HIGH BLOOD PRESSURE | WHEN TO TREAT
When to treat high blood pressure (HBP) remains a major topic of conversation with confusing recommendations issued by different organizations. Without question HBP ranks as a major cause of hardening of the arteries, stroke, heart attacks, heart failure, kidney malfunction, cardiovascular related death and dementia. Actually HBP related conditions represent the second leading cause of preventable death in the United States behind only cigarette smoking.
While medical experts express unanimity in their clarion call to treat HBP with appropriate therapy, agreement falters and arguments begin over the most basic elements on what constitutes HBP, how to measure it, when does the risk of harm become sufficiently great to warrant treatment and whether to begin a regimen of lifestyle modification versus oral medication.
BLOOD PRESSURE OVER TIME
In America blood pressure characteristically rises in parallel with age. In the not too distant past a popular adage suggested an appropriate level for the upper number or systolic level was 120 plus a person’s age. Fortunately this concept appears relegated to the long list of discarded, but once prevalent ideas. In the period before his death, Franklin Roosevelt’s blood pressure readings approaching and then exceeding 200 mm elicited only minimal concern from his doctors.
Actually examining native tribes isolated from western influence provides quite startling information. HBP basically does not exist even among the eldest octogenarians. However when they migrate to other areas or other nations where dietary factors, excessive salt consumption, lack of exercise and greater stress align with our American habits, blood pressure steadily rises and the rate of HBP approximates our own.
ACCURATELY MEASURING BLOOD PRESSURE
But even before discussing treatment of excessively elevated blood pressure, we must agree on a standardized approach to measuring it. Simply slapping a cuff on your arm and obtaining a reading fails to provide an accurate assessment of the blood pressure. For most individuals at least 2 readings should be obtained on at least 2 separate occasions before confirming the diagnosis of HBP. Additionally a person should be seated comfortably with the arm supported at chest height on a desk or table. For at least 30-60 minutes prior to testing cigarettes, caffeine and alcohol must be avoided and the individual should have an empty bladder.
Additionally in our society where obesity affects at least 1/3 of the adult population, an appropriately sized blood pressure cuff must be utilized. A device aimed at an average sized individual guarantees an incorrect result in those with excessive upper arm circumference. Many older individuals remain more comfortable with the old fashioned manual devices where the health care worker pumps air into the cuff and listens with a stethoscope; they incorrectly believe these antique sphygmomanometers guarantee more accurate results.
Actually automated devices remain more convenient and provide equivalent readings. Until recently blood pressure readings remained the sole provenance of medical professionals. Recent trends encourage out of clinic monitoring which offer a variety of advantages including identifying so-called white coat hypertension and its opposite masked hypertension. Of course the same protocol applies regarding multiple readings and avoidance of factors associated with incorrect readings. Since blood pressure normally fluctuates often quite dramatically within the course of a day, home measurements provide a more realistic assessment compared to those obtained in a medical setting.
SYSTOLIC OR DIASTOLIC
Overall for adults the upper number, the systolic pressure, remains more important than the lower number or diastolic pressure which actually tends to decrease with advancing years. Traditionally normal systolic blood pressure ranged up to 120 mm, borderline hypertension existed when the numbers extended between 120 mm – 140 mm with Stage 1 hypertension defined as systolic pressure of 140 – 160 mm and the more dangerous Stage 2 hypertension anything above that value.
Realizing the risk for HBP related complications parallels the extent of the systolic elevation, various professional societies provided their own guidelines for levels where the expected benefits exceeded the risk associated with therapy, the nuisance of periodically returning to the medical office and the expense of the medication and any associated blood testing. More recently additional attention focuses on the psychological impact of an otherwise healthy individual designated as suffering from a “disease.”
COMPLICATIONS – RISK
Another recent modification in our understanding of risk includes an awareness of the global likelihood of developing a cardiovascular complication. Unquestionably a blood pressure of 160 mm carries a greater risk than 140 mm. Now with our more holistic approach, we consider other
factors too. So a reading of 160 mm in a sedentary obese cigarette smoker with diabetes and elevated cholesterol understandably increases the risk of an adverse outcome compared to someone with the same blood pressure but absent the other factors.
ONLY RECENT AWARENESS
Surprisingly widespread medical recognition of the harm associated with HBP only dates back to the 1960s with publication of the Veterans Administration Cooperative Research Program article detailing the benefits of lowering diastolic levels from initial values of 115 mm – 129 mm to about 90 mm. Attention did not focus on the more common systolic hypertension until the 1991 publication of the Isolated Systolic Hypertension in the Elderly Report. This study demonstrated the value of reducing the upper number to a level below 160 mm.
With this newly acquired information available, a host of professional societies proposed different levels they believed should trigger some medical intervention. While everyone agrees that 160 mm demonstrably increases risk of an adverse event, some guidelines suggest a safer threshold would be 140 mm. A minority of organizations throughout the world opt for other numbers but all recognize that greater benefits accrue to those with reduction from 160 mm to 150 mm than for those who begin with a level of 140 mm and reduce it to 130 mm.
UNREALISTIC GUIDELINES BUT ONLY FROM 2 ORGANIZATIONS
Against this background, in November 2017 the American College of Cardiology in conjunction with the American Heart Association published what I believe are incomprehensible and very inappropriate guidelines. Basically they redefine high blood pressure. Now normal is less than 120 mm, elevated
levels are 120-130 mm with Stage 1 high blood pressure between 130-140 mm and Stage 2 HBP above 140 mm.
According to new criteria about 50% of people over age 50 are labeled hypertensive and this figure rises to about 80% for those beyond age 65. And of course the corollary to this involves more doctor visits, pills and expense even in the absence of the real probability of major benefit.
Are these new recommendations based on some dramatic recent increase in cardiovascular events? Examining the cardiovascular mortality data since 1970 reveals a steady, continuous downward slope of disease. But what appears to have prompted the sudden change is the SPRINT trial published in the prestigious New England Journal of Medicine in November 2015.
WHAT CAUSED A CHANGE IN ADVICE?
Investigators planned a 5 year study of adults over age 50 already with high blood pressure and on therapy. More than 9000 participants were divided into 2 groups with the goal to reduce the systolic levels to either to below 120 mm – the intensive treatment group or to between 135 – 140 mm – the standard group. At least one elevated risk factor for cardiovascular disease existed in all individuals in the form of a previous heart attack, stent, peripheral vascular disease, moderately reduced kidney function or being at least age 75. Other risk factors included coronary artery calcium or in excess of 15% calculated 10 year risk of cardiovascular disease based on the Framingham Risk Scale. Actually the risk of an adverse event averaged 25% at entry. Stroke and diabetes excluded an individual from participation.
About half took statins to lower their cholesterol, most were overweight or obese, fewer than half never smoked cigarettes and about 1 in 7 currently used nicotine products. The average number of medicines for HBP was about 2 at entry with a blood pressure in both groups averaging 140 mm systolic.
After excluding about 5000 people for one reason or another, 9361 began the study. Initially evaluated in clinic every month for 3 visits this was extended to every 3 months after achieving the appropriate level of control for the treatment group – intense or standard. Medicines included the standard water pills, ACE inhibitors, angiotensin receptor blockers and calcium blockers.
TOO MANY PILLS
Patients in the intensive group were able to reduce their systolic levels to an average of 121 mm taking about 3 anti-hypertensive drugs while in the standard group the blood pressure fell to 136 with slightly fewer than 2 drugs. Actually in the intensive treatment group about 1 in 4 took 4 or more drugs for blood pressure control with another 1 in 3 required 3 drugs. So more than 50% of participants in the intensive treatment group received 3 or more drugs. And remember the average blood pressure was 121 mm in spite of all that medicine, not the goal of less than 120 mm.
According to directions from the Data and Safety Monitoring Board, the study was terminated a little beyond 3 years of the anticipated 5 years originally planned. According to this overseeing unit the results clearly separated the groups and necessitated an abrupt end.
So were the outcomes really all that dramatic as to warrant breaking the code and in effect establishing the basis for the new blood pressure guidelines? Let’s look deeper into the matter. The primary end point was the sum of certain events: heart attack, acute coronary syndrome also referred to as pre-infarction chest pain or angina, stroke, heart failure and death from cardiovascular causes.
Unfortunately medical studies often report their results in this manner which tends to blur the importance of the true meaning since the significance of the individual components remains unequal.
SPRINT TRIAL – MAYBE NOT WHAT IT SEEMS
Headlines from the SPRINT trial proclaim a 25% reduction in the combined primary endpoint which certainly at first glance seems quite dramatic. But the 25% reduction represents a relative reduction not an absolute reduction. The difference between these terms carries major impact on understanding the study.
STATISTICAL SLEIGHT OF HAND
A moment of diversion to explain. Imagine two piles each with 100 pennies. Remove 1 penny from the first stack and 2 pennies from the second. The change in the first pile equals 1% while that in the second is 2%. Now examine the differences. The absolute difference is 1 penny or 1% of the original mound but a statistician would refer to the relative difference as 100%: 2 instead of 1. In either event were you to look at the original mass, no obvious difference would exist – 99% of the pennies would remain in the first group with 98% in the second group.
Now back to the SPRINT study. In the intensive group the annual rate of all of those combined events was 1.65% while in the standard treatment group 2.19% experienced an event. When an ordinary person looks at these numbers, the absolute difference is only 0.54%, certainly not an attention grabbing number. And in spite of their high risk, at the 1 year anniversary about 98% of both groups remained free of new onset adverse events.
And studying the component parts seems equally unimpressive which of course belies the reason for combining a laundry list of seemingly untoward events. The likelihood of a heart attack between the intensive group and the standard group was not statistically different, ditto for acute coronary syndrome with the same lack of difference for stroke. Death from cardiovascular causes reached the necessary threshold: 0.8% in the intensive treatment group and 1.4% among those receiving standard treatment – a 57% relative reduction which in this case translates into a 0.6% absolute reduction. In any event about 99% of the participants in each group were alive at 1 year which to most casual observers makes the 57% reduction in death from cardiovascular causes not only seem meaningless but grossly misleading.
In fact the table present in the study comparing the primary combined outcomes in the intense treatment and standard groups basically looked identical – almost perfectly overlapping. The same situation existed with the graph for death from any cause. Only after magnifying the ordinates by one log or 10 fold was there an any light between the two: to some this represents a sleight of hand worthy of David Copperfield”s magic.
COMPLICATIONS OF THERAPY
All medicines pose threats a problem magnified among older individuals and those more fragile. So what were the adverse reactions in this study? In the intensive group 220 individuals or 4.7% suffered a serious event probably or definitely related to their treatment. In the standard treatment group only 118 people suffered the same kind of toxicity. Now does this represent an 88% relative increase in complications or a 2.2% absolute difference. If the authors refer to a 25% reduction in primary events, then they must allow an 88% increase in serious side effects. Now you understand why benefits are always reported in relative terms while complications appear as absolute values.
Among the major problems associated with intensive treatment were fainting, excessively low blood pressure, acute kidney malfunction, visits to the emergency room and electrolyte abnormalities – abnormal sodium and potassium.
A follow up evaluation praised the SPRINT trial as a cost effective model suggesting only about an additional $50,000 to gain what is referred to as an additional single quality of life year. Unfortunately there appears to be an almost 50% probability the cost would be even greater.
TYPICAL CAUSES OF HIGH BLOOD PRESSURE
So back to the beginning. It is important to realize for most of us HBP represents a failure to control our environment, lifestyle and habits. Remember the Kuna Indians and other native tribes untouched in their pristine environments separated from western influences. In America on the other hand, 1/3 of us are overweight with another 1/3 falling into the obese category. Type 2 or adult onset diabetes, generally due to excessive body weight, affects nearly 1 in 10 with pre-diabetes in almost 2.5 times this number.
We consume far too much salt. Most people falsely believe that salt added at the table or in cooking represents the majority of dietary sodium. Salt in bread, cookies, bacon, processed meats, soups, tomato sauce, cheese, pizza and fast food represents about 90% of our daily intake, an intake that should be no more than 2400 mg a day and preferably only 1500 mg.
ATTENTION TO DIET AND LIFESTYLE TRUMPS MEDICINE
Arguments abound over what constitutes an appropriate diet. Portion control remains central with generous quantities of fruit, vegetables and nuts. Fish and chicken are probably preferable to meat. The dispute regarding high fat, high protein versus low fat, high carbohydrates remains unresolved but increasingly veers toward all forms of fat rather than simple sugars. Nevertheless, calories need to be limited with some advocating health benefits of an occasional fast.
Even after decades of warnings cigarette smoking still remains far too common and an extraordinary number of people consume excessive alcohol on a regular basis. Men should limit themselves to 2 daily units of alcohol with only 1 for women. A unit represents a standard 5 ounces of wine, a 12 ounce beer or 1.5 ounces of spirits. Exposure to excessive amounts of either remain major contributors to cardiovascular disease.
In spite of an abundance of gyms and fitness centers, we opt to spend our free time on smart phones, tablets of computers and watch far too much television. Exercise remains central to maintaining proper weight but only when combined with diet. For most of us, exercise by itself will not result in weight loss and may stimulate appetite and lead to weight gain.
BUT LIFESTYLE MODIFICATION USUALLY FAILS
Every family doctor, general practitioner, internist and cardiologist proclaims the benefits of lifestyle modification, weight loss, exercise and stress reduction. Yet when confronted by someone with HBP, these healthcare professionals almost reflexively reache for the prescription pad and write for one and then another medicine. They neglect the hygienic measures just outlined. The likelihood of success – limited.
Unfortunately the community physicians are not alone in overlooking the essential nature of lifestyle modification. Consider the SPRINT trial. You should expect a study funded by the National Heart Lung and Blood Institute, a division of the National Institutes of Health to demand attention to these dietary and lifestyle issues. But in the entire 261 page protocol, advice on diet, weight reduction and stress control occupied only ½ of a single page. And surprisingly the budget for the study neglected to include any funds to support the various clinics devoting sufficient time and effort to this important matter.
BACK TO BASICS FOR SUCCESS
If your real intent is to reduce your likelihood of experiencing a premature cardiovascular event – stroke or heart attack, perhaps a new approach might prove beneficial. Rather than simply taking a pill which provides less than the expected benefit for most of us, consider simple dietary modification. The changes outlined actually lower the blood pressure as much as taking an anti-hypertensive medication. Doses of all drugs are geared to lower the systolic reading by about 10 mm which melds perfectly with what diet and exercise offer.
Now if the goal is reducing overall cardiovascular risk, it’s important to realize for the overwhelming majority of us with mild elevation of blood pressure, the added benefit of following what people loosely refer to as a Mediterranean diet seems prudent. This includes at least 3 daily servings of nuts, fruit and legumes with at least an additional 2 servings of vegetables. Fish should be consumed at least 3 times each week with white meat substituted for red. For men 2 glasses of wine are allowed each day with only 1 for women. Extra virgin olive oil should be the primary oil used for cooking and salads. Sodium must be greatly reduced.
Not only will these simple changes especially when coupled with sufficient exercise improve blood pressure control, but they dramatically reduce the probability of heart attack, stroke and even cancer. Even if the blood pressure remains above 140 mm, adding standard medicines provide enhanced results compared to the same medicine in those not following the diet.
PILLS, PILLS, AND MORE PILLS
Unfortunately our society believes in pills – pills for blood pressure, pills for diabetes, pills for high cholesterol, pills for pain, pills for anxiety, pills for depression and the list seems to forever expand. People fail to realize that the drugs we so readily consume lack the benefits we assume. To achieve successful mastery of your body and maintain health for as long as possible requires a dramatic change in habits. While we attempt all sorts of shortcuts until our health begins to fail, it behooves us to pay attention to life’s simple essentials – diet and exercise. And then only if necessary, a pill for the appropriate indication. Not following these simple rules guarantees full employment for doctors and bountiful profits for drug companies.
Incorporating this information into a treatment algorithm depends on interpretation of the available evidence from studies involving large numbers of people and following them over lengthy intervals. The American Heart Association and American College of Cardiology offer a web based calculator available to anyone. It calculates the estimated 10 year probability of a cardiovascular event. While a 10% risk spread out over 10 years meets American threshold for treatment, these numbers fail to achieve universal acceptance. Other equally sophisticated nations prefer different more lenient guidelines.
But as with everything in life, the picture may be less rosy than it appears. Prior to its publication, an eminent cardiologist from the Cleveland Clinic among others pointed out the calculator overestimated risk by 75-150%. That argument failed to deter the organizations from making the calculator widely available.