Messerli and Bangalore use a second figure to graphically illustrate the potential consequences of the differing guidelines.
Cardiovascular death rates thus may vary three-fold depending on what BP goal we choose.
This marked variation in treatment recommendation highlights that they
are not only an evaluation and interpretation of evidence in question, but also a judgment weighted by personal, regulatory, and organizational preferences that can vary from physician to physician within a country and across geographical regions.
Physicians and patients (hopefully through shared decision making) are going to have to do some thinking on their own.
Messerli and Bangalore quote Immanuel Kant in this regard:
Enlightenment is man’s emergence from his self-imposed nonage. Nonage is the inability to use one’s own understanding without another’s guidance. This nonage is self-imposed if its cause lies not in lack of understanding but in indecision and lack of courage to use one’s own mind without another’s guidance. Dare to know! (Sapere aude.) “Have the courage to use your own understanding,” is therefore the motto of the enlightenment.
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*.
Sapere Audaciously Yours,
*N.B. In the SPRINT study the BP was obtained using an automatic BP cuff after 5 minutes of rest with the patient unobserved and averaging 3 recordings one minute apart.
This “research grade BP” averages about 12 mm Hg less than a routine single clinic obtained BP (see here.)
The FDA issued a press release July 13 announcing the voluntary recall of several drug products containing valsartan.
Valsartan is a generic, commonly used member of the drug class of angiotensin receptor blockers (ARBs) used for high blood pressure and heart failure and I have many patients on it. The brand name form of it (Diovan) does not appear to be on the recall list.
Per the FDA, the recall was
due to an impurity, N-nitrosodimethylamine (NDMA), which was found in the recalled products. However, not all products containing valsartan are being recalled. NDMA is classified as a probable human carcinogen (a substance that could cause cancer) based on results from laboratory tests. The presence of NDMA was unexpected and is thought to be related to changes in the way the active substance was manufactured.
If you are taking it read the following from the FDA to see if your particular manufacturer is included in the recall.
If your valsartan has been recalled contact your doctor for instructions. For my patients, most likely I will substitute another ARB called losartan which has very similar effectiveness and side effects.
Information for Patients and Health Care Professionals From The FDA
Because valsartan is used in medicines to treat serious medical conditions, patients taking the recalled valsartan-containing medicines should continue taking their medicine until they have a replacement product.
To determine whether a specific product has been recalled, patients should look at the drug name and company name on the label of their prescription bottle. If the information is not on the bottle, patients should contact the pharmacy that dispensed the medicine.
If a patient is taking one of the recalled medicines listed below, they should follow the recall instructions provided by the specific company. This information will be posted to the FDA’s website.
Patients should also contact their health care professional (the pharmacist who dispensed the medication or doctor who prescribed the medication) if their medicine is included in this recall to discuss their treatment, which may include another valsartan product not affected by this recall or an alternative treatment option.
The companies listed below are recalling all lots of non-expired products that contain the ingredient valsartan supplied by a third-party. Not all valsartan-containing medicines distributed in the United States have valsartan active pharmaceutical ingredient (API) supplied by this specific company. The supplier has stopped distributing its valsartan API and the FDA is working with the affected companies to reduce or eliminate the valsartan API impurity from future products.
Teva Pharmaceuticals Industries Ltd.
Teva Pharmaceuticals Industries Ltd.
“We have carefully assessed the valsartan-containing medications sold in the United States, and we’ve found that the valsartan sold by these specific companies does not meet our safety standards. This is why we’ve asked these companies to take immediate action to protect patients,” said Janet Woodcock, M.D., director of the FDA’s Center for Drug Evaluation and Research.
The new ACC/AHA guidelines for High Blood Pressure were published late last year and they were in favor of using home blood pressure measurement to aid in the management of hypertension.
I was happy to hear this as I am constantly advising my hypertensive patients to buy a home BP cuff, measure their BP once when they get up and again 12 hours later and report the values to me after two weeks.
I have not spent a lot of time instructing them on exactly how to make the measurement but the new guidelines do specify in detail how this should be done:
• Remain still:
• 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.
I monitor my own BP at home and often wonder whether there is scientific evidence to support such a rigid protocol. Being a contrarian and a skeptic, I typically violate 3/4 of the recommendations that are listed.
It seems like all of the instructions are guaranteed to give you the lowest BP you are likely to experience during the day. The vast majority of the time I am not sitting quietly with my legs uncrossed, my bladder empty and my back straight so following these directions will underestimate my average daily BP.
I’ve spent some time looking into all the instructions and they generally have some scientific studies to support them. For example, the position of the upper arm in relation to the heart does heavily influence BP readings (more on that in subsequent posts.)
The Mandate To Uncross The Legs
The instruction that most intrigued me was this one:
Sit with feet flat on the floor and legs uncrossed.
A number of questions came to the skeptical hypertensive:
What if you are on an exam table and your feet don’t reach the ground?
Does it really make a difference if your feet are flat on the ground versus slightly crooked?
Does any degree of leg crossing influence BP? Legs crossed at the ankles? Legs crossed at the knee?
And once I began thinking of leg crossing I realized that I spend a lot of my time with my legs crossed. Was this raising my blood pressure and my cardiovascular risk? Did I cross my legs because I liked the feel of a higher blood pressure?
The ACC/AHA guidelines are not alone in this recommendation-take a look at the British Health Service recommendation:
3.5. Measurements should be taken in silence when the patient is relaxed, with both feet flat on the floor and their back and arm supported. Many patients automatically cross their legs, which raises their blood pressure, so it is particularly important to emphasise the need for the patient to uncross their legs when taking their blood pressure.
Apparently the Brits believe that any ambient sound will alter the blood pressure. Talking is right out!
But if talking, ambient sounds and crossing your legs raises your blood pressure shouldn’t we be advising patients to spend their days wearing ear plugs in silence with their legs uncrossed?
Scientific Studies On Leg Crossing
It turns out there are good studies showing that leg crossing raises your blood pressure.
The first was published in 1999 and involved 53 hypertensive and 50 normotensive subjects.
Participants were randomly assigned, using a cross over design to having seated blood pressures measured with their leg in three different postures
Feet flat on the floor and legs uncrossed
Legs crossed , method 1-popliteal fossa of the dominant leg over the suprapatellar bursa of the non-dominant leg.
Legs crossed, method 2- lateral malleolus (which the article spells mallelous) of the dominant leg over the suprapatellar bursa of the non-dominant leg.
I love the efforts these Calgarian investigators went to in this study to ensure blinding (although spelling is clearly not their forte’). They state “blood pressures were measured by one investigator who was behind a screen and blinded to the leg position of the patient while a second investighator (sic) ensured that the subject assumed the proper leg position.”
Systolic blood pressure in patients with hypertension increased by 8 mm Hg by method 1 leg crossing and 10 mm Hg by method 2.
Another study demonstrated that although crossing the legs at the knees influenced blood pressure, crossing them at the ankles had no effect.
If leg crossing raises the systolic blood pressure 8 to 10 mm Hg why aren’t we doctors recommending patients sit with leg uncrossed the majority of the time. Personally, I had never heard there were any health complications to sitting with my legs crossed.
Apparently the myriad health information sources on the internet are near unanimous in their condemnation of leg crossing but the hypertensive effect of this maneuver is usually not cited.
I must admit since doing this bit of research I have substantially reduced the amount of time I sit with my legs crossed. And I’ve pondered extensively whether sitting with legs crossed makes me feel any different and why I suddenly and seemingly randomly decide to cross my legs.
I’ve also started asking friends and colleagues and medical residents how much of the day they spend with legs crossed.
On teaching rounds one morning recently we tested a volunteer resident’s blood pressure with legs crossed and uncrossed. Sure enough, the systolic BP was 10 mm Hg higher with legs crossed.
For those of you itching to read more about BP and leg crossing here are the references:
Pinar R, Ataalkin S, Watson R. The effect of crossing legs on blood pressure in hypertensive patients. J Clin Nurs 2010; 19:1284–1288. [PubMed]
Adiyaman A, Tosun N, Elving LD, Deinum J, Lenders JWM, Thien T. The effect of crossing legs on blood pressure. Blood Press Monit 2007; 12:189–193. [PubMed]
Pinar R, Sabuncu N, Oksay A. Effects of crossed leg on blood pressure. Blood Press 2004; 13:252–254. [PubMed]
Avvampato CS. Effect of one leg crossed over the other at the knee on blood pressure in hypertensive patients. Nephrol Nurs J 2001; 28:325–328. [PubMed]
Keele-Smith R, Price-Daniel C. Effects of crossing legs on blood pressure measurement. Clin Nurs Res 2001; 10:202–213. [PubMed]
Foster-Fitzpatrick L, Ortiz A, Sibilano H, Marcantonio R, Braun LT. The effects of crossed leg on blood pressure measurement. Nurs Res 1999; 48:105–108. [PubMed]
Peters GL, Binder SK, Campbell NR. The effect of crossing legs on blood pressure: a randomized single-blind cross-over study. Blood Press Monit 1999; 4:97–101. [PubMed]
As December draws ever closer to the twenty-fifth you may find yourself behind the wheel of a large automobile puzzling over the perfect gift for your loved ones.
Fear not, for the skeptical cardiologist has a few suggestions to help you.
The Omron 10 Blood Pressure Monitor
If your hypertensive friend or relative already has all the standard BP paraphernalia (pill splitter, basic BP cuff), owns a smart phone and has an engineer or scientist approach to data the Omron 10 (BP786, 59.99$ at Best buy.com) just might be the perfect gift.
The skeptical cardiologist recently purchased two (that’s right two) of these in anticipation of Christmas.
Christmas arrives with multiple stressors guaranteed to hike your blood pressure.
The Omron 10 offered three features not available on my basic Walgreen’s BP cuff that I felt were possibly useful:
Averaging/automating three consecutive readings. After reading about the SPRINT BP trial which showed a benefit of aiming for SBP of 120 over 140, I thought I should try to reproduce the method used in the trial. This involved measuring BP 3 times separated by 5 minutes and averaging the results. The Omron 10 can be set to make and average three BP readings separated by a variable time period.
The ability to communicate with an iPhone or Android smartphone and record and display the data in an app.
Works off both batteries and plug in electrical power.
I thought my dad (a retired chemist) would like the Omron 10’s features but, alas, he informed me that if he wanted to average three BP readings he could just write down the numbers and do the math.
If he had an iPhone he might really like the way the Omron sends its data to the free Omron app.
The app displays BP and heart rate readings recorded for different time intervals.
You can take a screen shot like I did here or email it and share the data with your doctor through the doctor’s patient portal!
I’ve mentioned this really cool device a few times (here and here).
It is now listed on Amazon.com for $57 (a significant drop from when I purchased it) and can be attached to your smartphone case. It does a really good job of recording a single lead electrocardiogram (ECG) and diagnosing normality or atrial fibrillation.
If your friend or loved one is experiencing periodic fluttering in their chest or a sensation of the heart skipping beats or racing (the general term for which is palpitations) then this could be the perfect gift.
A number of my patients have purchased these and have made ECG recordings which I can review online.
Primarily I have been recommending them to my patients who have atrial fibrillation periodically.
You may think this is too complicated a device to master but last week I saw in my office a 94 year old lady who had had an episode of atrial fibrillation earlier in the year. Since her last visit she had purchased an AliveCor device and was able to show me the ECG recordings she had made on her iPhone.
May your holiday season be joyous, full of loved ones and free of stressors that raise your blood pressure and cause your heart to pound and race. But if it is not, consider purchasing one of these nifty devices.
Would you rather have a systolic blood pressure (BP) of 120 mm Hg or 140 mm Hg?
Prior to a week ago this sometimes skeptical cardiologist thought treating hypertensive patients to the lower BP didn’t necessarily help avoid death from cardiovascular disease, heart attacks or strokes and that it resulted in more side effects.
Clinical trials have shown that treatment of hypertension reduces the risk of cardiovascular disease outcomes, including stroke (by 35 to 40%), heart attacks (by 15 to 25%), and heart failure (by up to 64%) but the target for systolic blood-pressure lowering has been uncertain.
The SPRINT trial randomized almost ten thousand patients and compared the effects of antihypertensive treatment with a systolic blood pressure (SBP) target of <120 mm Hg (intensive treatment) versus <140 mm Hg (standard treatment).
They studied hypertensive adults ≥50 years of age who had an average SBP of 130–180 mm Hg (the acceptable upper limit decreasing as the number of pretrial antihypertensive medications increased) and were at additional risk for cardiovascular disease (CVD).SPRINT was designed to recruit study participants with an average CVD risk of ≈2% per year, equivalent to a Framingham 10-year CVD risk score of 20%.
To understand if these trial results apply to you it is important to know what patients were enrolled in the study (inclusion and exclusion criteria) and I’ve listed these at the end of this post.
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%
Average systolic blood pressure was 121 mm HG in the intensive therapy group and 134 mm Hg in the standard therapy group.
Drugs used were: thiazide-type diuretics, calcium channels blockers, and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Other agents, including spironolactone, amiloride, β-blockers, vasodilators, or α-receptor blockers, could be added if necessary. On average, 2.8 drugs were used in the lower BP group versus 1.8 in the higher BP group.
This more intensive BP treatment was surprisingly well tolerated. Very surprisingly, orthostatic hypotension, (drop in BP on standing I talked about in my post on burpees and dizziness) was significantly more common in the standard than in the intensive arm. I would have expected this opposite.
There were significantly more kidney problems and electrolyte abnormalities in the intensive group compared to the standard therapy group.
This study provides a very powerful argument for shooting for a BP of 120 in many of my patients.
It’s important to replicate how BP was measured in the SPRINT trial if we are to apply the results. As the authors have written elsewhere:
“be mindful of the manner in which BP was measured in the trial: an average of 3 office BP readings taken with proper cuff size, participants seated with their back supported, 5 minutes of rest before measurement, and no conversation during the rest period or BP determinations. In SPRINT, this was achieved using an automated manometer (Omron Healthcare, Lake Forest, IL) that was preset to wait for 5 minutes before measurement, as well as to take and average the 3 readings. BP measurements taken without observing these conditions are likely to overestimate BP6 and result in over treatment, with the potential for higher rates of serious adverse effects and greater utilization of resources.”
And the entry criteria:
Increased cardiovascular risk was defined by one or more of the following: clinical or subclinical cardiovascular disease other than stroke; chronic kidney disease, excluding polycystic kidney disease, with an estimated glomerular filtration rate (eGFR) of 20 to less than 60 ml per minute per 1.73 m2 of body-surface area, calculated with the use of the four-variable Modification of Diet in Renal Disease equation; a 10-year risk of cardiovascular disease of 15% or greater on the basis of the Framingham risk score; or an age of 75 years or older. Patients with diabetes mellitus or prior stroke were excluded
“the intervention in this trial, which carefully adjusts the amount or type of blood pressure medication to achieve a target systolic pressure of 120 millimeters of mercury (mm Hg), reduced rates of cardiovascular events, such as heart attack and heart failure, as well as stroke, by almost a third and the risk of death by almost a quarter, as compared to the target systolic pressure of 140 mm Hg”
These data won’t be published for several months but if they hold up under close scientific scrutiny it will change the way I and other physicians treat hypertension dramatically.
The lower BP goal patients in this study were on three BP meds versus two for the higher goal. To achieve a goal of 120 mm Hg I think it is highly likely that I will have to add an additional BP med to all of my patients.
With more stringent BP goals it will become crucial to make sure that we are getting accurate BP data on our patients. But what kind of BP data should we be looking at and what technique for obtaining the BP should be employed?
Home Versus Office Blood Pressure
Every patient I see in my office gets a BP check. This is typically done by one of the office assistants who is “rooming” the patient using the classic method with , listening with stethoscope for Korotkov sounds. If the BP seems unexpectedly high or low I will recheck it myself.
Often the BP we record is significantly higher than what the patient has been getting at home or at other physician offices.
There are multiple factors that could be raising the office BP: mental stress from driving to the doctor or being hurried or physical stress from walking from the parking lot.
Conscious or subconscious anxiety about what the doctor may find is thought to play a role, so-called “white coat” effects.
Consequently I rely more on home BP monitoring when making decisions on treatment initiation or change
Accurate automatic BP devices can be purchased from Walgreen’s or CVS for around $40.
I recommend devices that have a cuff that goes around the upper arm and have as few frills as possible.
I usually ask patients to take a BP in the morning and evening daily for two weeks and report the values to me.
Avoid caffeinated or alcoholic beverages, and don’t smoke, during the 30 minutes before the test.
Sit quietly for five minutes with your back supported and feet on the floor.
When making the measurement, support your arm so your elbow is at the level of your heart.
Push your sleeves out of the way and wrap the cuff over bare skin.
Measure your blood pressure according to the machine’s instructions. Leave the deflated cuff in place, wait a minute, then take a second reading. If the readings are close, average them. If not, repeat again and average the three readings.
Don’t be too concerned if a reading is high. Relax for a few minutes and try again.
What is the True Blood Pressure?
It seems to me that the most important thing in blood pressure control is what the blood pressure is the majority of the time. Consequently I have always questioned the advice to throw out high readings and to only utilize BP measurements obtained after sitting quietly for 5 minutes.
After all, if you are active most of the day as you should be, it would be rare for you to be sitting quietly doing nothing for 5 minutes. The BP you first take, although higher than one 5 minutes later, might be a more accurate reflection of your average BP during the day.
Most days you are exposed to a variety of stressors related to work or personal and family situations and your BP is likely reacting to these stressors. The “sitting quietly for 5 minutes” BP is not reflective of these higher readings.
In addition, if you only take your BP when your bladder has just been emptied and you have not had any caffeine it is likely an underestimate of the average daily BP which includes full bladders and cups of coffee.
For these reasons I only tell my patients to take the BP twice a day. I don’t instruct them to sit quietly or throw out the high readings or avoid caffeine. I want BPSs that truly represent the normal daily fluctuations. I don’t want to cherry pick “good” BPs.
I am eagerly awaiting the publication of the SPRINT data which may alter BP treatment dramatically.
Until then I’m sticking to the guidelines published two years ago (and which I wrote about here) which aimed for SBP <140 mm Hg for patients less than 60 years and <150 mm Hg for those older than 60.
The first day I tried to measure my salt consumption was one of the hottest we have had this summer in St. Louis with the thermometer reaching the high 90s and the heat index well over 100. In the midst of this heat I rode my bike to my local gym, worked out on the elliptical for about 35 minutes then rode home. Although the distance i rode was not far (maybe 3 miles) I was sweating profusely.
This profuse sweating was not the norm for me but it clearly was changing my salt “balance” for the day. The optimal amount of salt to consume may be controversial but clearly the more you sweat the more salt you should consume to replace the lost sodium.
“The recommendation for less than 1500 mg/day does not apply to people who lose large amounts of sodium in sweat, such as competitive athletes and workers exposed to extreme heat stress (for example, foundry workers and fire fighters)”
I was back on my elliptical today (after a bike ride that resulted in no sweating) and watched the men playing the round of 16 in The US Open Tennis Tournament on the large TV screens conveniently placed to entertain me. Temperatures have been unusually high In NYC this week and the players have been suffering as a result. The men play best of 5 sets and matches routinely last longer than 3 hours played in the heat of the day with full sun exposure.
Scientists have studied professional tennis players and measured their sweat loss to be as high as 2.5 L/ hour while playing singles in hot circumstances. A liter of sweat contains around 920 mg of sodium.
That means these guys are losing 2.3 grams of sodium per hour of tennis played! This happens to be one teaspoon of salt and equal to the more moderate limit on sodium consumption (compared to the AHA) of the USDA. Clearly, consumption of salt on the order of 8 grams/ day would be needed in these circumstances to maintain salt balance and acceptable sodium levels in the blood.
How much are more normal individuals losing daily and how much does that vary depending on activity, ambient temperature and humidity?
The simple answer has to be that no authority knows the amount of salt each individual loses daily. Sweating and salt loss vary widely between individuals and over time in the same individuals.
It is common for my patients to note that during the summer months their blood pressure drops when they spend time gardening or if they have a job that requires heavy exertion in hot conditions. Often a downward adjustment in blood pressure medications is needed to account for this (especially if a diuretic is one of their BP drugs).
These variations in salt loss in the context of large variations in cardiovascular physiology and blood pressure regulation between individuals is further support for abandoning the ultra-low salt limits suggested by the AHA and the USDA.
Moderation may not be best for all things in diet (processed foods and added sugar come to mind) but for salt consumption moderation appears best.
He is embarrassed to admit this, but the skeptical cardiologist has no idea how much salt he consumes.
I have never stressed to my patients that they engage in obsessive assessment of their salt consumption. The data that everyone needs to limit salt consumption to , say 1.5 grams/ day, as the AHA recommends are not compelling. If asked, my typical response is to recommend not adding additional table salt from the salt shaker and to avoid processed and fast foods (which apparently accounts for 75% of salt consumed in the US).
I definitely have some patients with hypertension and some with heart failure in whom watching for excessive salt consumption is important. One of my patients with fairly well controlled hypertension called me last week because he was recording blood pressures of 210/120. Before I could add another blood pressure agent he had decided to stop adding the salt to the tomatoes he was eating and over a period of a week the blood pressure came back to normal values. Manyl of my severe heart failure patients will report weight gain due to ankle swelling after a particularly salty meal.
On the other hand, I have many patients who are symptomatic from low blood pressure. These patients have frequent episodes of dizziness and have been following the recommended low salt diet thinking that this was enhancing their health. When I get them to liberalize salt intake, blood pressures and their symptoms go away.
Recent papers on salt consumption suggest that either too much or too little salt is bad for you and consequently the public must be totally confused on what they should be doing.
Since I have high blood pressure which seems to randomly fluctuate I’ve decided to try to measure exactly how much salt I consume daily. Maybe I am consuming more than 5 grams daily (I think that is too much).
This is not going to be an easy task. If i eat out during this time I’m not sure how I will have any clue what amount of salt is in the meal. If I decided to fry a couple of eggs this morning , I will shake some salt on them from the salt cellar. Is it possible to measure this amount? If I put some cheese on the eggs, will I need to precisely measure the amount of cheese? Looks like there are some free iPhone apps I can utilize to assist me in the process.
To my readers and patients, please join me in this exciting and informative adventure. Over the next week, try to track your daily salt consumption and report the numbers to me. Or do it for one day. The Great Salt Measurement Challenge is On!