Just 50 years ago high blood pressure was considered part of the normal aging process and not treatable – and thus was considered “essential” hypertension. A large multi-center VA trial began in the 1950s using the diuretic thiazide was published in 1967. This and several additional landmark trials, including HDFP (1979) and MRFIT (1980) demonstrated that in both men and women lowering the diastolic (lower) blood pressure number below 90 reduced cardiovascular events including stroke and heart failure while reducing mortality (risk of death). By about 1980 the treatment goal of reducing DBP below 90 became the standard of care.
It wasn’t until the SHEP trial 1991 that reducing isolated systolic blood pressure above 160mmHg, especially in the elderly, was adopted as a treatment goal as well. In 1993 the TOMHS study demonstrated that treatment of hypertension with both medication and lifestyle was superior to medication alone. Then in 1997 the DASH trial was able to show that lifestyle alone including salt restriction was able to reduce blood pressure significantly. The HOT trial in 1998 looked at whether lowering the DBP further comparing targets of 90mmHG, 85mmHg or 80mmHg and found no significant difference, though the distinctions between the three groups was not as great as the investigators had hoped.
I major study (SPRINT) that began in 2009 followed 9300 men and women over 50 compared a group with blood pressure below 140 and a similar group who achieved a blood pressure of below 120. They found a 25% reduction in deaths and a 33% reduction in heart attacks, strokes and heart failure. This is a greater reduction in risk than lowering cholesterol. So a team of 21 subject matter experts determined that the goals of treatment should be changed to reflect this new landmark study and the preponderance of available evidence.
So what are these “new” guidelines, and why were they released and by who? Here is a chart I created to try and categorize the new goals:
| Blood Pressure Guidelines | ||
| Previous Target | New Target | |
| Normal | <130/90 | <120/80 |
| Prehypertension | 130-90-140/90 | 120/80-130/80 |
| Stage I Hypertension | 140/90 – 150/100 | 130/80-140/90 |
| Stage II Hypertension | >150/100 | >140/90 |
Both the American College of Cardiology and American Heart Association have adopted these new guidelines after an updated review of the literature by 21 experts looking at the risk of high blood pressure. Based on these new categories 46% rather than 32% of the U.S. adult population will be categorized as hypertensive. The experts who helped establish these new levels make it clear that those with Stage I hypertension should not necessarily be started on medication, but rather encouraged to use lifestyle changes for treatment. This means more exercise, less salt, reduced alcohol intake and weight loss. Some may ask if there was a conflict of interest among the experts who developed these new guidelines. The National Heart, Lung, and Blood Institute has has clear rules to address potential conflicts of interest or relationships with industry that I believe make the conclusions as free from bias in these areas as possible.
My Take
It has always been important to target the lowest blood pressure reasonably possible, understanding that in general the lower the better. I see these changes as encouraging physicians to make lifestyle changes more important earlier and for those who do require treatment, targeting a more aggressive end point of <120/80 rather than <130/90. I always say that in general it’s not the medicine that reduces risk, it’s reaching the goal that makes the difference. No one is ACE Inhibitor deficient!
We know that the combination of medication and lifestyle changes are more effective than medication alone so I anticipate really pressing lifestyle changes to reach the more aggressive goals, rather than adding more medication. This should be a good thing for not just blood pressure reduction, but for optimizing other areas of good health such as lowering blood lipids, and reducing the risk of diabetes. After all blood pressure is just one of several risk factors for cardiovascular disease that can be improved through proper nutrition, regular exercise, healthy life habits and achieving a healthy body weight.
You should work to reduce your blood pressure through eating a healthy diet, exercising daily, maintaining a healthy weight, stopping smoking, getting plenty of sleep and managing the stress in you life. Remember that in general the lower the better, obviously there are times where blood pressure can be too low. You should never have symptoms related to low blood pressure. If you are on medication and your blood pressure now falls into the Stage I hypertensive range it is worth talking to your doctor about whether adjusting your treatment makes sense for you to reach the new targets of therapy. One thing is for sure, high blood pressure is not “Essential”!