A “Touch” of High Blood Pressure

It has been recognized for many years that an elevation of blood pressure from optimal levels of <120/80 mm Hg will increase cardiovascular risk. ¹ , ² , ³ In recent years, more attention has been paid to slightly elevated or so‐called high‐normal blood pressures (systolic pressure of 120–139 mm Hg or diastolic pressure of 85–89 mm Hg). Although a higher risk of cardiovascular disease mortality in people with high‐normal pressures than in those with optimal pressures (<120/80 mm Hg) has been documented, the degree of risk for nonfatal cardiovascular events has not been well quantified until recently. ⁴

Several studies have shown that people with high‐normal blood pressures not only may have changes in cardiac morphology and carotid arteries, suggesting early atherosclerosis, but also changes in left ventricular diastolic function, when compared to individuals with lower blood pressures. ⁵ , ⁶ , ⁷ Increasing attention has been paid to this group of patients when other risk factors, such as diabetes, are present. It may be time to focus more closely on this large group of individuals whose pressures fall below the usual criterion for treatment (>140/90 mm Hg), as defined by the sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. ⁸ The recommendations of this committee suggest that patients with persistent blood pressures of >140/90 mm Hg be considered as hypertensives. If they are in a high‐risk category, even with only minimal elevations above this level, it is recommended that they be treated pharmacologically after only short periods of lifestyle intervention. In addition, patients with stage 1 hypertension (140–160/90–100 mm Hg) but with diabetes should be treated initially with lifestyle interventions plus medications. While a blood pressure level of >140/90 mm Hg is recognized as an arbitrary cut‐off point to define hypertension, this level has been established because risk appears to increase more rapidly above this level. It is also useful to have a definition to establish treatment guidelines.

It has also been recommended that patients whose blood pressures are in the high‐normal range should be treated pharmacologically if they have diabetes or multiple other risk factors for cardiovascular disease, such as hyperlipidemia, smoking, or obesity. Some physicians believe that this represents overkill and that these patients should merely be observed. Recent data from the Framingham Study ⁴ reaffirm that in patients 35–64 years of age with high‐normal blood pressures (131–139/80–84 mm Hg), risk for cardiovascular disease is increased. This is especially true for men. This careful, prospective follow‐up study reported that the risk of a cardiovascular event for people with high‐normal blood pressure was considerably higher than in those with normal pressures (120–129/80–84 mm Hg) or those with optimal blood pressures (<120/80 mm Hg). This cohort of Framingham participants may not be representative of other populations, but the prospective study design and the large sample size underline the importance of these data.

In patients above the age of 65 with borderline elevated blood pressures, the absolute cardiovascular disease risk over 10 years exceeded the 20% risk deemed to be sufficient to warrant specific antihypertensive drug therapy. This level of risk has been defined in many international guidelines as a threshold for pharmacologic intervention. ⁹ , ¹⁰ One might conclude from these observations that elderly patients with a systolic blood pressure of 135–139 mm Hg or a diastolic pressure of 85–89 mm Hg should be treated with medication.

What Should Physcians Do About High‐Normal Blood Pressure?

Faced with the information that 1) cardiovascular risk increases with increasing blood pressures from <120/80 mm Hg; 2) data suggesting that people with high‐normal blood pressures may also have other evidence of cardiovascular involvement in the heart and vascular tree; and 3) studies define absolute and relative risk for cardiovascular disease according to blood pressure categories used in usual practice, what is the physician to do with people with just a “touch” of elevated pressure?

At present, there are no clinical trials addressing the treatment of these patients. It may be years before results of treatment are available, or we may never have such data from a long‐term, randomized trial. In view of recent information, however, on the level of risk, it may be prudent to attempt to lower the blood pressures, at least in some of these individuals, if it can be done at reasonable cost, without interfering with enjoyment of life, and without producing anxiety. Obviously, nonpharmacologic therapy, such as weight loss if appropriate, sodium restriction, moderation of alcohol, and moderate exercise should be the cornerstone of any treatment in these patients. One can expect a higher response rate in the high‐normal subjects than in patients with more severe elevations of blood pressure. Weight loss and even moderate sodium restriction should be prime targets of any intervention.

But what to do if these are ineffective and blood pressures remain in the high‐normal range? At present, definitive direction cannot be given. It would appear logical, in patients with diabetes or evidence of renal disease, such as microproteinuria, and patients with evidence of cardiac disease, that medication be given to lower blood pressure if possible. The use of a small dose of a diuretic or small doses of a diuretic/β blocker, diuretic/angiotensin‐converting enzyme inhibitor, or diuretic/angiotensin II receptor blocker might prove effective. ¹¹ Generally, side effects from this type of therapy are minimal. Only two to three visits to a physician per year are necessary. Diagnostic studies are minimal. Lowering the pressure may be accomplished without interference with life, significant cost, or inconvenience. Importantly, the program should be undertaken in a manner that does not produce anxiety.

In many cases, lowering blood pressure in people with high‐normal levels may not be necessary. Thus, many people may be treated who might do well without specific medical therapy. The new data suggest a risk level, however, that at least in older people indicates the need to lower blood pressure, especially in men.

As we move toward newer definitions of risk and newer approaches to treatment, a “touch of high blood pressure” may indicate that something should be done. Certainly, lifestyle interventions are clearly indicated.

A final note—the Framingham data are based on casual blood pressures measured in an office or clinic. The definitions of optimal (<120/80 mm Hg), normal (121–129/81–84 mm Hg), and high‐normal (130–139/85–89 mm Hg) blood pressures are not based on home blood pressures or ambulatory monitoring. It may well be that data gathered from other sources may be of equal or more importance than the casual office or clinic blood pressures, but at the moment the clinician need not be concerned about this. The correlation between office or clinic blood pressures and prognosis, or between outcome and treatment, are sufficiently well documented to warrant using these pressures as determinants of management. ¹²

Although it is advised in the treatment of patients with established hypertension that goal blood pressures be <140/90 mm Hg, many clinicians recognize that blood pressure should be lowered to as close to 120/80 mm Hg as possible in all patients, regardless of age. While this may not be possible in many older patients, it nevertheless should be a goal of treatment, especially in patients with renal disease, diabetes, and multiple other risk factors for cardiovascular disease.

A word of caution—despite these comments and concerns about high blood pressures, we should be careful about recommending treatment for additional millions of people who may be at some increased risk but whose absolute individual risk is not great. There are certainly enough “worried well” who are already overly concerned about their cardiac health. However, if people in this large group are selected carefully (elderly, other risk factors, etc.) and are treated appropriately in as simple, cost‐effective, and nonthreatening a manner as possible, cardiovascular events may be reduced still further.