Early Results with the Rheos® System
Early stage studies on the Rheos Systemincluded 61 patients with severe uncontrolled high blood pressure. These patients were taking at least 3 blood pressure medicines. Even with medicine, they still had high blood pressure. Some of these patients also had early-stage heart failure.
Data on the impact of the Rheos System on the heart was collected for 21 of these patients. Most of these 21 patients experienced positive results with the Rheos System such as2:
- Reduced size and thickness of the heart
- Improved heart function
- Reduced blood pressure
* Heart size and thickness are determined using a left ventricular mass index.
Bisognano JD. JACC 2009;53(10) Suppl A, A188.
Twelve (51%) of the 21patients on the above graph had hearts of normal size and thickness after one year with the Rheos System. Before getting the Rheos System only 3 (15%) patients had hearts of normal size and thickness.
Two of the 21 patients experienced events such as: device movement, high blood pressure episodes, and surgical complications. All events were resolved.
Partial Results of Larger Study with the Rheos® System
A larger ongoing clinical trial, called the Pivotal study, has collected data on 322 patients who were on 3 or more anti-hypertensive medications and still had severe high blood pressure. The purpose of this study is to evaluate whether the device (1) is effective at lowering blood pressure and (2) is safe. Subjects were randomized (like flipping a coin) to having the device ON one month after the implant or OFF for 7 months after the implant. At 7 months all 322 patients had the system turned ON. This study is still in progress and data from all patients is not yet available.
Blood pressure data at one year after having the device turned on has been collected for 110 patients. These patients experienced similar blood pressure drops than patients from the early stage studies after 1 year of therapy (see graph below).
Eighteen patients in the early trials have now been followed for four years, and they have experienced an average systolic blood pressure drop of 53 mmHg after four years.
Data from the large study also shows that at 6 months, patients with the Rheos System turned ON experienced large average blood pressure drops compared to before surgery. However, patients with the device turned OFF also experienced blood pressure drops that were higher than expected. Because of this, the Pivotal study will likely not be able to prove that more patients with the system turned ON for 6 months reached a 10 mmHg blood pressure drop when compared with patients with the system turned OFF.
In the large study, the rates of the serious unresolved problems were: injury to nerves in the neck (4.8%), surgical complications (1.1%), stroke (0.4%) and miosis (narrowing of the pupil of the eye) (0.4%). There were also serious problems that resolved without lasting consequences to patients, the most common of which were: injury to the nerves in the neck (4.4%), surgical complications (4.4%), respiratory (breathing) complications (2.2%), wound complications (1.9%) and surface wound infections (1.9%).
The results of all of the above studies offer hope for people with heart failure. Now a study with a larger number of patients with heart failure is needed to evaluate the safety and effectiveness of the Rheos System to treat heart failure patients.
2. Bisognano JD, de Leeuw P, Bach DS, Kaufman CL, Eric G. Lovett, for the DEBuT-HT and Rheos Feasibility Investigators. Improved Cardiac Structure and Diastolic Flow Velocities in Early-Stage Heart Failure with Chronic Treatment Using an Implantable Device: Results from European and United States Trials of the Rheos® System. JACC 2009:53(10) Supp A, A188.
CAUTION: Investigational device. Limited by Federal (or United States) law to investigational use.