Starting Hypertension Treatment
Setting Targets
Guidelines on when to start antihypertensive treatment have been published recently. The Sixth Joint National Committee on the Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC VI) and the World Health Organization — International Society of Hypertension have provided very similar criteria to assist decision making. Table Risk Stratification and Treatment presents the JNC VI recommendations.
The concept is relatively straightforward. Milder forms of hypertension, in patients who do not have other risk factors or evidence of target organ damage, can be managed simply by observation or by institution of lifestyle modifications for 6-12 mo. On the other hand, more severe forms of hypertension, or the presence of other important risk factors or target organ involvement, mandate early prescription of medications. The recommendations shown in Table Risk Stratification and Treatment are based partly on the results of clinical end point trials in hypertension, and partly on the opinions of experts in the field. Under these circumstances, the recommendations cannot be regarded as ironclad: there is room for judgment and discretion in clinical decision making. In reality, however,because concomitant risk factors are so common in people with hypertension, the majority of patients whose blood pressures are consistently 140/90 mmHg or higher are likely to require active treatment.
Table Risk Stratification and Treatment
| blood pressure stages (mmHg) | Risk group | ||
| (A)
No risk factors; no target organ damage/CCD |
(B)
At least one risk factor, not including diabetes mellitus; no target organ damage/CCD |
(C)
target organ damage/CCD and/or diabetes, with or without other risk factors |
|
| High normal (130-139/85-89) | Lifestyle modification | Lifestyle modification | Drug therapy” |
| Stage 1 (140-150/90-99) | Lifestyle modification | Lifestyle modification | Drug therapy |
| Stages 2 and 3 (al60/al00) | Drug therapy | Drug therapy | Drug therapy |
Adapted from JNC VI with permission.
“A patient with diabetes and a blood pressure of 142/94 mmHg plus left ventricular hypertrophy (Left ventricular hypertrophy) should be classified as having stage 1 hypertension with target organ damage (Left ventricular hypertrophy) and with another major risk factor (diabetes). This patient would be categorized as stage 1, risk group С and recommended for immediate initiation of pharmacologic treatment. Lifestyle modification should be adjunctive therapy for all patients recommended for pharmacologic therapy.
‘target organ damage/CCD, target organ damage/clinical cardiovascular disease.
Tor patients with multiple risk factors, clinicians should consider drugs as initial therapy plus lifestyle modifications.
dFor those with heart failure or renal disease or diabetes.
Are lifestyle modifications worth pursuing?
Virtually all physicians, as well as the majority of laypeople, know that losing weight or reducing salt intake is helpful in managing hypertension. But most attempts at lifestyle modification are perfunctory, and there remains considerable skepticism about these nonpharmacologic strategies.
In fairness, a critical attitude is justified. In an era of so-called evidence-based medicine, there are few if any data to indicate that lifestyle modifications actually prevent major clinical events or improve survival in hypertensive patients. Another problem is one of practicality. It is truly difficult to achieve and especially to maintain weight loss, and in contemporary times, when so many meals are eaten away from the traditional family setting, it is challenging to adhere to meaningful changes in diet. For this reason, most patients who are told to lose weight or to make other lifestyle changes will be relatively unsuccessful.
Worse yet, when the physician is then compelled to prescribe medications to control blood pressure, this can be seen as a punitive response to the patient’s failure and therefore may compromise his or her commitment to the drug therapy. Some physicians have proposed an innovative alternative: start with drug therapy with the aim of controlling blood pressure effectively and rapidly; then offer the patient the opportunity of decreasing or even eliminating the drug therapy by making appropriate lifestyle changes. Regardless of how this is done, there are some important issues to consider.
Obesity
Obesity is now recognized as a cardiovascular risk factor in its own right, and is present in about half of all hypertensive patients. Obesity leads to such abnormalities as Left ventricular hypertrophy, glomerular hyperfiltration and albuminuria, lipid abnormalities, and insulin resistance. Thus, the hypertensive patient with obesity can present a multitude of problems to be addressed and monitored during treatment. Strategies that are effective in reducing weight might have the added benefits of reversing or preventing the other cardiovascular and metabolic abnormalities that accompany obesity. Although weight loss through diet is difficult to achieve and maintain, some new pharmacologic agents have become available that might facilitate successful dieting and have acceptable safety profiles during long-term administration. If effective, this type of strategy could become an important part of managing hypertension. From the blood pressure point of view, it should be remembered that even modest reductions in body weight can produce meaningful antihypertensive effects.
Reduced Sodium Intake
Reducing sodium intake is an area of continuing controversy. It is likely that effective reduction of sodium in the diet can reduce blood pressure in some patients. Unfortunately, long-term outcome studies using this strategy have not yet provided definitive data. One recent trial claimed that sodium reduction, as well as weight reduction or the combination of the two strategies, decreased cardiovascular events in elderly hypertensive patients. On the other hand, other investigators have agreed that blood pressure reductions with sodium diets, in general, are modest, and that the resulting stimulatory effects on the sympathetic and renin-angiotensin systems could be counterproductive. Clearly, more research is needed before authoritative guidelines can be issued. Potassium supplementation of the diet has also been recommended as a strategy for blood pressure reduction. There is some theoretical support for this approach, but, again, clinical end point data are lacking.
Exercise
Exercise is a strategy that is reasonably effective in reducing blood pressure. An aerobic regimen should be considered as part of the overall hypertension treatment plan. Individuals who exercise regularly are more likely to be motivated to undertake dietary changes, and hence weight loss and possibly sodium reduction may be useful dividends of this approach.
Lipid Disorders
Decreased high-density lipoprotein cholesterol and increased low-density lipoprotein cholesterol are common in hypertension. Abnormalities in lipids can be addressed, to some extent, by appropriate dietary modification. A substantial number of hypertensive patients actually meet the published criteria for treatment with the HMG CoA reductase inhibitors, and the use of these drugs — particularly because they appear to have cardiovascular primary prevention properties in appropriate patients — should be strongly considered.
Smoking
Smoking exaggerates the adverse cardiovascular effects of the other risk factors that tend to cluster in hypertension, and cessation should be a cornerstone of management.
Blood pressure targets
Factors concerning the selection of an initial pharmacologic agent for treating hypertension are dealt with elsewhere in this book. Also of interest, however, is the selection of a target blood pressure for each patient. Despite all the attention that has been directed toward effective management of the several risk factors associated with the syndrome of hypertension, it has recently become apparent that blood pressure itself should be a critical target of therapy. JNC VI, e.g., requires that blood pressure be <130/85 mmHg to be regarded as normal; to be optimal, blood pressure should be <120/ 80 mmHg. As a practical matter, the JNC VI recommends treating blood pressure to below 140/90 mmHg in most hypertensive patients, and to below 130/85 mmHg in patients with concomitant conditions such as renal insufficiency or diabetes mellitus.
The Hypertension Optimal Treatment study has strongly influenced aggressive new blood pressure targets. This study examined the impact of differing degrees of blood pressure control on cardiovascular clinical outcomes. In general, best results were observed when blood pressure was reduced to the area of 130/82 mmHg. In vulnerable patients, particularly diabetic hypertensive patients, the final few blood pressure points in this range were important; for example, there were fewer events when diastolic blood pressure was reduced to 82 mmHg than when it was reduced only to the mid-80s. Two other important points were revealed by the Hypertension Optimal Treatment study. First, quality of life was highest in those patients whose blood pressures were most markedly reduced. This should help put to rest fears that intensive treatment of hypertension produces excessive side effects. Second, multiple drugs, in many cases three or more, were required to achieve the blood pressure targets. The following conclusion can be drawn: if physicians attempt to achieve aggressive blood pressure goals, they can do so in the majority of hypertensive patients, and even if this requires multiple drugs, there does not appear to be a quality of life penalty.
Similar findings have emerged from other studies. In a trial in patients with already existing renal insufficiency — admittedly a minority of hypertensive patients — optimal prevention of events was achieved at a blood pressure of approx 125/75 mmHg. Another recent study, the United Kingdom Prospective Diabetes Study, has also shown the clinical end point benefit of aggressive blood pressure reduction in hypertensive patients with diabetes. In fact, this study’s investigators claimed that reaching target blood pressure goals may be more important than the issue of which type of antihypertensive agent should be used as the basis of treatment.
One other point should be mentioned. There has been concern among some clinicians about the so-called J-curve phenomenon in which excessive reduction of diastolic blood pressure is thought to increase rather than decrease the probability of major cardiac events. The basis for this concern is that because filling of the coronary circulation occurs by backflow during diastole, excessive reduction in diastolic pressure could result in decreased blood supply to the myocardium. Several recent studies, however, have focused on whether or not there is any excess risk associated with large reductions in the diastolic blood pressure. To date, there does not appear to be evidence to suggest any particular risk with this strategy, and it seems that many more hypertensive patients are hurt by inadequate reduction in blood pressure than by excessive reduction.
How well is blood pressure being controlled?
Although the diagnosis and management of hypertension in the United States is probably better than in any other country in the world, according to the National Health and Nutrition Examination Survey, barely one quarter of hypertensive patients in the United States have their blood pressures controlled to the recommended level of 140/90 mmHg. This critical issue is discussed in greater detail elsewhere in this book. When the question arises about why we are not doing a better job of controlling blood pressure, most physicians state that they believe the problem lies with poor patient compliance. To be sure, this is a problem, and much research needs to be done to understand why hypertensive patients, who clearly are at risk of devastating strokes and other cardiovascular events, so inconsistently adhere to their treatment.
But, much of the blame also can be attributed to physicians. A recent study from the Veterans Affairs system has indicated that physicians appear to be reluctant to enforce the changes in therapy necessary to achieve optimal blood pressure control. Indeed, there appears to be a need to understand why physicians, even when the importance of effective blood pressure control is clearly understood, are so reluctant to take the necessary steps to provide the full measure of treatment that patients require.
If reaching target blood pressure goals is so important, how can it be achieved? First, it is important to prescribe drugs in their full dose. With modern drugs, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and even calcium channel blockers, maximum doses can be given in most patients without significant side effects. Second, it must be understood that achieving meaningful target blood pressure goals will require multiple drugs. Fixed combination products are sometimes a useful solution to this issue because they provide the convenience and cost savings associated with providing two drugs in one pill or capsule.
Large-scale clinical trials have shown that patients are willing to take multiple drugs to achieve goal blood pressures, particularly if they know that preventing strokes and other serious outcomes is the real objective of treatment. It should also be acknowledged that there are patients whose blood pressures are truly difficult to control. New types of pharmacologic agents will be an important answer to this problem, and physicians must continue to encourage development of new therapies that will allow the achievement of effective care for all hypertensive patients.
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