Previously, I wrote a detailed post on concerns that have been raised about certain blood pressure medications potentially increasing the risk of contracting SARS-CoV-2 or increasing the likelihood of death and serious disease related to the virus.
Millions of patients worldwide with heart failure and hypertension are taking drugs that inhibit pathways in the renal angiotensin aldosterone system termed angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs.)
Lisinopril and ramipril are common ACE inhibitors whereas valsartan, losartan, and irbesartan are common ARBs.
Speculation that these drugs might be contributing to mortality associated with COVID-19 was initiated by a “Rapid Response” published online March 3 by the British Medical Journal in response to an editorial on “preventing a COVID-19 pandemic.” and “Correspondence” to the Lancet published March 7.
Since then I’ve been following this topic closely but nothing has emerged from any new data or new expert analysis to suggest that patients should stop taking ACE inhibitors or ARBs.
It begins with this wonderful sentence: “The renin–angiotensin–aldosterone system (RAAS) is an elegant cascade of vasoactive peptides that orchestrate key processes in human physiology.”
The authors outline in detail the possible interactions between ACE2 receptors and SARS CoV-2.
For those not interested in the scientific details in the paper, the Cliff’s Notes version of this article is below. Basically, we have insufficient data to know if patients taking RAAS inhibitors are at higher or lower risk for serious SARS-CoV-2 infection.
KEY POINTS RELATED TO THE INTERPLAY BETWEEN COVID-19 AND THE RENIN–ANGIOTENSIN–ALDOSTERONE SYSTEM
• ACE2, an enzyme that physiologically counters RAAS activation, is the functional receptor to SARS-CoV-2, the virus responsible for the Covid-19 pandemic
• Select preclinical studies have suggested that RAAS inhibitors may increase ACE2 expression, raising concerns regarding their safety in patients with Covid-19
• Insufficient data are available to determine whether these observations readily translate to humans, and no studies have evaluated the effects of RAAS inhibitors in Covid-19
• Clinical trials are under way to test the safety and efficacy of RAAS modulators, including recombinant human ACE2 and the ARB losartan in Covid-19
• Abrupt withdrawal of RAAS inhibitors in high-risk patients, including those who have heart failure or have had myocardial infarction, may result in clinical instability and adverse health outcomes
• Until further data are available, we think that RAAS inhibitors should be continued in patients in otherwise stable condition who are at risk for, being evaluated for, or with Covid-19
So my recommendations (and more importantly the recommendations of every major society or organization which has weighted in on this topic) to patients remain the same: don’t stop your ACE inhibitor or ARB due to concerns about coronavirus.
Many of my patients with hypertension and/or cardiovascular disease are taking drugs termed angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs.)
Both types of drugs are mainstays in our treatment of hypertension and heart failure.
Lisinopril and ramipril are common ACE inhibitors whereas valsartan, losartan, and irbesartan are common ARBs.
Speculation that these drugs might be contributing to mortality associated with COVID-19 was initiated by a “Rapid Response” published online March 3 by the British Medical Journal in response to an editorial on “preventing a COVID-19 pandemic.” and “Correspondence” to the Lancet published March 7.
I’ve provided the paragraph in which the authors of the Rapid Response raise the question along with their rationale at the end of this post.
Primarily, however, in this post I want to reproduce comments from experts in this area which confirm my observation that the evidence is not sufficient to ask patients to stop these life-saving drugs.
Based on initial reports from China, and subsequent evidence that arterial hypertension may be associated with increased risk of mortality in hospitalized COVID-19 infected subjects, hypotheses have been put forward to suggest a potential adverse effects of angiotensin converting enzyme inhibitors (ACE-i) or Angiotensin Receptor Blockers (ARBs). It has been suggested, especially on social media sites, that these commonly used drugs may increase both the risk of infection and the severity of SARS-CoV2. The concern arises from the observation that, similar to the coronavirus causing SARS, the COVID-19 virus binds to a specific enzyme called ACE2 to infect cells, and ACE2 levels are increased following treatment with ACE-i and ARBs.
Because of the social media-related amplification, patients taking these drugs for their high blood pressure and their doctors have become increasingly concerned, and, in some cases, have stopped taking their ACE-I or ARB medications.
This speculation about the safety of ACE-i or ARB treatment in relation to COVID-19 does not have a sound scientific basis or evidence to support it. Indeed, there is evidence from studies in animals suggesting that these medications might be rather protective against serious lung complications in patients with COVID-19 infection, but to date there is no data in humans.
The Council on Hypertension strongly recommend that physicians and patients should continue treatment with their usual anti-hypertensive therapy because there is no clinical or scientific evidence to suggest that treatment with ACEi or ARBs should be discontinued because of the Covid-19 infection.
Prof Tim Chico, Professor of Cardiovascular Medicine and Honorary Consultant Cardiologist, University of Sheffield, said:
“This letter does not report the results of a study; it simply raises a possible question about whether a type of blood pressure and heart disease medication called ACE inhibitors might increase the chances of severe COVID19 infections. It does not give any evidence that confirms this, simply that it suggests such a relationship should be looked for.
“It is very important that this letter is not interpreted or reported as saying that ACE inhibitors are proven to worsen COVID19 disease. With more information we will begin to be able to understand whether the relationships between disease severity and existing disease and treatment.
“I strongly advise anyone on heart medications not to stop or change these without discussion with their doctor. If a patient stops their medication and worsens to the point of requiring admission to hospital at the same time as we are dealing with an increase in COVID19 cases, that would pose the patient a considerable risk and put further strain on the healthcare services.”
Prof Peter Sever, Professor of Clinical Pharmacology & Therapeutics, Imperial College London, said:
“There are some questions about whether certain drugs such as angiotensin converting enzyme inhibitors and angiotensin receptor blockers, commonly taken by patients with hypertension, heart failure and diabetes might increase susceptibility to corona virus infection. On the other hand these drugs could reduce the risk of serious lung disease following infection.
“At the present time we have no evidence as to whether either of these two possibilities are true.
“Patients could be put at risk by stopping these drugs, which are effective treatments for their current condition, without medical supervision, and until further evidence is available should be encouraged to continue their current treatment.”
Prof Hugh Montgomery, UCL Professor of Intensive Care Medicine, UCL, said:
“There is no proof yet that the use of ACE inhibitors worsen Coronovirus infection. There are theoretical reasons, in fact, why they might offer benefit in serious disease. I would not advocate people ceasing such medication until the evidence has been weighed and clear guidance issued.”
Dr Dipender Gill, Specialist Registrar in Clinical Pharmacology and Therapeutics at Imperial College Healthcare NHS Trust, and a Postdoctoral Researcher at Imperial College London, said:
“Evidence is currently lacking and it is too early to make robust conclusions on any link between use of angiotensin-converting enzyme (ACE) inhibitors and angiotensin II type-I receptor blockers with risk or severity of novel coronavirus disease 2019 (COVID-19) infection. Furthermore, the acute implications of stopping such medications in relation to effects on risk or severity of COVID-19 infection are not known. Patients should be advised to follow public health guidance rather than alter their medications without proper and informed consultation with their medical doctor.”
Let me repeat my main message: Do Not Stop Your Blood Pressure Medication Based On This Speculation.
I will keep monitoring this area and update you as information arises.
This article has been updated with additional information as of 3/30/20 with a newer post here.
N.B. It is not unreasonable to raise questions but before making substantial changes in treatment we need more data. Below, the BMJ Rapid Response
The question is, does there exist a connection between the use of these drugs and severe sequela of Covid-19? While the epidemiological association has not been investigated yet, several indicators underline the hypothesis of the link between ACE inhibitors and Covid-19:
On the one hand, it has been shown that the Covid-19 agent (also known as SARS-CoV-2), uses the SARS-COV receptor angiotensin converting enzyme (ACE) 2 for entry into target cells . The interface between ACE2 and the viral spike protein SARS-S has been elucidated and the efficiency of ACE2 usage was found to be a key determinant of SARS-CoV transmissibility .
On the other hand, it could be shown in animal experiments that both the ACE-inhibitor lisinopril and the angiotensin-receptor blocker losartan can significantly increase mRNA expression of cardiac ACE2 (5-fold and 3-fold, respectively) . Further, losartan also significantly increases cardiac ACE2 activity .
Is a link between these observations possible? Is the expression of ACE2 receptor in the virus targeted cells increased by the use of ACE-inhibitor/angiotensin-receptor blocker and is the patient therefore more at risk for a severe course? We need rapid epidemiological and preclinical studies to clarify this relationship. If this were the case, we might be able to reduce the risk of fatal Covid-19 courses in many patients by temporarily replacing these drugs.
The skeptical cardiologist has been testing out a unique and ingenious device which allows the simultaneous measurement of two key cardiovascular parameters: blood pressure and heart rhythm. Omron partnered with AliveCor to create the Complete which is the first combination blood pressure monitor and electrocardiogram monitor.
Given that Alivecor’s Kardia Mobile ECG device is capable of accurately identifying atrial fibrillation, the Complete offers patients the ability to monitor for the two biggest treatable risk factors for stroke: atrial fibrillation and hypertension.
I have evaluated the Complete in both office and home settings and find it to be easy to use and highly reliable.
The main component of Complete is an attractive unit that measures 9 by 4 by 5 inches, weighs a little over a pound and combines the blood pressure monitor and the AliveCor sensors. It ships with a wide-range D-ring BP cuff which fits 9 to 17-inch upper arms and runs on 4 AA batteries.
Recording Blood Pressure and ECG
You can easily record just blood pressure using the device right out of the box (after inserting the included 4 AA batteries.) However, the full capabilities of the device are realized in conjunction with Omron’s Connect US/CAN Smartphone app which can be downloaded for free. Once paired with the app, the device can record and transfer ECGs along with blood pressure measurements to the app and the cloud.
The process of recording a single-lead ECG on the Complete is nearly identical to the process when using the AliveCor Kardia mobile ECG device except that there are four sensors for Complete versus the two sensors on the Kardia device.
After opening the Omron app on your smartphone and pressing the “Record BP and EKG” button, you place the smartphone horizontally on the Complete cradle and put your hands on the sensors with thumbs on the tops sensors and 2-3 fingers on the lateral sensors as illustrated below.
Once the device senses a good signal the ECG recording will automatically begin and continue for 30 seconds. It’s important to stay very still and quiet during this time to optimize the recording quality.
Like the Kardia device if your fingers are too dry, electrical contact may be suboptimal. This can be fixed by wetting your fingers with an alcohol wipe, a spray from a sanitizer bottle or just water from the tap. See my discussion on this here.
I found the 4 sensors plus the stability of the device the sensors reside in made for a higher percentage of high-quality ECG recordings on the Complete versus the smaller Kardia device. Stability on the Kardia device is a particular issue for the elderly and we were able to consistently obtain good quality ECG recordings in my office on the frail and elderly with the Complete.
The PDF of the ECG can be emailed to yourself for storage or to your physician for his review. With a Premium plan upgrade, you can store the ECGS online or utilize KardiaPro which shares your BP and ECG data through the cloud with your physician.
Blood Pressure Plus ECG
You can choose to record BP and ECG separately or at the same time. To record both, place the BP cuff on your upper arm, push the start/stop button and then put your fingers on the ECG sensors. While the ECG is recording, the BP cuff inflates and obtains the BP measurement.
As always when taking BP it is important to make sure the cuff is at the level of the heart.
Using KardiaPro Online Dashboard With Complete
Many of my patients have both atrial fibrillation and hypertension. For them, the KardiaPro dashboard provides a unique online monitoring system that allows me to view both their blood pressure recordings and their ECG recordings in one spot.
Omron’s Complete now simplifies and consolidates the process of recording BP and ECG for such patients. A typical KardiaPro report from one of my combined AF and hypertensive patients appears below.
Where Does Complete Fit In The Home Monitoring Universe?
I see Complete serving in two important areas.
The first is as a consolidated unit for patients with atrial fibrillation and hypertension. Complete provides an easy, quick, and stable method for these patients to home monitor their BPs and their rhythm.
The second area is in physician offices. The ability to record a high quality, medical-grade ECG simultaneously with blood pressure will improve the physician’s ability to screen for hypertension and rhythm abnormalities in an efficient manner.
N.B. Looking at the Omron website today I note that Complete is selling for $159.99, a 20% discount.
Today’s post comes from the Wally, the life coach of the skeptical cardiologist, who (ultimately) relates what happened when he agreed to do a blood pressure experiment in exchange for medical advice.
Blood Pressure Story 1
I used to work for a company that, for a short time, rewarded healthy employees with lower insurance premiums. They based your score on body-mass-index (BMI), cholesterol, and blood pressure (BP). At the time, I was riding a bike a lot so my BMI was acceptable. My cholesterol was also within range since I take a low dose of a statin. But, my blood pressure? I’ve been doing battle with my blood pressure since the 1980s. So, on the morning of the screening, I took precautions: no alcohol the night before and no coffee before the test. Let’s talk about coffee for a moment: I’m an engineer and we use coffee for fuel. Never hire an engineer who doesn’t drink coffee. In fact, here’s how I interview a new engineering candidate:
Me: “Do you like coffee?” Candidate: “Yes” Me: “How do you like it?” Candidate: “Black.” Me: “Congratulations, you have the job!”
Back to the morning of the screening: I had no coffee and I may have had low blood sugar. I got in my car and started backing out. It’s 6:30AM and dark outside – backing, backing, backing, CRUNCH. In spite of having a backup camera I still somehow managed to hit my daughter’s car. I’m sure that sent my BP up. Fortunately, I had calmed down enough to pass all of my tests by the time I got to the screening center 30 minutes later.
Blood Pressure Story 2
On another morning I had to go to the dentist – I always go early so that I don’t miss any work. So, with three cups of coffee in me I hit the road. Of course, I didn’t take traffic into consideration and I was 10 minutes late. The staff at the dentist’s office didn’t mind but I was a little anxious because 1) I hate to be late and 2) I was at the dentist’s office.
They have me sit in the adjustable padded chair and ask me the usual questions about changes in the meds I’m taking. While that’s going on, I’m trying to remember if this is the visit where they take X-rays or the visit where they use a needle to evaluate the pliability and travel of my gumline. Trust me, the gumline eval is not fun and as I start to think it’s going to happen, the hygienist puts a small integrated blood pressure cuff on my wrist. Really? You’re about to poke sharp things into my mouth and you’re measuring my BP? Of course, it’s terrible. They measure again: not so terrible. And on the 3rd measurement? Back to terrible.
Ever hear anybody say, “The dentist sure was fun today!” No, you haven’t. That sentence has never been spoken – unless the valve on the nitrous tank was leaking. This guy though, he liked to visit his dentist:
Blood Pressure Story 3
I had a semiannual physical coming up and I realized I better follow my doctor’s advice from my last visit and measure my BP first thing in the morning – before the coffee. Now, I have an old blood pressure cuff that I bought at a garage sale about 20 years ago and it still worked. But I started wondering how accurate it was given its age. So I went shopping on Amazon and decided to buy the same wrist cuff that they use at the demented dentist office. The morning after it came, I measured my BP and… well it wasn’t very good. So, I called my good friend The Skeptical Cardiologist and asked for his advice. And he graciously agreed to help – for a price. We made a deal: he would guide me on my journey to a lower BP. In exchange I would collect some data and provide an opinion on the different cuffs.
In other words: I volunteered to be the SC’s Lab Rat. At first I was proud that he was considering me to provide invaluable data. But, as time went on, I started thinking this might have been his revenge for a laboratory mishap that I caused when we were undergrads. Anyway, on to the experiment!
Your basic brachial BP cuff purchased at a garage sale.
OMRON 3 Series Wrist Blood Pressure Monitor
New. Can save data to your phone via bluetooth. Small.
First thing in the morning:
Take three measurements on the left wrist with the Omron
Take three measurements on the left arm with the LifeSource
Take three measurements on the right wrist with the Omron
Take three measurements on the right arm with the LifeSource
I’m a lousy scientist. I started off with good intentions but pretty soon, I started forgetting the evening measurements. And then, when I saw that there wasn’t too much deviation between the measurements on my left and right arms, I only made left arm measurements.
Here are the first two days of data:
The BP measured on my right side was lower in the morning and higher with the wrist cuff in the evening.
On the 2nd day, left and right were more consistent but the wrist cuff was higher in the evening. About this time, I was already getting annoyed with the wrist cuff and decided to return it. My reasons for this are detailed below.
I continued to measure my BP in the mornings using just the LifeSource cuff:
Other than the data from 1/5/20, there appears to be reasonably good correlation between the left and right arms.
Note the 12 day gap between the last two data sets. That’s because:
On the morning of January 8th, the LifeSource UA-767 blood pressure cuff crashed and burned on my kitchen table. The root cause of the failure was a small molded rubber doohickey that acted as an attachment point for the air system in the meter. I now had no means of measuring my BP. The experiment was over.
Review and Wrap Up
First of all this was not a very scientific experiment. By changing my meds I was able to get my BP down but I failed to collect all the data that the SC asked for. The reasons for this were 1) I returned the Omron wrist cuff early, 2) I kept forgetting to take my BP in the evening (it was a little crazy at my house over the holidays), and 3) the LifeSource died. But I had used both instruments long enough to form an opinion:
I had high hopes for the Omron wrist cuff – it was new, and it was small with none of the awkwardness of the more traditional brachial style cuff. But I quickly started finding flaws:
A wrist cuff has to be carefully positioned to get accurate measurements. While Omron says that the edge of the strap should be 1/2” away from the bottom of your palm, I had better luck just centering the strap over the vein where your radial pulse is measured. And besides, exactly where is the bottom of my palm? I could see where that would confuse some people.
I found that manipulating the strap on the wrist cuff with one hand to be a little more difficult than the brachial cuff. Now maybe if I had kept it longer I would have become more adept but right away I felt that this could also lead to some positioning errors.
To make accurate measurements with the Omron requires that you elevate your wrist to the same height as your heart. You can do this one of two ways: 1) physically hold up your wrist for the duration of the measurement or 2) prop it up with a pillow. This step is not required with an arm cuff because once applied it’s already positioned at roughly the same height as your heart.
Home blood pressure monitors have small air pumps in them to pressurize the cuff – that’s the buzzing sound you hear when you press the Start button. Since the enclosure for the Omron monitor is smaller than the LifeSource device, it has to use a smaller air pump. And a smaller air pump needs more time to pressurize the cuff. So you have to sit there and hold up your wrist while waiting for the cuff to pressurize – I found this a little tiring.
On the plus side the Omron did come with a small plastic case and didn’t take up too much space. And it had Bluetooth which allowed me to save my measurements on my phone using their app.
The LifeSource was a boring old fashioned BP Meter that got the job done – until it died. My only complaint about these devices is that they’re awkward to store. There’s the cuff, the base, and the rubber tube connecting the two. Combined these things always get tangled up with other stuff.
The old fashioned arm cuff is the way to go based on my experience. Yes, they’re awkward but they are solid and less prone to error. Because of this, I replaced the LifeSource with an Omron arm cuff monitor. And for storage I also bought a small enclosure for it. And as for my BP, I was able to get it down in time for my doctor’s appointment.
When Wally is not creating laboratory mishaps or providing life coach consulting he dabbles in electrical engineering, tells mysteriously hilarious jokes, and runs a website called Pi-Plates.com.
We met our freshman year at Oklahoma University and Jerry claims my first words to him were “Are you ready for the country?”
The Omron HeartGuide (OHG) is a digital wristwatch that takes oscillometric measurements of blood pressure. Named to TIME Magazine’s Best Inventions of 2019 list, the promise of this device was succinctly summarized by an Omron executive: “Integrating a blood-pressure monitor into a sleek watch that also measures sleep and activity makes staying on top of cardiovascular health easy and provides a fuller picture of overall wellness.”
Previously on the skeptical cardiologist, I described my excitement at the HeartGuide’s ability to “serve as an accurate and unobtrusive daytime ambulatory blood pressure monitor.” After wearing the HeartGuide for a week and using it in a variety of situations to measure my blood pressure I had begun rethinking my usual recommendation against wrist blood pressure cuffs.
For me, the great attraction of the OHG was and still is the ability to measure your BP “anytime, anywhere.”
Despite my unabashed enthusiasm for the Heart Guide’s ability to provide facile daytime BP monitoring, certain limitations need to be recognized.
Herein is my more detailed, objective and pragmatic review of the device.
What Is In The Cube?
The OHG is available on the Omron website for $499 but upon checkout currently, Omron is providing a 10% discount along with free economy shipping.
The device is available in medium and large wrist sizes. I sized my wrist as a medium using the measuring tool on their website.
Proper wrist sizing is crucial for accurate BP measurement.
The OHG ships in a black cube.
Inside the cube you will discover:
1 Paper Sizing Guide
1 Instruction Manual
1 Quick Start Guide
1 Charging Clip
1 AC Adapter
1 Charging Cable
2 Replacement Cuff Sleeves
The OHG is large but stylish in appearance. It weighs 115 grams and the watch dial has a diameter of 1.9 inches.
I found it took about 2 hours to fully charge the battery and that the device remained charged for about 48 hours.
Preparing For Blood Pressure Measurement
For accurate BP measurement, it is important to follow very closely the directions Omron provides. The band should be positioned about 1 inch (2 fingers) below “the base of the hand.” The fit should be “snug.” Your index finger should not easily slide between the band the wrist.
The instructions ask you to sit in a chair for measurement and “position at heart level.” However, as I discussed in my previous post I found that I could make BP measurements under a variety of circumstances beyond chair sitting.
The OHG is fairly finicky about stability and positioning. The directions for positioning state “position HeartGuide at heart level with 2 inches space between wrist and chest.” To ensure accuracy “do not bend your wrist or look at the display during measurement.”
Here’s what Omron says about its “Heart Zone Indicator”:
Your monitor has a built-in heart zone indicator that is used as an aid in determining if your monitor is at the correct height and position. It has been designed to work with most people so that when your wrist is at the correct position relative to your heart, your monitor will vibrate once. If it does not vibrate, your monitor may not be at the correct height and position relative to your heart.
Due to differences in individual size and physique, this feature may not be helpful in all cases and you may wish to turn off this feature. If you feel the position of the wrist, according to the heart zone indicator’s guidance, does NOT match your heart level, please turn off this feature and follow your judgment.
It’s not clear to me how the OHG knows that it is at heart level. I experimented with various positions including lying on my back and standing with my wrist definitely at heart level. Sometimes the OHG agreed, others not.
It is clear, however, that it does not like significant movement. It would not make a measurement if I was walking at any speed or while exercising on an elliptical or stationary bicycle.
Measuring A Blood Pressure
Once positioned properly simply push the top button on the watch and put your wrist in the appropriate position. You will notice a vibration followed by an initial mild inflation of the cuff that lasts about 15 seconds followed by a pause of a few seconds then a full , tight inflation of the cuff.
The entire process takes over a minute and is significantly slower than the upper arm BP cuffs I have been using.
When completed, the cuff deflates and the systolic and diastolic blood pressure along with pulse rate are displayed.
Not infrequently after triggering the device I received an error message. Most commonly I encountered Errors 4 or 5 which indicates excessive movement or talking
Before I could recommend the OHG in particular or wrist BP cuff devices, in general, I needed to know how they compared to the gold standard brachial artery, upper arm BP cuff.
The lead author of this study is an MD, PhD working at the Jichi School of Medicine in Japan and his 3 co-authors all work for Omron Healthcare, Kyoto, Japan, which provided funding for the research so this skeptical cardiologist takes this information with a grain of salt.
The introduction to this paper points out that ambulatory blood pressure monitoring is important to help identify individuals who have higher blood pressure outside the clinic. Such individuals have masked hypertension, the opposite of white-coat hypertension.
The researchers concluded that both the large and medium wrist HeartGuide devices were accurate and fulfilled criteria set by the American National Standards Institute, Inc/Association for the Advancement of Medical Instrumentation/International Organization for Standardization.
Here are the Bland-Altman plots from that study
Note that although the average difference between the reference BP and the HeartGuide systolic BP is close to zero there is a significant variation from zero for individual measurements with some 20 mm Hg higher and some 20 mm Hg lower.
My experience confirms this significant individual variation. I took a number of simultaneous measurements using the HeartGuide on one wrist and a brachial BP cuff on the contralateral arm. I did this over multiple days under differing circumstances and with the devices on different arms.
I found that the HeartGuide systolic blood pressure was on average 10 mm Hg lower than the brachial BP when my blood pressure was high (>140 mm Hg). When my systolic BP was between 120 and 130 mm Hg the HeartGuide was 5 mm Hg lower than the brachial and when my blood pressure was less than 120 mm Hg the Heart Guide and brachial BPs were identical.
I made similar measurements on other volunteers and found some had consistently identical wrist and brachial SBP whereas others had consistently higher blood pressures by wrist compared to brachial techniques.
Because of this individual variation I highly recommend users calibrate the OHG (or any wrist-based BP cuff) versus a standard BP cuff over a series of days with multiple measurements to see how the two measurements compare. If you find a consistent over or underestimate then the device can be used with this known adjustment.
Comfort, Form, Fit
The OHG is big. and it is bulky. The fastening strap is made of thick rubber and underneath that is the inflatable microcuff which works like the larger cuffs designed for brachial/upper arm measurement.
I was always aware of something on my wrist when I was wearing it. The OHG cannot be accessed if you are wearing a coat or any garment with thickish sleeves. Getting most upper garments on and off while wearing the OHG is a chore.
In the picture below you get a feel for how the OHG interacts with long sleeve garments. My shirt sleeve would not slip over it. When I was wearing a coat or sweatshirt I could not access or view the OHG as its large size prevented pulling back the sleeve.
Some Other Things the OHG Does
The OHG measures steps and it tells time. Omron also indicates it can be used to measure sleep quality. Frankly, I did not test this feature because I felt I would not be able to sleep comfortably with the device on my wrist.
The OHG pairs via Bluetooth with the Omron smartphone app “Heart Advisor.” The app displays imported BP, pulse, activity and sleep data in various graphic formats.
Data can be exported from the Heart Advisor app by email in either an Excel or PDF file. This feature would allow the user to conveniently send recorded BPs to their physician.
The OHG sends an alert when you receive a text message or phone call but you can’t see the text message or answer the call.
Overall Pros and Cons
I am still a fan of the OHG despite the limitations I have indicated above.
I don’t see most people using the OHG as their every day smartwatch The inconvenience and discomfort factors for most will outweigh the benefits.
However, I do see a very beneficial role in wearing the OHG periodically for targeted purposes. For example, it could be worn to work once per week to determine how one’s blood pressure is reacting to stressful situations or to the gym to assess one’s blood pressure before and after a workout. At least one study suggests that BP obtained at work is superior to 24 hour or sleep BP in predicting end-organ damage (manifested by echocardiographic left ventricular hypertrophy) from hypertension
If Omron can develop a method for the device to automatically trigger during sleep and provide accurate nocturnal BP measurements this would be a huge advance in the management of hypertension.
N.B.Technical Specifications for the OHG
Model: BP8000-M Display: Transflective memory-in-pixel LCD Memory: Blood pressure measurement up to 100 times, Activity measurement up to 7 days, Sleep measurement up to 7 times, Event up to 100 items Transmission method: Bluetooth® low energy technology Power source: 1 Lithium ion polymer rechargeable battery, AC adapter Battery lifespan: Will last for approximately 500 cycles, 8 times/day measurements in normal temperatures of 77 °F (25 °C) when new battery fully charged Battery life: A typical user can expect to charge HeartGuide approximately 2-3 times per week, depending upon the frequency of use of HeartGuide’s features Weight: Approximately 4.1 oz (115 g) Dimensions: Diameter approximately 1.89” (48 mm), Case thickness approximately 0.55” (14 mm), Band width approximately 1.18” (30 mm) Measurable wrist circumference: Medium – 6.3” to 7.5” (160 to 190 mm), Large – 7.1” to 8.5” (180 to 215 mm)
Aaarggh! As the newly-minted wife of the skeptical cardiologist likes to say.
The media threw caution to the wind and went gaga over this study which proves nothing of the sorts of things described above.
They may have been egged on by the authors who were wildly overstating the implications of the study
“What we found in this study is that we’re able to reverse the processes of aging that occur in the [blood] vessels,” says study author Dr. Anish Bhuva, a British Heart Foundation Cardiology Fellow at Barts Heart Centre in the UK..
Allison Aubrey did manage to quote a sensible person in her report to counter the balderdash being thrown around by the study authors:
The heart health benefits documented in the study likely have much less to do with the one-time race event than they do with the fact that the training program got people in the habit of regular, moderately intense exercise, says exercise researcher Dr. Tim Church, an adjunct professor at the Pennington Biomedical Research Center. On average, the participants ran between 6 and 13 miles per week, during their training, so, not super long distances.”The training program was very practical and very doable,” says Church, who was not involved in the study, but who reviewed the training regimen and results for NPR. “It was a slow build up over six months,” Church says.
One thing I know for sure is aortic distensibility is highly dependent on systolic blood pressure and any changes that were seen in this study could simply have been related to lower systolic blood pressure.
The authors acknowledge this limitation along with about a million other limitations at the end of their paper. The limitations are legion and I’ve copied them at the end of this post. I’m quite surprised that JACC published it given those limitations and the absence of any important new findings.
Taking up exercise is really good for you but do not be fooled by these ridiculous headlines into thinking running one marathon has any special way to make you younger.
Take up exercise that you can sustain and that won’t leave you injured or frustrated.
This study was conducted in healthy individuals; therefore, our findings may not apply to patients with hypertension who have stiffer arteries that may be less modifiable (40). From these data, however, those with higher SBP at baseline appeared to derive greater benefit. This study was not designed to provide structured training, but rather to observe the effects of real-world preparation for a marathon, which randomized control trials cannot address. Nevertheless, information on the intensity, frequency, and type of exercise training would have been valuable to understand further the beneficial effects on aortic stiffness. The modest change in peak VO2 may be related to exercise training intensity or low adherence, which reflects the real world. Peak VO2 was performed semisupine to allow concurrent echocardiography, and this may also have reduced sensitivity to changes due to running or running efficiency. We assessed only marathon finishers—plausibly, nonfinishers could have had different vascular responsiveness. The causal link of exercise to measured changes is only inferred—marathon training may lead to other lifestyle modifications (dietary, other behavioral factors), or alterations in lipid profiles and glucose metabolism, although these have not been previously associated with changes in aortic stiffness (11). We did not examine the effect of exercise on peripheral arteries or endothelial dysfunction. Although individual participants served as internal controls, there may have been run-in bias for the initial BP measurement. This appears unlikely, as BP changes would not have been age-related nor correlated with the change in separate measures (e.g., aortic stiffness) with training. Estimated aortic ages are approximations and are based on the same dataset at baseline rather than independent observations. The exercise dose-response curve here is not sampled—only training for a first-time marathon with single timepoint assessment. This area warrants further study. We measured distensibility on modulus imaging acquired at 1.5-T rather than steady-state free precession imaging. The free-breathing sequence we used achieved good temporal resolution, but may be susceptible to through-plane motion. However, this and similar sequences correlate well with breath-held cine imaging, and show similar associations with aging (18). If error was introduced into distensibility measurements related to through-plane motion, the resultant noise would minimize the effect size related to exercise training, and therefore would be unlikely to account for our key findings. PP undergoes amplification from central to more peripheral locations, typically being ∼6 mm Hg higher in the descending thoracic than the ascending aorta (20). This PP amplification is not accounted for in our analysis, because it would have involved invasive measures of aortic pressure at each location. A sensitivity analysis suggested that the likely impact of this effect on the observed changes after training would be minimal; however, we cannot completely exclude the possibility that changes in PP amplification contribute to the observed differences. Diaphragmatic descending aortic distensibility data reported here were, however, higher than expected, although there is limited published data for comparison (41). Unlike Voges et al. (41), central rather than brachial PP was used, which would explain greater distensibility, and the use of 1.5-T phase-contrast modulus may accentuate image contrast differences between 3T gradient echo sequences.
In that post I stressed the importance of measuring at least once the “interarm BP difference” (IAD) and I promised to give a second post which would “give my recommendations on how to reliably measure IAD and ….tell the story of a 75 year old competitive ice hockey player with a totally blocked subclavian artery to his right arm.”
I saw that remarkable patient, Alan Gerrard, in follow up recently and the visit reminded me of my promise. After 25 years of playing competitive hockey he had finally decided to hang up his skates and retire from the sport he loves.
Here’s what I initially wrote:
The Ancient Hockey Player
The skeptical cardiologist started thinking about IAD because of Alan Gerrard, a most remarkable 77 year old who is still playing competitive ice hockey. Last year an errant hockey puck shattered his shin bone but after 6 months of recovery he is back on the ice, older by 11 years than his nearest competitor.
Alan has noted since his time in the military that the blood pressure in his right arm is significantly lower than that in the left. In fact, he would routinely ask that his BP be taken in the left arm to avoid being diagnosed with hypertension.
The pulse in his right wrist is much weaker than that in his left.
A few years ago, after identifying this IAD, I had him get an MRA of the arteries coming off his aorta and it blockage of the right subclavian artery which supplies blood to the right arm.
Since identifying this IAD we exclusively utilize the left arm BP to guide treatment of his hypertension.
At home he keeps a meticulous journal of his right and left arm BPs and brings them in for me to review at office visits.
In the first column he records his left arm BP
on arising. On April 1 it was 120/64. The IAD was 15 meaning his right arm BP was 105.
Interestingly, there is a marked variation in the IAD, as it ranges from+7 to minus 31 (averaging 10 mmHg)
The average systolic blood pressure in both the right and left arms was identical at 139.
Alan, also shares with me at our office visits a beautiful color-coded graph of his right and left arm BPs which are recorded daily without fail.
At our most recent visit he pointed out that when he was in Colorado at high altitude his blood pressure significantly increased (which, according to a recent European Society of Cardiology report is common.)
Providing Alan’s story was the easy part of my promise. Providing the best method for determining IAD turns out to be much more complicated and likely explains why I never wrote the follow-up post.
It also likely explains why 71% of patients in my poll have never had the IAD checked by a doctor (see below.)
A 2014 study found 8.6% of diabetics had an IAD >10 mm Hg. These patients were 3.5 times more likely to die from cardiovascular disease. An IAD>15 mm Hg conferred a nine-fold increased risk of cardiovascular mortality.
This is how IAD was assessed in this British study:
Carry out two pairs of simultaneous BP measurements:
Swap cuffs over (do not disconnect cuffs from BP machine) and obtain two further pairs of simultaneous readings
They utilized two automatic Omron BP devices. The authors recognized the difficulty of this technique in routine clinical practice:
Confirmation of an interarm difference requires a method of repeated simultaneous measurement, to avoid overestimation of prevalence This technique, however, may not be practical in routine clinical care. It adds time to the clinical assessment of subjects in primary care, and we have found it to be a barrier to recruitment in our previous study in diabetes. Initially, a sequentially measured pair of readings may be sufficient to rule subjects out of further assessment for an interarm difference, but this requires further evaluation.. Previous small studies that directly compared sequential and simultaneous measurement techniques have concluded that the reproducibility of an interarm difference measured by different techniques is poor (3 although we have found that repeated sequential measures can predict a systolic interarm difference ≥10 mmHg on repeated simultaneous measurement.
Dr. P’s Recommended Method for Measuring The IAD
Here’s what I will be asking my MAs to do to assess IAD:
Simultaneously measure BP with automatic cuff on one arm and manual cuff on the other. Switch arms and repeat measurements.
This should be done at least once on all patients with hypertension or diabetes.
For those wishing to test at home who only have one cuff I would suggest the following protocol:
Rest for 5 minutes in a chair. Check left arm BP. Switch cuff to right arm and measure twice. Switch cuff to left arm and measure. Perform this set of measurements one first thing in the morning and once after dinner. If a significant IAD difference (>10 mmg Hg) is noted on the averaged readings repeat the whole process two more times and if it persists report this to your doctor.
If you note a significant IAD always utilize the arm with the higher BP for measurement.
N.B. In 2017 I included a poll. Here are the results.
I’ve been evaluating a wearable wrist watch blood pressure monitor for the last week.
After a Twitter interaction with Omron stimulated by Dr. Wen Dombrowski, the Omron people loaned me one of their HeartGuide devices.
Omron’s website describes the device as follows:
Engineered to keep you informed, HeartGuide is a wearable blood pressure monitor in the innovative form of a wristwatch. In tandem with its companion app HeartAdvisor, HeartGuide delivers powerful new technology making tracking and managing your blood pressure easier than ever before. Proactively monitor your heart health by turning real-time heart data into heart knowledge and knowledge into action. With HeartGuide wherever you go, you’re in the know.
I and the AHA have not recommended wrist BP devices. My decision was based on my personal research in the 1990s on arterial waveforms and the influence of wave reflection. Studies have clearly shown a change in the arterial wave form as it proceeds from the ascending aorta to the periphery.
Therefore, the skeptical cardiologist was skeptical of the value of the HeartGuide
After wearing the HeartGuide for a week and using it in a variety of situations to measure my blood pressure I am rethinking my recommendation against wrist blood pressure cuffs.
I’ll give my full analysis of the device after more evaluation but what I’ve discovered is that it can serve as an accurate and unobtrusive daytime ambulatory blood pressure monitor.
Ambulatory blood pressure monitoring (ABPM) utilizes a portable BP monitor which includes a brachial BP cuff and a device that inflates the cuff every 20-30 minutes, makes a measurement and stores all the recordings for off-line review. Studies have shown ABPM is a better predictor of CV mortality than either clinic BP or home BP monitoring.
It has not been widely utilized in the US because it is poorly reimbursed.
The HeartGuide sits on my wrist and whenever I feel like it, wherever I am, I can quickly and simply make a recording of my BP.
With the HeartGuide I have made BP recordings in a variety of situations which I would never previously have considered.
For example, earlier this week I wore the HeartGuide to work. I measured my BP at home and it was 125/76. After dropping my gear off at my office I walked to the 6th floor of the hospital to see inpatients. This involved going down several flights of stairs, crossing to the hospital via a pedway and climbing several flights of stairs.
When I emerged on the 6th floor I stopped (because the Heart Guide does not like it if you are moving), triggered the Heart Guide and put my right hand over my heart (the Heart Guide likes you to put your hand on your heart). Within 90 seconds I knew my BP (it had increased to 143/81).
In order to do this unobtrusively I wandered into the patient waiting area and pretended to be watching NFL highlights on the TV. Nobody seemed to notice I was taking my BP!
Subsequently, I was paged to do a transesophageal echo/electrical cardioversion and went downstairs to our “heart station” where a room full of RNs, a sonographer, an anesthetist and a patient awaited me. While talking to the patient about the procedure I triggered the Heart Guide and made another BP recording. Nobody noticed!
The Heart Guide BPs are displayed on the watch face for a few seconds and can be sent via BlueTooth to the OmronAdvisor smartphone app.
The graph above shows my BP was high at 807 AM while I was talking to the patient and still up after the procedure.
One day I wore the HeartGuide to the gym and made BP measurements under a variety of conditions.
The HeartGuide will not activate while walking on the treadmill no matter how hard I try to keep my arm still. It does not like motion of any kind.
But the first reading on the left was immediately after running on the treadmill. I then performed an isometric leg press hold on a weight machine and was able to obtain a recording during this maneuver of 140/88. Shortly after the leg press I repeated the recording and it had dropped down to 104/69.
I have to say this is an abundance of BP information that is quite interesting and heretofore I had never been aware of. It opens up intriguing clinical possibilities.
I will have to spend more time analyzing the Heart Guide before writing my overall impression and recommendations but thus far I see it expanding our toolkit for understanding hypertension and personalizing cardiovacular medicine.
Try to imagine yourself standing like me outside a restaurant unobtrusively taking your blood pressure and ponder the possibilities!
Soon you may find that wherever you go, you’re in the know. But be aware of the possibility of being arrested for loitering while checking your BP.
If you’d like to read a detailed description of the HeartGuide check out this review while eagerly awaiting my more serious and more complete analysis.
Increasingly, the skeptical cardiologist has been recommending to patients that they take BP meds at bedtime as evidence has mounted that this does a better job of normalizing asleep blood pressure and minimizing daytime side effects.
Now a study published in European Heart Journal in October has demonstrated that routine ingestion of BP meds at bedtime as opposed to waking results in improved 24 hour BP control with enhanced decrease in asleep BP and increased sleep-time relative BP decline (known as BP dipping.)
More importantly, bedtime BP med ingestion in this randomized trial of over 19 thousand hypertensive Spaniards resulted in highly significant reductions in cardiovascular events including death, heart attack, heart failure and stroke over a 6 year median follow-up
The so-called Hygia Chronotherapy Trial was extremely well done and the results are powerful and should modify clinical practice immediately.
This figure demonstrates the dramatic and highly significant 45% reduction in all types of cardiovascular events measured. Note that stroke rate was halved!
Here are the Kaplan-Meier curves showing early and progressive separation of the treatment curves.
There was no difference side effects or compliance between the two groups.
The remarkable aspect of this intervention is that it costs nothing, introduces no new medications and has no increased side effects.
This study is practice-changing for me. We will be advising all hypertensive patients to take their once daily BP meds at bedtime.
h/t Reader Lee Sacry for bringing this study to my attention
I have found self-monitoring of patient’s BP to substantially enhance patient engagement in the process. Self-monitoring patients are more empowered to understand the lifestyle factors which influence their BP and make positive changes.
Blood pressures are amazingly dynamic and as patient’s gain understanding of what influences their BP they are going to be able to take control of it.
If high readings are obtained in the office I instruct patients to use an automatic BP cuff at home and make a measurement when they first get up and again 12 hours later. After two weeks they report the values to me (preferably through the electronic patient portal or by Kardia Pro.)
• Avoid smoking, caffeinated beverages, or exercise within 30 min before BP measurements.
• Ensure ≥5 min of quiet rest before BP measurements.
• Sit with back straight and supported (on a straight-backed dining chair, for example, rather than a sofa).
• Sit with feet flat on the floor and legs uncrossed.
• Keep arm supported on a flat surface (such as a table), with the upper arm at heart level.
• Bottom of the cuff should be placed directly above the antecubital fossa (bend of the elbow).
• Take at least 2 readings 1 min apart in morning before taking medications and in evening before supper. Optimally, measure and record BP daily. Ideally, obtain weekly BP readings beginning 2 weeks after a change in the treatment regimen and during the week before a clinic visit.
• Record all readings accurately:
• Monitors with built-in memory should be brought to all clinic appointments.
And, spoiler alert, it does matter if you cross or uncross your legs.
What Should The BP Goal Be?
For many patients with hypertension, SPRINT trial data published in 2015 suggest that a systolic blood pressure target of <120 mm Hg (intensive therapy) is preferable to a target of <140 mm Hg.
The SPRINT trial found that cardiovascular events like stroke and heart attack and death from these cardiovascular causes was lower by 25% in those patients treated intensively. Overall death was lower by 27%
Read my post on SPRINT here and have a discussion with your physician about whether these more stringent BP goals are right for you. Keep in mind that the technique used in SPRINT likely gives us lower BP than home self-monitoring.
“As a 64 year old who has emerged from his nonage with hypertension, I have carefully examined the latest American hypertension guidelines especially in light of the SPRINT study and elected to add a third anti-hypertensive agent to get my average BP below 130/80. It’s worked for me with minimal side effects but I carefully monitor my BP.
If I notice any symptoms (light-headed, fatigued) suggesting hypotension associated with systolic BP <120 mm Hg I tweak my medical regimen to allow a higher BP.
Like all of my patients I would prefer to be on less medications, not more but when it comes to enlightenment about the effects of hypertension, it is now clear that lower is better for most of us in our sixties down to at least 130/80*
Home Blood Pressure Monitoring Devices
You can get a good validated automatic BP monitor at Walgreens or CVS for around 35-40$.
But if you want to spend a little more you can get BP devices which have added features such as style, portability, BlueTooth communication with smartphone apps and perhaps most importantly connection through the cloud with your physician.
For my patients using Omron Bluetooth BP monitors plus Alivecor’s Kardia Mobile ECG and the KardiaPro cloud connection I can view their rhythm and blood pressure at any time and analyze summary data via my patient dashboard as below.Finally, be aware that scam methods of BP measurement are being promoted to the public.