Q: Many of my patients appear to have white-coat hypertension: their pressure is elevated when measured in my office—but normal when measured at home. Am I ignoring significant hypertension if I do not treat these patients? Or am I overtreating if I do treat?
A: Most patients have lower blood pressure (BP) at home than in the physician's office. Measurements taken with ambulatory BP instruments are lower than office readings by about 10 mm Hg. My recommendation is to target treatment to office BP measurements. Office readings should be below 140/90 mm Hg in healthy adults, and below 135/85 to 130/80 mm Hg in adults with diabetes. Take time to measure BP correctly: for example, measurement should be done after the patient has been sitting for 5 minutes—not after he or she has just bolted up the steps.
A significant discrepancy (that is, 8 to 10 mm Hg) between office and home BPs is cause for concern. But the office measurement is what counts for most patients: all clinical trials, therapy benefits, epidemiologic reports, and risk calculations are based on those numbers. Newer studies show that ambulatory BP may better reflect target organ damage; however, we do not have a significant number of studies in which ambulatory BP was tied to clinical outcomes such as stroke.
In rare cases, there is a dramatic difference between office and home BPs (for example, systolic pressure of 170 mm Hg in the office and 110 or 120 mm Hg at home). For such a patient, ambulatory BP measurement is particularly useful. Home BP instruments are not uniformly reliable, however. If a patient needs or wants to take BP measurements at home, have him bring the machine to the office so it can be calibrated.
Q: Should I treat a patient whose office BP is only mildly elevated, say 144 or 148 mm Hg over 70 or 80 mm Hg, if his home systolic pressure is 130 mm Hg?
A: The treatment of patients with hypertension should be based on global risk rather than BP level alone. The goal of antihypertensive therapy is not simply to lower BP but to prevent morbidity and mortality. When a patient has what appears to be mildly elevated BP, consider ambulatory BP monitoring or look for evidence of target organ damage. If echocardiography shows left ventricular hypertrophy or if the patient has microalbuminuria, I would recommend antihypertensive therapy. If the patient has no comorbidities, I would be less inclined to treat.
It is unlikely that we will ever have hard clinical data that clearly show the benefits of treating patients with mildly elevated pressures. I don't foresee a clinical trial that compares outcomes in normotensive patients with those who have mild hypertension and no other risk factors. However, a growing body of evidence indicates the need to treat patients with mildly elevated BP who have an additional risk factor, such as diabetes.
Q: For which patients with elevated BP should I consider a trial of diet and exercise—and for how long?
A: The most important nonpharmacologic measures are weight loss and sodium reduction. A low-fat, low-sodium diet such as the DASH diet is beneficial.1 However, if systolic pressure is high—for example, 160 or 170 mm Hg—it is unlikely that nondrug therapy alone will make the patient normotensive. In this setting, a recommendation that a patient lose weight and return to your office in 6 months is not advisable.
On the other hand, if a patient has stage 1 isolated systolic hypertension—that is, pressures of 140 to 150 mm Hg—a 3- to 6-month nondrug therapy trial may be appropriate, just as it would be for a patient with diastolic hypertension. In this situation, however, the patient needs to be closely followed. If you don't see the patient for several months, his BP may have risen significantly. Furthermore, adherence to nonpharmacologic therapy programs depends in large measure on frequent contact between the patient and clinician.
Q: Many of my patients have a hard time complying with nonpharmacologic strategies. What do you suggest?
A: Compliance success—or failure—depends on the particular patient and on how the strategy is implemented. In general, long-term weightloss programs are more successful if dietary change is associated with an exercise program and with social support and encouragement. The Trial of Nonpharmacologic Interventions in the Elderly (TONE) investigators found that after BP had been controlled for 1 year, antihypertensive medication could be safely withdrawn in persons aged 60 to 80 years whose BP was 150/90 mm Hg or lower and who had no clinical evidence of cardiovascular disease—provided that good BP control could be maintained with nonpharmacologic therapy.2 Patients were very compliant. Moreover, patients in the combined weight loss/sodium reduction group had a 53% lower chance of remaining free of a trial end point (sustained BP of 150/90 mm Hg or higher, a clinical cardiovascular event, or a decision to resume BP medication) for the duration of the study compared with patients in the usual-care group.
However, this study was unusual in that patients met with dietitians frequently. These dietitians went shopping with patients, taught them how to buy the right food, how to read lists of ingredients, and even how to cook.
Q:Is there an age beyond which patients no longer benefit from antihypertensive therapy?
A: Current guidelines advise against an age-specific cutoff and recommend continuing to treat even very elderly hypertensive patients.3 Some epidemiologic data show that in persons 90 years or older who are not being treated there is no absolute proof of incremental risk of stroke, heart disease, and mortality with increasing BP. This issue is being investigated in the Hypertension in the Very Elderly Trial (HYVET)—an international study now under way that is evaluating the effect of antihypertensive therapy on incidence of stroke and cognitive function in patients 80 years and older.4
On the other hand, in clinical trials such as the Systolic Hypertension in the Elderly Program (SHEP)—where we enrolled persons 60 years and older, with no upper age limit—there was no decrease in benefit for older people.5
Q: Many of my colleagues are turning to angiotensinconverting enzyme (ACE) inhibitors as first-line therapy for elderly patients with isolated systolic hypertension. Is there convincing evidence for such a practice?
A: ACE inhibitors have been shown to decrease cardiovascular events among patients at high risk with and without hypertension. However, these agents are not recommended as firstline therapy for isolated systolic hypertension in the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI). This is because in controlled clinical trials of older persons with this condition, only 2 classes of drugs were more effective than placebo: diuretics—such as chlorthalidone—and long-acting calcium channel blockers (CCBs)—such as nitrendipine(Drug information on nitrendipine).5,6 The JNC VI guidelines therefore recommend diuretics ("preferred" agents) or long-acting dihydropyridines.3
A low-dose diuretic—a thiazide or thiazidelike agent—at a dosage of 12.5 to 25 mg/d is an easy and cost-effective way to initiate antihypertensive therapy. Elderly patients may need additional pharmacotherapy related or unrelated to their BP— such as an ACE inhibitor for heart failure or a β-blocker or CCB for angina. The results of trials such as this argue against an agespecific treatment cutoff.