Chemical Block and Electrical Stimulation of the Carotid Body to Treat Refractory Hypertension

Hypertension Clinical Trial

Official title:

Chemical Block and Electrical Stimulation of the Carotid Body to Treat Refractory Hypertension

Clinical Trial Details — Status: Withdrawn

Administrative data

• NCT number: NCT02519868
• Other study ID #: CER 227-15
• Status: Withdrawn
• Phase: N/A
• Start date: August 2015
• Est. completion date: August 2022

Study information

• Verified date: January 2021
• Source: Centre Hospitalier Universitaire Vaudois
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

High blood pressure, also referred to as hypertension, affects about 65 million people in the United States alone. Approximately 25 percent of people with hypertension cannot control their high blood pressure, despite the use of multiple medications. Recently, new evidence has demonstrated that the carotid body (CB) plays a role in essential refractory hypertension, possibly due to a deregulated, enhanced activity of this organ. Animal studies showed that CB de-afferentiation, through carotid sinus nerve denervation, leads to a long-term stable drop in blood pressure in spontaneously hypertensive rats. De-afferentiation may be performed either by injecting local anesthetics or by electrical stimulation. Both techniques are daily used in the operating theater to anesthetize nerves for a wide range of surgical procedures. We hypothesize that blocking CB with local anesthetics will result in a drop of the blood pressure in refractory hypertensive patients. We also want to test the idea that stimulating the CB with an electrical current will mislead the CB and will also result in a drop of the blood pressure.

Description:

High blood pressure, also referred to as hypertension, affects about 65 million people in the United States alone. Approximately 25 percent of people with hypertension cannot control their high blood pressure, despite the use of multiple medications.

Recently, new evidence has demonstrated that the carotid body (CB) plays a role in essential refractory hypertension, possibly due to a deregulated, enhanced activity of this organ. Animal studies showed that CB de-afferentiation, through carotid sinus nerve denervation, leads to a long-term stable drop in blood pressure in spontaneously hypertensive rats. It has been further shown that hypertonicity of the CB leads to a sympathetic hyper-excitation in SH rats and causes an increased vasomotor tone, which in turn contributes to hypertension.

The increased knowledge about the role of the CB in essential hypertension has lead to the development of an implantable (via open surgery) pulse generator, which lead to significant decrease in blood pressure at 12 months. One-year results from 13 patients showed a 39 mmHg average decrease in systolic blood pressure and a 26 mmHg average decrease in diastolic blood pressure in early reports. Beside, the procedure is invasive and requires surgery under general anesthesia.

De-afferentiation may be performed either by injecting local anesthetics or by electrical stimulation. Both techniques are daily used in the operating theater to anesthetize nerves for a wide range of surgical procedures.

We hypothesize that blocking CB with local anesthetics will result in a drop of the blood pressure in refractory hypertensive patients. We also want to test the idea that stimulating the CB with an electrical current will mislead the CB and will also result in a drop of the blood pressure. Preliminary results will shed some light on the mechanism of action of the CB in refractory hypertension and will open the way to new therapeutical approaches such as development of new implantable devices through a transcutaneous approach.

Recruitment information / eligibility

• Status: Withdrawn
• Enrollment: 0
• Est. completion date: August 2022
• Est. primary completion date: August 2022
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 70 Years

Eligibility

Inclusion Criteria:

• 18-70 years of age, inclusive;

• blood pressure not controlled despite 3 different anti-hypertensive drugs;

• minimal body weight of 70 kg.

Exclusion Criteria:

• history of neck surgery or radiotherapy;

• secondary hypertension;

• contraindications to regional anesthesia (e.g., allergy to local anesthetics, coagulopathy, bleeding diathesis, malignancy or infection in the area);

• pregnancy;

• severe respiratory disease;

• inability to understand the informed consent and demands of the study;

• patient refusal.

Related Conditions & MeSH terms

• Hypertension

Intervention

Device:
• Electrical block
Nerve stimulator switched on at an intensity of 5 mA for 15 minutes, with the needle tip positioned close to the carotid bifurcation with the aid of the echography
• Chemical block
Injection of lidocaine 1%, 15 mLs, with the needle tip positioned close to the carotid bifurcation, with the aid of the echography

Locations

Country	Name	City	State
Switzerland	Department of Anesthesia, Centre Hospitalier Universitaire Vaudois and University of Lausanne	Lausanne	Vaud

Sponsors (1)

Lead Sponsor	Collaborator
Eric Albrecht

Country where clinical trial is conducted

Switzerland, 

References & Publications (4)

Alnima T, Scheffers I, De Leeuw PW, Winkens B, Jongen-Vancraybex H, Tordoir JH, Schmidli J, Mohaupt MG, Allemann Y, Kroon AA. Sustained acute voltage-dependent blood pressure decrease with prolonged carotid baroreflex activation in therapy-resistant hypertension. J Hypertens. 2012 Aug;30(8):1665-70. doi: 10.1097/HJH.0b013e3283551f10. — View Citation

Lewington S, Clarke R, Qizilbash N, Peto R, Collins R; Prospective Studies Collaboration. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet. 2002 Dec 14;360(9349):1903-13. Erratum in: Lancet. 2003 Mar 22;361(9362):1060. — View Citation

McBryde FD, Abdala AP, Hendy EB, Pijacka W, Marvar P, Moraes DJ, Sobotka PA, Paton JF. The carotid body as a putative therapeutic target for the treatment of neurogenic hypertension. Nat Commun. 2013;4:2395. doi: 10.1038/ncomms3395. — View Citation

Rosamond W, Flegal K, Furie K, Go A, Greenlund K, Haase N, Hailpern SM, Ho M, Howard V, Kissela B, Kittner S, Lloyd-Jones D, McDermott M, Meigs J, Moy C, Nichol G, O'Donnell C, Roger V, Sorlie P, Steinberger J, Thom T, Wilson M, Hong Y; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics--2008 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2008 Jan 29;117(4):e25-146. Epub 2007 Dec 17. Erratum in: Circulation. 2010 Jul 6;122(1):e10. Kissela, Bret [corrected to Kissela, Brett]. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Blood pressure		15 minutes after electrical block and 15 minutes after chemical block
Secondary	Heart rate		15 minutes after each intervention
Secondary	Presence of paraesthesia		During the procedure
Secondary	Presence of dyspnea		During the procedure
Secondary	Presence of Claude-Bernard-Horner Syndrome		During the procedure
Secondary	Presence of hoarseness		During the procedure
Secondary	Presence of hematoma		During the procedure