Keeping blood pressure under control is essential: there is a new option for the most difficult cases

Nothing doctors prescribed controlled Michael Garrity’s dangerous hypertension, until some nerves were removed from his kidneys.

If that sounds strange, it’s because the kidneys help regulate blood pressure in part through signals from certain nerves. The new treatment disrupts overactive kidney nerves.

“My blood pressure was high, I was out of breath and I felt tired, but that doesn’t happen to me anymore,” explained Garrity, 62, who lives in Needham, Massachusetts. He continues to take medications, but at lower doses, and his blood pressure is normal for the first time in years. “I am delighted.”

About half of American adults suffer from hypertension, a significant risk of heart attack, stroke, kidney failure and even dementia. Many people don’t even realize they have hypertension until it has caused serious damage.

“Know your blood pressure, know the numbers,” emphasizes Dr. Randy Zusman, from Massachusetts General Hospital, who specializes in the most difficult cases to treat and who advises people who believe they are well to at least have an annual check-up. .

And only a portion of patients have their hypertension well controlled, which means that novel strategies are needed. The Food and Drug Administration (FDA) approved the “renal denervation” option a year ago, based on studies showing a modest benefit in patients whose blood pressure remains high despite taking multiple medications.

Now, after the American Heart Association found it promising, some hospitals, including Mass General Brigham, are cautiously offering it while they figure out who are good candidates and whether their insurance will cover a minimally invasive procedure that costs thousands of dollars.

What is high blood pressure?

There are two figures that describe blood pressure. The upper one, the “systolic” pressure, is the force that the blood exerts on the walls of the arteries as it leaves the heart. The lower number, “diastolic”, measures that same pressure but between heartbeats.

Normal is less than 120 out of 80. Blood pressure fluctuates naturally throughout the day, being higher when you are physically active or stressed. But when it stays high—always 130 over 80 or higher, according to the most recent guidelines—it hardens the arteries and makes the heart work harder.

How to measure blood pressure

You don’t need to go to the doctor. In pharmacies, and sometimes even in libraries, it can be measured, and home blood pressure monitors can also be used.

To avoid falsely high readings, the American Medical Association gives some advice: Sit calmly with your feet on the floor and legs not crossed. Place the cuff on your bare arm, not on clothing. Do not hang your arm, rest it on a table.

Drugs are not the only way to treat hypertension

The first step is to change the lifestyle, especially in healthy people. The guidelines recommend losing weight, exercising, eating more fruits and vegetables, limiting salt and alcohol, and taking steps to manage stress.

Medication is essential when hypertension reaches 140 above 90. The average patient needs two or three drugs, sometimes more, along with a healthier life, Zusman said.

But the hypertension that Garrity has struggled with since he was 20 is resistant to treatment. Despite taking four to six drugs, following a strict diet, and exercising, his blood pressure regularly reached 150 out of 100, or even higher.

What is renal denervation?

Doctors thread a small catheter, or tube, through the blood vessels to the kidneys, then deliver pulses of ultrasound or radiofrequency energy. Those pulses pass through the renal arteries to selectively target surrounding nerves, said Dr. Joseph Garasic, an interventional cardiologist at Mass General who performed Garrity’s procedure. The intervention lasts approximately one hour.

Although it is already used in other countries, a key American trial of renal denervation failed about a decade ago, prompting changes before researchers tried it again. In November 2023, the FDA approved two catheter systems, from Recor Medical and Medtronic.

It is not a cure, and some patients do not benefit from it. But according to Garasic, several studies show an average decrease in blood pressure of between 8 and 10 points, a modest but important improvement. Some, like Garrity, see a greater decline, enough to gradually reduce the medication.

The FDA considered the procedure safe in carefully selected patients: it was not tested on kidney patients or patients with narrow arteries, for example. Additionally, the studies have only lasted a few years, which is not long enough to know whether the nerves could regenerate over time.

American Heart Association guidelines urge potential patients and experienced doctors to have “thoughtful, informed conversations” to decide who is a good candidate.