The Management of Patients With Hypertension, Pt. 1

In this podcast episode, Dr Harrison and Paul Shiu, DO, discuss hypertension, including diet recommendations, how hypertension develops, and references to guidelines from The Journal of Nuclear Cardiology, The American College of Cardiology, and The American Heart Association on the evaluation and management of patients with hypertension. 

For more hypertension content, visit the disease state hub.

For part 2 of this 3-part podcast, click here.

Anil Harrison, MD, is the Program Director and Chair of the Internal Medicine Residency Program at the University of Central Florida and HCA Florida West Hospital (Pensacola, FL). Dr Harrison is board certified in India and the United States.

Paul Shiu, DO, is a second-year internal medicine resident at St Joseph's Medical Center (Stockton, CA).

TRANSCRIPTION:

Speaker 1:

Hello everyone, and welcome to Multidisciplinary Dialogue: Clinical Rounds and Case Reviews with your host Dr Anil Harrison, who is the program director and chair of the Internal Medicine Residency Program at the University of Central Florida and HCA Florida West Hospital in Pensacola, Florida. Today, we'll discuss the evaluation and treatment of patients with hypertension. The views of the speakers are their own and do not reflect the views of their respective institutions or the views of Consultant360.

Paul Shiu, DO:

Good morning, everyone. Welcome back for another Dr Harrison's podcast. My name is Dr Shiu. I'm a PGY2 in internal medicine learning alongside you all. I figured that today will be a good time to talk about hypertension. Some foundational stuff, right? Dr Harrison, how are you doing this morning?

Anil Harrison, MD:

Good morning, Paul. I'm doing well, and I agree with you. Let's talk about hypertension. Paul, in the old days, they used to say, "well, you shouldn't bottle up your emotions because that can cause high blood pressure." And I often wondered what happened to those who didn't or who wanted to vent. Of course, their blood pressure might have gotten better, but I often wonder if that was appropriate, the way they vented out, blow their steam, let's put it that way.

Paul Shiu, DO:

Oh yeah. Pop the top.

Anil Harrison, MD:

Right.

Paul Shiu, DO:

So what is the history? Why does salt get such a bad rap? I remember when I was in elementary school, salt had many uses. Before refrigeration, it was used to preserve meats. Would you give us a little bit of history as to why salt has been linked to hypertension and why it's been much maligned?

Anil Harrison, MD:

Sure. Absolutely. So about 5,000 years ago, folks hardly ate any salt. The diet consisted mostly of meat and fruit. Over the years, salt was introduced into the diet and salt became a marker for a country's socioeconomic status. People looked out at the sea divinely and remarked on the beautiful creatures that existed in the sea, and they thought it was because of salt.

While some believed salt kept the devil away, others felt it was godly to keep salt in their homes. The Romans believed salt would be the first thing to arrive on the table and the last thing to leave because it showed good hospitality. While trying to preserve their meat, salt was applied. Salt kept worms off carcasses, and so salt was used as medicine to help clear worms out of the system.

Salt was seen as a good preservative. And therefore, it continues to be used in mostly canned foods and other processed foods. Believe it or not, it was in the late 1800s, people figured that salt was causing problems, and experiments conducted on animals revealed salt as a cause for high blood pressure along with kidney issues. Interestingly, the Bedouins and the Alaskans stayed away from salt.

So, while managing hypertension, there was a lot of resistance from physicians, including well-known cardiologists, about cutting back on salt. When to begin anti-hypertensives was also a big question until the 1950's unless there was apparent end-organ damage, including left ventricle hypertrophy. Folks dithered from initiating anti-hypertensives. And anti-hypertensives such as beta blockers and the non-dihydropyridine antihypertensives were used as first-line therapies with other medications, such as clonidine, minoxidil, hydralazine, and diuretics. Folks with hard-to-treat hypertension were getting sympathectomies and adrenalectomies.

So that, I would say, is the history of hypertension, but I think it was in the 1980s when Captopril, the first ACE inhibitor, came out.

Paul Shiu, DO:

So am I right in understanding that the recommendation for salt now is less than 2000 milligrams per day, which is about equivalent to about half a teaspoon?

Anil Harrison, MD:

You're absolutely correct, Paul. Yes.

Paul Shiu, DO:

And then all this talk about salt, it must be very important because it affects our blood pressure. What exactly is the prevalence of hypertension?

Anil Harrison, MD:

Well, the prevalence of hypertension ranges from 30% to 60%, and it gets higher as one advances in age. The prevalence of hypertension varies based on the designated cut point, and it increases from 32% to 46% when the cutoff is changed from a blood pressure of greater than 140/90 to a blood pressure of greater than 130/80 millimeters of mercury.

Paul Shiu, DO:

Wow. So we're basically increasing the capture by lowering the threshold. So more people meet the criteria for hypertension then?

Anil Harrison, MD:

Absolutely.

Paul Shiu, DO:

Okay. And it's good to get a handle on things before the deleterious effects of having uncontrolled hypertension take hold. Right?

Anil Harrison, MD:

Very true.

Paul Shiu, DO:

Okay. Now that we know salt is linked to hypertension and we know why hypertension is so bad, how does one calculate their salt intake in the food that they consume?

Anil Harrison, MD:

So, in most packaging nowadays, the content of sodium is mentioned in the food, such as one gram of sodium per hundred grams of food. Now in salt, 40% is sodium and 60% is chloride, therefore one gram of salt equates to about 2.5 grams of salt per one hundred grams of food. So if the package has 250 grams of food, the total amount of salt would be 2.5 times 2.5, which equals six grams of salt.

Paul Shiu, DO:

Six grams of salt? That sounds like a lot. In fact, that sounds like it equals three days worth based on current recommendations, right? Less than 2,000 per day.

Anil Harrison, MD:

You're absolutely correct, Paul. So one can of food could actually have three days worth of salt in as a requirement.

Paul Shiu, DO:

Well, folks, I hope it was worth it. I know whenever I finish a bag of potato chips, I always tell myself it's worth it. Then the next day when my feet start swelling...

Anil Harrison, MD:

Yeah. You're absolutely right.

Paul Shiu, DO:

...instant regret. So moving forward, what defines hypertension? Why and how does hypertension develop?

Anil Harrison, MD:

Sure. So, there are various organizations. For example, the JNC has anything over 140/90 defined as hypertension. However, the ACC and the American Heart Association define hypertension as readings that are greater than 130/80 millimeters of mercury. So the diagnosis of hypertension, which is greater than 130/80 millimeters of mercury, should be based on an average of two or more elevated systolic and or diastolic blood pressure measurements obtained on two or more occasions.

So with systolic blood pressure ranging between 132-139 millimeters of mercury and diastolic blood pressure ranging between 80 to 89 millimeters of mercury is categorized as stage one hypertension. While systolic blood pressures 140 to 149 and diastolic blood pressures 90 to 99 millimeters are classified as stage two hypertension. So as mentioned, these relate to blood pressure readings taken at least on two occasions and at home, not at a physician's office.

So while 90% of hypertension is classified as having a primary etiology, it's only 10% that have a secondary reason for high blood pressure. With primary hypertension, genetic variants could include abnormal kidney sodium handling, increased activity of the renin-angiotensin system, and of course, an elevated sympathetic tone.

Paul Shiu, DO:

So, we briefly touched upon, and you even emphasized, that these measurements are taken at home, right?

Anil Harrison, MD:

Mm-hmm.

Paul Shiu, DO:

At least two occasions and at home. So for people who are taking their blood pressure at home, what is the correct way of measuring blood pressure?

Anil Harrison, MD:

Well, Paul, the recommendations are that the cuff size should be chosen very wisely to ensure that the bladder of the cuff encircles 80% of the upper arm. Because using a cuff that is too small will result in an artificially elevated reading, and using a cuff that is too large will result in an artificially lower reading. At least two measurements should be taken and averaged, and the two readings should be about a couple of minutes apart. Of course, one should avoid smoking, avoid caffeinated beverages, or exercise within half an hour before a blood pressure measurement.

A properly calibrated and validated instrument should be employed. Blood pressure should actually be measured in both arms during the first visit. And the arm with a higher value should be used to measure blood pressure during subsequent visits. The patients should be seated. They shouldn't be talking, they should be in a chair for at least five minutes with the back supported, feet on the floor, legs uncrossed, and the arm bared and supported on a flat surface at the level of the heart or the right atrium. And, at least two measurements should be taken and averaged two minutes apart.

The process should be repeated if the initial measurements differ by more than five millimeters of mercury.

Paul Shiu, DO:

Thank you for going over the correct procedure for measuring blood pressure manually. For those who have automated blood pressure cuffs, what are your thoughts, and how do automated devices compare versus the auscultatory method?

Anil Harrison, MD:

Automated devices have been shown to be closer to the awake cutoff office blood pressure levels measured with the ambulatory blood pressure monitoring and may have a stronger association with subclinical cardiovascular disease.

Ambulatory blood pressure monitoring using an electronic blood pressure measuring device is the gold standard for assessment of blood pressure out of the office and is a better predictor of cardiovascular outcomes, including left ventricular hypertrophy, cardiac death, when compared with office-based measurements. The device can be worn continuously for 24 hours and one can program it so that blood pressure is taken either every 15 minutes or every hour.

And normal blood pressure by the ambulatory blood pressure monitor, including a 24-hour average, should be less than 115 by 75 millimeters of mercury. And the daytime average should be less than 120/80, and nighttime blood pressure should be less than 100/65 millimeters of mercury.

Paul Shiu, DO:

So this automated device sounds incredibly versatile. It seems to aproach the accuracy of even in-office blood pressure readings. Right? And it has the added advantage of monitoring at predefined intervals, as you illustrated. So every 15 or up to 60 minutes. So in that case, the next question should be, what are some instances that you would recommend using a 24-hour device then?

Anil Harrison, MD:

Yeah. Some of the indications would be when you suspect white coat hypertension, which means that the blood pressure's higher when the patient comes to a physician's office. Also, with suspected masked hypertension, which means the blood pressure measures lower in a physician's office, but the patient tells you, "well, when I check my blood pressure at home, it's much higher."

It would also be useful for things like suspected episodic hypertension and also with apparently treatment-resistant hypertension. So you've got a patient on three anti-hypertensives already and you're kind of thinking about the fourth anti-hypertensive, so that would be another indication for an ambulatory blood pressure monitor.

And of course hypertensive symptoms with anti-hypertensive medication. The patient complains of lightheadedness and you've had one or two readings, so this would be a good thing to evaluate. Is the person's blood pressure actually dropping on the antihypertensive?

So those are some of the reasons that you would actually use the gold standard, which is ambulatory blood pressure monitoring. Now another reason would be possibly non-dipping. Now, what does non-dipping mean? Normally blood pressure should dip by at least 10% or more at night. So if you have nighttime blood pressures that are not dipping, that would be another indication for getting an ambulatory blood pressure monitor on a patient.

So these are some of the reasons, and of course, to ensure the most accurate blood pressure measurements at home, the upper arm cuffs are preferred over the newer devices that measure blood pressures in the wrist or in the finger. So the more peripheral you go, the systolic blood pressure would be higher and the diastolic blood pressure lower. So that is why I don't recommend my patients monitor their blood pressures using cuffs that go over a finger or the wrist.

Paul Shiu, DO:

And that's because it gives you a falsely elevated reading, the more distal you go to measure your blood pressure. You run the possibility of overtreatment.

Anil Harrison, MD:

Absolutely.

Paul Shiu, DO:

Okay.

Anil Harrison, MD:

Absolutely.

Paul Shiu, DO:

So with that being said, are there any guidelines to monitor blood pressure among adults?

Anil Harrison, MD:

Yes, absolutely. So adults aged 18 to 39 with a blood pressure less than 130/80-85 millimeters and without cardiovascular risk factors should be re-screened every three to five years. And those who are 40 years and older and at increased risk for hypertension. For example, those who have blood pressures ranging from 130 to 139 systolic or 85 to 89 diastolic, and who are overweight or who are Black, should be screened annually.

And the ACC and the American Heart Association recommend that adults with elevated blood pressures, 120 to 129/less than 80 millimeters of mercury, or stage one hypertension, which is 130 to 139 systolic and 80 to 89 diastolic, who are not yet on therapy should have the blood pressure repeated within three to six months.

Paul Shiu, DO:

And the range of 120 to 129 over 80, that's the pre-hypertensive range.

Anil Harrison, MD:

Correct. Correct.

Paul Shiu, DO:

Okay.

Anil Harrison, MD:

Absolutely.

Paul Shiu, DO:

So then, could you shed some light on organ damage, morbidity, mortality, and what will one be looking for in a patient with hypertension?

Anil Harrison, MD:

Sure. So let's start off with the eyes. As vasoconstriction on an arteriolar narrowing, confirming arteriovenous nicking or copper wiring on fundoscopic examination, it signifies endothelial damage. And you could also see retinal hemorrhages called flame hemorrhages. It could also result in optic neuropathy, which may result from ischemia to the nerve fiber. Secondary to fibroid necrosis of vessels, which manifests as cotton wool spots or optic disc power.

And, of course, hypertensive emergencies can lead to papilledema resulting from leakage, ischemia, fibroid necrosis, and ischemia, medium to large blood vessels, such as you could get peripheral vascular disease, including aortic aneurysms. Just as half of the transient ischemic attacks, it can cause lacunar infarcts and other stroke subtypes.

Hypertension is also associated with vascular neurocognitive disorders, such as vascular dementias. Similarly, hypertensive nephrosclerosis and chronic kidney disease can also result from hypertension. Hypertension can also cause left ventricular hypertrophy and, of course, hypertensive emergencies may cause aortic aneurysm rupture or aortic wall dissection.

And similarly, it has serious manifestations such as a hemorrhagic stroke or a subarachnoid hemorrhage from cerebral aneurysm rupture. You could also get acute coronary syndrome, myocardial infarction, and both diastolic and systolic heart failure.

Hypertensive emergencies can also cause acute kidney injury with arteria proliferation, fibroid necrosis, and also features of thrombotic microangiopathy.

Paul Shiu, DO:

So this concludes the first part of our hypertensive series. Please tune back in for the second episode, where we will pick up exactly where we left off. Where we'll be covering how we will evaluate a patient who is newly diagnosed with hypertension. How's that sound, Dr. Harrison?

Anil Harrison, MD:

Sounds great, Paul. Thank you so much.

Paul Shiu, DO:

Thank you, Dr. Harrison. And thank you everyone for tuning in. Thank you.

Anil Harrison, MD:

Bye.

Speaker 1:

For more information on hypertension, visit the resource center at consultant360.com