TORONTO — Luis Martins, a 57-year-old clerk at Bombardier, was discharged from hospital on Wednesday — the day after undergoing a 35-minute operation that immediately reduced his blood pressure from a life-threatening 210 over 125 to a healthy 130 over 70.
“I’m overwhelmed,” said Martin, moments before leaving the Peter Munk Cardiac Centre with his wife, Fatima. He was still feeling a little weak but good to go home.
“I’ve lived for many years with high blood pressure,” he says. Diet, exercise and even a brush with holistic medicine didn’t help.
Since he was diagnosed 10 years ago, Martins has relied on a steady stream of antihypertension drugs. He rattles them off — “Tiazac, Diovan, Hydrochlorothiazide, Spiroton, Loniten and Monocor.” He was on all six — every day — with little or no improvement.
For as long as he can remember, Martins has felt perpetually weak.
“I felt like I could have had a stroke at any time. I felt like a time bomb,” he says. In fact, Martins has been rushed to hospitals on three occasions. “I was treated and sent home,” he says.
There are almost 250,000 Canadians with high blood pressure who do not respond adequately to conventional drug therapies. As a result they face an especially high risk of heart attack and stroke.
But this week doctors at the Peter Munk Cardiac Centre in Toronto General Hospital performed surgery they hope will decrease a patient’s systolic blood pressure within a six-month period. The procedure is called renal denervation.
Martins is Canada’s first patient to undergo the experimental procedure.
Though the procedure is relatively simple, it was nonetheless performed by a multidisciplinary team that included cardiologist Dr. Douglas Ing, radiology specialist Dr. Dheeraj Rajan and vascular surgeon Dr. George Oreopoulos. The team had recently returned from Germany, where they trained for the procedure.
Renal denervation involves deactivating the nerves on the outside of the arteries that feed blood to the kidney. It has been known for more than 50 years that the kidney plays a defining role in determining blood pressure, and that when the nerves on the kidney’s arteries are hyperactive there is an increased possibility of high blood pressure.
Dr. Barry Rubin, medical director at the Peter Munk Cardiac Centre, says the procedure, pioneered in Melbourne, Australia, could help prevent many heart attacks and strokes in patients with poorly controlled hypertension. But he cautions the procedure is still in the experimental stage. If all goes well, however, renal denervation, “could very likely be performed as an outpatient procedure.”
For a variety of reasons, Martins is the ideal candidate.
He had a systolic blood pressure reading over 160 and had been on three or more blood pressure medications that were not effective.
Though Martins did not give his permission to be transfused with blood, because he is a Jehovah’s Witness, the treating physicians knew it was extremely unlikely that a transfusion would be needed.
The procedure begins with a two-millimetre puncture in the patient’s groin.
A wire is navigated through a catheter to the abdominal aorta and into the arteries that lead to the kidney. Through a process of “ablation” or controlled destruction, some of the “hyperactive” nerves that run on the outside of the blood vessels are destroyed — heated and inactivated with radio frequency energy.
Hyperactive nerves that lead into the kidney are just one contributor to hypertension, Rubin explains.
He estimates the procedure has the potential to save the health-care system “countless millions of dollars by minimizing the need for antihypertension drugs that patients have to take often for the rest of their lives, to say nothing of the millions more in savings from not having to treat heart attacks and strokes that don’t happen.”
The Peter Munk Cardiac Centre is the first centre in Canada to receive approval from Health Canada to perform renal denervation procedures.
As Health Canada’s website explains, such approval is only given for “patients with serious or life-threatening conditions on a compassionate or emergency basis when conventional therapies have failed, are unsuitable or are unavailable.”
“While it is very important to talk about potential benefits, it is also important to talk about the potential risks,” says Rubin, adding the long-term impact of the procedure has yet to be determined.
Over time, Rubin wants to know if the biochemistry of the kidney will change as a result of the procedure.
While trials have been conducted in various countries around the world, the procedure is currently approved only in the European Union and Australia.
Rubin says doctors will treat more patients over the next few months to better understand the safety and efficacy of the procedure.