The Whys and Wherefore’s of White-Coat Hypertension

Yesterday was Mother’s Day for our readers who live in the US.  I do, but my mother doesn’t, so rather than treat her to lunch or chocolate, I’m dedicating this blog to her instead.

Let me start by saying that hypertension runs in our family.  My grandmother and her mother before her had it, my mother has it and even though I was an ultra-fit marathon runner at the time, I also developed high blood pressure around the time I turned 40.

But that’s where the family trait ends. We manage our disease very differently.  I take my meds, try to eat healthily, avoid stress and exercise whenever I can. I also avoid taking my blood pressure.  If I don’t know it’s high, it’s one less thing I have to worry about!  My mom, on the other hand is a much more compliant patient and goes for regular check-ups.

The problem with that, is she worries so much about having her blood pressure taken that it’s always high when she sees her doctor.  She can’t explain why she worries about this, she knows it’s not rational, but still she worries.  And she’s not alone.

For many patients, blood pressure measurements taken in a physician’s office may not correctly characterize their typical blood pressure. Up to 25% of patients evaluated by their doctors, have blood pressure measurements higher than their typical levels. This phenomena is known as white-coat hypertension and is thought to result from anxiety related to examination by a health care professional.

So I was really interested to read a new study from the UK where, incidentally, my mom lives.  It showed that by swapping a doctor for a nurse you can eradicate white-coat hypertension.

The meta-analysis of 14 studies found that mean blood pressures measured by nurses were 8.5/4.2mmHg lower than readings from doctors. When studies with a high risk of bias were removed from the analysis, the gap was reduced but remained, with a mean difference of 4.8mmHg in systolic blood pressure (the top number) and 1.5mmHg for diastolic (the bottom number).

The study concluded that blood pressure measurements taken by primary care doctors might be ‘unreliable for clinical decisions’, and that all measurements should be delegated to nurses.

Study leader Dr Chris Clark, clinical academic fellow at the Peninsula Medical School and a GP in Witheridge, Devon, said: “The difference could affect treatment decisions, especially when the measurement is marginal, between one course of treatment and another.”

Such a recommendation also has wide-ranging implications for how medical practices organize their services.  Researchers told the European Society of Hypertension Congress that the findings meant practices should move to nurse-only or home blood pressure monitoring.

The rationale for the different blood pressure values obtained by doctors and nurses?  The researchers speculate that nurses are better at relaxing patients.

Would you be more relaxed seeing a nurse rather than a doctor?  My mom says yes!

Simple, Fast, and Beautiful

Take a good look at the image to the left.  Could it be the latest high tech cardio machine from a swanky new-age gym, a computerized gold club that provides instant feedback on your swing or perhaps a revolutionary whole-house Bluetooth speaker system?

No, no and no!

What you are looking at, ladies and gentlemen, is a revolutionary new device for the treatment of high blood pressure.  Yes, that’s right. Not monitoring, but treatment.

The Vessix Vascular V2 Renal Denervation System™  is the result of a collaboration between two California based companies –  Vessix Vascular, Inc., a pre-revenue stage medical technology company, and product innovation consultancy Karten Design.

This new technology has the potential to help the 68 million (one in three) adults in the United States who suffer from hypertension — a condition that is more common than cancer, diabetes, and coronary artery disease combined.

Hypertension is a major risk factor for heart disease, stroke, congestive heart failure, and kidney disease and was listed as a primary or contributing cause of death for more than 347,000 Americans in 2008.

In 2010, high blood pressure cost the United States $93.5 billion in health care services, medications, and missed days of work

Today, anti-hypertensive drugs are the primary treatment for hypertension. But despite the widespread use of drugs, only about half of hypertensive patients around the world are well controlled, even when multiple medications are taken at optimal dosages.

This new device could potentially change all that.

In as little as 30 seconds per artery, the Vessix V2 System performs a one-time minimally invasive catheter-based percutaneous procedure that has been shown to significantly reduce blood pressure.
Using a short blast of radiofrequency (RF) energy to disable the sympathetic nerves surrounding the arteries leading to the kidneys, in a procedure called renal denervation.

TV’s  Dr. Mehmet Oz has called  this treatment “a profound game changer.”

Hyperactivity of the renal nerves leads to uncontrolled high blood pressure, also called resistant hypertension. According to the American Heart Association, a 5 mm Hg reduction in systolic blood pressure results in a 14% decrease in stroke, a 9% decrease in heart disease, and a 7% decrease in overall mortality. In clinical studies, renal denervation has shown to reduce systolic blood pressure by as much as 20%.

Vessix’s patented V2 Catheter delivers precise temperature-controlled energy to both renal arteries in 60 seconds, while the only other competitively marketed Renal Denervation system takes 50-60 minutes. The rapidity of the V2’s treatment promises to reduce patient discomfort as well as exposure to radiation for both the patient and the interventional cardiologist performing the procedure.

I wanted a design that immediately communicates that there’s something new and exciting going on — even before I explain how the product works,” said Vessix CEO Raymond Cohen. “The goal was to have the product look faster, sexier, and more advanced than any other piece of equipment found in the hospital.”

To ensure the system’s design supports the physician’s natural workflow in the catherization lab, Karten Design worked with Vessix during the early phases of product definition, visiting hospital cath labs and interviewing doctors to determine the system’s ideal usage. Karten Design researchers and designers learned about the human factors surrounding a catheter-based procedure, including visibility, access, and sterility.

Vessix began a 64-patient human clinical in February in Europe. The first patient treated was 39 years old with pre-treatment blood pressure readings of 174/114 despite taking four anti-hypertensive medications. The second patient was 44 years old with a blood pressure of 168/106 despite taking six anti-hypertensive medications. The 10 center study will follow patients for 24 months following their renal denervation procedure.

Although the system has already received a CE Mark approval for the treatment of hypertension, it is not yet available in the US.

Assuming all goes well with the clinical studies, we look forward to the day it is.