1University Hospital Maastricht and Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands
2University of Rochester Medical Center - Strong Heart and Vascular Center, Rochester, USA
3University of Michigan - Department of Internal Medicine, Ann Arbor, USA
4CVRx Inc., Minneapolis, USA
Objective: Left ventricular (LV) hypertrophy is a common co-morbidity of patients with resistant hypertension (HTN). Abnormal cardiac structure and function may contribute to the reduced functional capacity observed in HTN. Baroreflex Activation Therapy (BAT®), delivered by the Rheos® System, has previously been shown to improve cardiac structure and function. Therefore, the objective of this study was to determine if BAT improves functional capacity in resistant HTN patients.
Design and Methods: Patients were implanted with the Rheos System, which is an implantable device with electrodes placed on the carotid sinus that chronically activate the carotid baroreflex. Patients had Stage II HTN (systolic BP >160 mmHg) and were taking > 3 anti-HTN drugs including at least one diuretic. Follow-up occurred after 3 and 12 months of BAT. The six-minute hall walk (6-MHW) test was administered to assess functional health. Echocardiography was performed and analyzed at a blinded core lab.
Results: 21 subjects (Age 53.7 ± 10.1 yr) had complete paired data through the follow-up period. After 12 months of BAT, a statistically and clinically significant improvement in 6-MHW distance and left ventricular mass index was observed (Table). Left ventricular stroke work was significantly reduced after 3 and 12 months of BAT. No change in BMI or medication load occurred during the follow-up period.
Conclusions: In patients with resistant HTN and aggressive background medical therapy, BAT resulted in chronic improvements in functional capacity. Improvements in cardiac structure and function were concurrently observed.