The REDUCE HTN: REINFORCE study is testing a new procedure that could treat high blood pressure. This procedure is called renal (kidney) denervation. The study will be evaluating patients that have high blood pressure when they do not take medications. The study will compare the blood pressure of people who undergo the study procedure (renal denervation) with the blood pressure of those who undergo a sham procedure (a renal angiogram that will not include the renal denervation). The study’s purpose is to collect data about the safety and effectiveness of this renal denervation (disabling of kidney nerves) treatment for patients with uncontrolled hypertension.
The Vessix™ Renal Denervation System consists of a catheter (a thin tube) and a radio frequency (RF) generator (power generator). The procedure involves the nerves that surround the blood vessel (artery) that supplies blood to the kidney (kidney artery). The generator sends energy through the kidney artery to disable the surrounding nerves. These nerves have a role in causing the kidneys to keep sodium (salt) in the body and in causing the amount of blood flowing into the filters in the kidney to be lower. These two things, among others, can then cause high blood pressure. By disabling these nerves, the Vessix system aims to reduce the amount of salt kept in the body and therefore reduce blood pressure in the body.
Renal denervation is not a treatment currently used for high blood pressure management in the U.S. The device is investigational in the United States. It is not approved by the U.S. FDA. The sponsor of this study is Boston Scientific Corporation.
The study will include 100 subjects at up to 20 hospitals in the US (about 20 of these subjects will be enrolled at Tufts Medical Center). About 67 people of the 100 total will get the renal denervation procedure (study group) and about 33 people will get a “sham” procedure (control group). People will be randomly selected to one or the other group. The doctor doing the procedure will know which group you are in when he is doing the procedure. Your Study Doctor will tell you whether you received the renal denervation procedure or the sham procedure at your 6 month follow-up visit. Until then, neither you nor your Study Doctor will know which procedure you received. The sham procedure is done to get data that is not influenced by knowing what procedure you received.
- Resting systolic blood pressure: 150 -180 mmHg (after four weeks without blood pressure medications).
- Average systolic blood pressure measured over a 24 hour period of normal activity: 135-170 mmHg (after four weeks without blood pressure medications).
- Subject must have a main artery supplying each kidney, and each artery must have a diameter of 3-7 mm, and a length of at least 20.0 mm
- Severe heart failure or severe heart valve disease
- Severe kidney disease or kidney transplant
- Bleeding problems
- 1-hour initial screening visit: medical history review, demographics, physical exam, blood pressure measurements
- A small ambulatory blood pressure monitor (ABPM) will be worn on the arm for 24 hours of normal activity.
- Medication washout: If you still qualify and are currently on blood pressure medicine, you will be asked to stop taking these medicines. During this ‘wash-out’ phase, which lasts 4 weeks, your study doctor will monitor your blood pressure to make sure it does not get too high.
- Blood sample: After washout, you will have a blood draw of about 20ml, or 4 teaspoons.
- Quality of life questionnaire.
- Pregnancy test.
- Renal computed tomographic angiography (CTA): You will have a special type of imaging conducted that will look at the size, length and basic appearance of your kidneys and the blood vessels supplying your kidneys to make sure they are okay for the renal denervation procedure (the right size and without blockages).
- Renal Angiography – If the CTA shows that you are eligible, then Renal Angiography will be scheduled. This is the final test to ensure it is safe for you to receive the procedure. The Study Procedure Doctor will insert a tube into an artery in your right or left groin, and then pass a catheter through this tube up to the level of the kidney arteries. X-ray (contrast) dye will be injected into both kidney arteries to ensure they are safe to have the study device placed and applied. If the angiogram shows there are no problems, then you will be immediately randomized to receive either the Renal Denervation Procedure or the Sham procedure. If angiography shows you are not eligible, the tubes will be removed and the opening in the groin artery will be sealed. You will not receive further procedures and will not need to make additional study visits.
Renal Denervation Procedure: If you are placed in the RD Procedure group, the Study Procedure Doctor will then insert the Vessix study device through the groin tube. Using fluoroscopy (x-ray films), the study device will be positioned in one of the kidney arteries. A radio frequency pulse will be applied to the artery to indicate nearby nerves. Contrast dye will be injected as needed to correctly place the study device. Once the renal denervation catheter is in place, energy will be delivered through the artery wall to disable the surrounding kidney nerves. This procedure will be repeated on the opposite side so that both kidneys are treated. During the procedure, the study staff will record information about the procedure, medications administered and any difficulties you may experience. After the procedure, the hole in the artery will be sealed, and you typically will stay in the hospital overnight for observation. The angiography and study procedure will take about 1 hour in total to complete.
Sham Procedure: If you are placed in the control group, the Vessix catheter will not be inserted and the nerves will not be disabled. Otherwise, the steps will be similar. The angiography and sham procedure also take about 1 hour to complete.
Follow-up: The research study requires all subjects to be seen by their Study Doctor at discharge, 2 weeks, 4 weeks, 8 weeks and then 3, 4, 5, 6, 12, 18, 24, 30 and 36 months after the procedure. Follow up visits will last approximately 1 hour.
The list below outlines the tests and evaluations to be conducted during follow-up visits:
- Physical exam and adverse event assessment, at discharge and at each follow-up visit.
- Blood tests: Discharge, 8 Weeks, 6 Months, 12 Months, 24 Months, 36 Months.
- Blood pressure management: At least 3 sitting measurements and one standing measurement will be taken at discharge and at each follow-up visit. If your blood pressure is too high, your Study Doctor will prescribe you medication and will recheck your blood pressure more frequently until it has reached a normal value.
- 24 Hour Ambulatory Blood Pressure Monitoring (at home): 4 Weeks, 8 Weeks, 6 Months, 12 Months.
- Quality of Life Questionnaire: 8 Weeks, 6 Months, 12 Months, 24 Months, 36 Months.
- At your 6 month follow up visit, you will undergo a Renal Duplex Ultrasound, a test that uses sound waves to look at your kidneys. An angiogram or CTA may also be required, based on the ultrasound results.
You will be followed for 36 months (3 years) after the procedure. Your participation in the study will be complete after your 36 month follow-up visit.