimulation in Patients With Resistant Arterial Hypertension

Abstract

Bilateral bipolar electrical carotid sinus stimulation acutely reduced muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in patients with resistant arterial hypertension but is no longer available. The second-generation device utilizes a smaller unilateral unipolar disk electrode to reduce invasiveness while saving battery life. We hypothesized that the second-generation device acutely lowers BP and MSNA in treatment-resistant hypertensive patients. Eighteen treatment-resistant hypertensive patients (9 women/9 men, 53±11 years, 33±5 kg/m2) on stable medications have been included in the study. We monitored finger and brachial BP, heart rate (HR), and MSNA. Without stimulation, BP was 165±31/91±18 mmHg, HR was 75±17 bpm, and MSNA was 48±14 bursts/min. Acute stimulation with intensities producing side effects that were tolerable in the short term elicited interindividually variable changes in systolic BP (SBP: −16.9±15.0 mmHg, range: 0.0 to −40.8 mmHg, p=0.002), HR (−3.6±3.6 bpm, p=0.004), and MSNA (−2.0±5.8 bursts/min, p=0.375). Stimulation intensities had to be lowered in 12 patients to avoid side effects at the expense of efficacy (SBP: −6.3±7.0 mmHg, range: 2.8 to −14.5 mmHg, p=0.028; HR: −1.5±2.3 bpm, p=0.078; comparison against responses with side effects). Reductions in diastolic BP and MSNA (total activity) were correlated (r2=0.329, p=0.025). In our patient cohort, unilateral unipolar electrical baroreflex stimulation acutely lowered BP. However, side effects may limit efficacy. The approach should be tested in a controlled comparative study.

Baroreflex activation therapy in patients with prior renal denervation

“…Titrating BAT neo to chronically tolerable levels may be associated with reduction in efficacy compared with BAT rheos [45]. Thereby, it must be considered that all patients in the present study were treated with BAT neo.…”

“…Recently, it was suggested that BAT rheos and neo may differ in terms of acute efficacy [45]. Titrating BAT neo to chronically tolerable levels may be associated with reduction in efficacy compared with BAT rheos [45].…”

Prolonged Baroreflex Activation Abolishes Salt-Induced Hypertension After Reductions in Kidney Mass

“…4–5 Notably, a recent acute study in patients employing 2 min periods of unilateral carotid sinus activation suggested that the new electrode design may diminish efficacy and tolerability. 49 However, this has not been our experience when using the Barostim Neo system during chronic bilateral carotid sinus activation in canines. 33,50 Randomized controlled trials are needed to thoroughly evaluate whether the Barostim Neo electrode system may have clinical utility in managing RHT.…”

Resistant Hypertension

“…In the first study, Heusser et al found that acute stimulation of the carotid sinus via a unilaterally implanted electrode, acutely lowered both systolic and diastolic BP in 18 patients with uncontrolled resistant hypertension. 28 There was not a significant change in muscle sympathetic nerve activity (MSNA), but overall, reductions in diastolic BP did correlate with reductions in MSNA. There was a wide range in the magnitude of BP and MSNA reduction following acute carotid sinus stimulation and about two-thirds of the subjects experienced stimulation-related adverse effects, necessitating reduction in the stimulation intensity.…”