It's a major public health issue worldwide. High blood pressure afflicts millions of people and contributes to heart disease, stroke, kidney disease and death. Some patients' blood pressure can be regulated with drugs, but for others, perhaps two-thirds of all patients, medication does not work.
"These people who are coming to us have tried everything and they're still at very high risk for stroke, heart attack, kidney failure. So for them this has been a process that they have been working on for, often, decades," said Dr. Harry Dauerman, a cardiologist at Fletcher Allen Health Care in Burlington.
Dauerman is referring to the patients who are now enrolling in a new clinical trial at Vermont's largest hospital. It's called renal denervation and it's aimed at those with a systolic pressure of 160 or higher who have been on three or more medications without success. Here's how it works: Doctors insert a catheter into the femoral artery at the top of the leg, similar to a cardiac catheterization. But instead of heading to the heart, they head to both kidneys through the renal arteries.
"So the procedure is to go in with a catheter like I showed you before and engage that kidney artery like we always do, but now I use this specialized catheter that shapes itself and has an energy source. And I change the shape of it so it hits the kidney artery in four different places and I try to scar the nerves in four spots to block the impulses," Dauerman explained.
If they block those impulses being translated from the brain and the spine, doctors believe blood pressure will drop significantly. In two European studies where renal denervation is now approved and used regularly, patients saw an average drop of 40 milligrams of mercury. And with those kind of results, doctors here say the implications are huge-- a potential breakthrough treatment that could play a significant role in reducing mortality and health care costs.
"This is going to open a door to a whole new therapy for patients with hypertension," said Dr. Richard Solomon, a nephrologist at Fletcher Allen Health Care. "It's an open door also to patients who have heart failure. So I think the next direction that this is going to go is to take patients who have heart failure, which is in part generated by an interaction between the heart not pumping well and the kidney holding onto too much salt. This will prevent the kidney from holding on to too much salt."
Fletcher Allen is now enrolling patients in the six-month study. Half will get the procedure; the other half a placebo. But in six months when the results are revealed, those who didn't get it the first time, can have it a second time. And for patients with uncontrolled high blood pressure that's a risk most are willing to take.
Fletcher Allen is one of just three sites between Ohio and Massachusetts with patients currently enrolled in the study. Ninety sites and about 530 patients will eventually participate nationwide.
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