An implantable carotid sinus stimulator for drug-resistant hypertension: surgical technique and short-term outcome from the multicenter phase II Rheos feasibility trial.
BACKGROUND
A large number of patients have hypertension that is resistant to currently available pharmacologic therapy. Electrical stimulation of the carotid sinus baroreflex system has been shown to produce significant chronic blood pressure decreases in animals. The phase II Rheos Feasibility Trial was performed to assess the response of patients with multidrug-resistant hypertension to such stimulation.


METHODS
The system consists of an implantable pulse generator with bilateral perivascular carotid sinus leads. Implantation is performed bilaterally with patients under narcotic anesthesia (to preserve the reflex for assessment of optimal lead placement). Dose-response testing at 0 to 6 V is assessed before discharge and at monthly intervals thereafter; the device is activated after 1 month's recovery time. This was a Food and Drug Administration-monitored phase II trial performed at five centers in the United States.


RESULTS
Ten patients with resistant hypertension (taking a median of six antihypertensive medications) underwent implantation. All 10 were successful, with no significant morbidity. The mean procedure time was 198 minutes. There were no adverse events attributable to the device. Predischarge dose-response testing revealed consistent (r = .88) reductions in systolic blood pressure of 41 mm Hg (mean fall is from 180-139 mm Hg), with a peak response at 4.8 V (P < .001) and without significant bradycardia or bothersome symptoms.


CONCLUSIONS
A surgically implantable device for electrical stimulation of the carotid baroreflex system can be placed safely and produces a significant acute decrease in blood pressure without significant side effects.
Illig
Karl A
KA
Division of Vascular Surgery, University of Rochester Medical Center, Rochester, NY 14642, USA. Karl_Illig@urmc.rochester.edu
Levy
Mark
M
Sanchez
Luis
L
Trachiotis
Gregory D
GD
Shanley
Charles
C
Irwin
Eric
E
Pertile
Terry
T
Kieval
Robert
R
Cody
Robert
R
D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D017704:Baroreflex; D001794:Blood Pressure; D002346:Carotid Sinus / Q000294:innervation / Q000601:surgery*; D004351:Drug Resistance; D004599:Electric Stimulation Therapy / Q000295:instrumentation*; D004567:Electrodes, Implanted; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
D000959:Antihypertensive Agents