Important Safety Information

Talk with your doctor about potential risks associated with the procedure and study.

The primary risks of the renal denervation procedure are similar to the risks of all diagnostic procedures requiring catheterization of the arteries of the body. The following are potential risks of the catheterization procedure (including renal angiogram):

Uncommon < 10% (less than 1 in 10 chance), temporary and not severe unless otherwise indicated

• Nausea or vomiting
• Complications associated with the use of any pain or anxiety medication during or after the procedure
• Complications at catheter insertion site in the groin
  • Pain
  • Bruising
  • Hematoma (collection of blood outside a blood vessel)

Rare < 1% (less than 1 in 100 chance), temporary and not severe unless otherwise indicated

• Heart rhythm disturbances, including bradycardia (a slowed heart rate)
• Embolism - Formation and dislodgement of a blood clot or dislodgement of cholesterol/plaque within the blood vessel, which travels downstream into small vessels, blocking blood flow and causing temporary or permanent damage to organs in the body. Clots are known to cause heart attack, stroke, kidney damage, or threaten circulation to arms or legs and may ultimately lead to incapacitation or death.
• Complications at catheter insertion site in the groin
  • Pseudoaneurysm (injury to the artery wall resulting in a build-up of blood under the skin)
  • Arteriovenous fistula (an abnormal connection or passageway between an artery and a vein)
• Vascular complications requiring surgery
• Perforation or dissection (a hole or tear in your blood vessel) of a blood vessel, such as the renal artery
• Complications associated with the contrast agent used during the procedure, e.g., serious allergic reaction or reduced kidney function

Very Rare < 0.1% (less than 1 in 1000 chance)

• Complications at catheter insertion site in the groin
  • Infection
  • Significant bleeding
• Retroperitoneal bleeding (bleeding into the abdominal space)
• Cardiopulmonary arrest
• Death

There are additional risks that could possibly be associated with the denervation procedure/response to treatment. These complications have not yet been quantified. These potential risks may include:

• Pain – during or after the procedure that may require treatment with pain medications.
• Damage to one or both kidneys, loss of kidney function, and/or need to remove a kidney. If severe enough, this could require dialysis.
• Damage to the blood vessel wall or other body structures from the delivery of energy, e.g., renal artery stenosis (narrowing of blood vessel), spasm, or aneurysm (ballooning of blood vessel wall).
• Hypertension (blood pressure too high)
• Hypotension (blood pressure too low)
• Hematuria (blood in urine)
• Hemorrhage (significant blood loss)
• Proteinuria (increased amount of protein in urine)
• Allergic and/or adverse reaction from insertion of foreign body (i.e., catheter)
• Electrolyte disturbances (e.g., changes in the amount of salt in blood/urine)
• Skin burn

There are additional risks that could possibly be associated with the tests and procedures performed for the clinical study. These potential risks are described below:

If you are in the SPYRAL HTN-OFF MED Study, the risks associated with being off blood pressure medications for approximately 4 months (collectively, these 7 risks are the "Off Meds Risks") include:

• Angina (chest pain, pressure or squeezing)
• Myocardial Infarction (improper blood flow to the heart)
• Atrial Fibrillation (abnormal heart rhythm)
• Heart Failure
• Pulmonary Edema (fluid accumulation in the air spaces of the lungs)
• Stroke (disturbance in the blood supply to the brain)
• Death

The risks associated with not having blood pressure adequately controlled for the 6 months between randomization and the 6 month assessment (collectively, these 7 risks are the "On Meds Risks") include:

• Angina (chest pain, pressure or squeezing)
• Myocardial Infarction (improper blood flow to the heart)
• Atrial Fibrillation (abnormal heart rhythm)
• Heart Failure
• Pulmonary Edema (fluid accumulation in the air spaces of the lungs)
• Stroke (disturbance in the blood supply to the brain)
• Death

There are risks related to the blood tests required for the study, e.g., excessive bleeding, fainting or light-headedness, haematoma (bruising), infection, or the requirement of multiple punctures to locate a vein to draw the sample.

This research study involves exposure to a small amount of radiation. As part of everyday living, everyone is exposed to naturally occurring background radiation and receives a dose of about 3 millisieverts (mSv) each year. The effective dose from the renal denervation procedure is less than 5.5 mSv. The dose from this procedure is comparable to that received from many diagnostic medical x-ray and nuclear medicine procedures. At this dose level, no harmful effects of radiation have been demonstrated, as any effect is too small to measure.

There are risks of having magnetic resonance angiography (MRA) imaging done. These risks include: certain medication patches can cause a skin burn; you may feel claustrophobic when having the test, in rare cases an allergic reaction to the contrast solution can occur (if the contrast solution is used). Implanted medical devices that contain metal may cause problems during an MRA exam. There is a risk of damage to your kidneys from the contrast solution that may be used.

There are risks of undergoing computerized tomography (CT) scan. These include: medication patches that can cause a skin burn and allergic reaction to the contrast material (if used) and exposure to radiation.

Pregnancy

There is a possibility of risks to an unborn child. These risks are unknown. Women of childbearing potential will be given a blood or urine test to confirm that you are not pregnant prior to the cath lab procedure. Women of childbearing potential are advised to use contraceptive methods or abstain from sexual intercourse during the course of this study to avoid becoming pregnant. If you become pregnant you should advise your study doctor immediately. He/she will advise you on further medical attention should this be necessary.

The study may involve unknown or unforeseen side effects or complications other than those mentioned above.

If any complications occur, they may lead to repeat or prolonged hospitalization, repeat procedures, emergency surgery, other emergency procedures, or, in rare cases, death.

Although there are risks associated with participation, there will be a panel of doctors independent of the study that will monitor the safety of the study. They will be overseeing your safety and the safety of all study participants. For this reason, you should report any and all problems that you are having to the research staff. If you have any distress associated with participation in the study, you have the right to suspend or end your participation and your decision to forego enrolment will not adversely affect your medical care.