Effects of atenolol and diltiazem-SR on exercise and pressure load in hypertensive patients

Use of 24-h ambulatory blood pressure monitoring to assess blood pressure control: a comparison of olmesartan medoxomil and amlodipine besylate

OBJECTIVE

Olmesartan medoxomil is an angiotensin II receptor blocker with similar antihypertensive efficacy as the calcium channel blocker amlodipine besylate in patients with mild-to-moderate hypertension. In addition to a drug's ability to lower blood pressure, the effectiveness of the agent in enabling patients to achieve specific blood pressure targets is an important clinical consideration. This secondary analysis of a randomized, double-blind study compared the efficacy of olmesartan medoxomil with that of amlodipine besylate in achieving ambulatory blood pressure goals among patients with mild-to-moderate hypertension.

METHODS

Following a 4-week placebo run-in, 440 study participants aged >or=18 years were randomized to olmesartan medoxomil (20 mg/day), amlodipine besylate (5 mg/day), or placebo for 8 weeks. The proportion of participants achieving specific systolic and diastolic ambulatory blood pressure goal levels was calculated by dividing the number of participants who had achieved a particular blood pressure goal by the total number of patients in the intent-to-treat population.

RESULTS

After 8 weeks of treatment, a mean 24-h ambulatory blood pressure of <130/80 or <130/85 mmHg was achieved by significantly more participants in the olmesartan medoxomil group (18.1 and 30.4%, respectively) than in the amlodipine besylate (7.0 and 14.0%, respectively) or placebo (1.9% for both) groups. The target daytime ambulatory blood pressure of <135/85 mmHg was achieved by more participants in the olmesartan medoxomil group than in the amlodipine besylate group (15.8 vs. 5.8%, respectively; P<0.01).

CONCLUSION

In a previous publication of the same study, we demonstrated that starting doses of olmesartan medoxomil and amlodipine besylate produced similar mean reductions in blood pressure. In this subanalysis of the blood pressure data from that primary publication, however, olmesartan medoxomil therapy was shown to result in a greater proportion of patients achieving specific ambulatory blood pressure goals than therapy with amlodipine besylate. As blood pressure goal attainment may be of more direct clinical relevance than numerical blood pressure lowering, the achievement of blood pressure goals should be a key efficacy parameter assessed in clinical trials of antihypertensive medications.

Has the role of calcium channel blockers in treating hypertension finally been defined?

Several large, prospective, randomized, clinical outcome trials have shown that calcium channel blockers are effective and safe antihypertensive drugs compared with placebo and reduce the cardiovascular morbidity and mortality of treated patients. In other studies, when compared with conventional antihypertensive drugs, they demonstrated similar blood pressure-lowering effects and similar reductions in cardiovascular morbidity and mortality, with the exception of a higher incidence of heart failure and fatal myocardial infarction in some studies. However, considering all the evidence available today, these drugs should be considered safe for the treatment of the uncomplicated hypertensive patient in combination with other drugs. They can also be used as first-line therapy for older, stroke-prone hypertensive patients. In addition, when a calcium channel blocker is indicated for better blood pressure control, its use should not be withheld for safety concerns.

Treatment of white coat hypertension

White coat hypertension has been defined as the persistent elevation of blood pressure at the clinic or office only. It usually implies that daily ambulatory blood pressure is normal. The accepted cutoff for normal daytime ambulatory blood pressure is 135/85 mm Hg. The prevalence of white coat hypertension is high and varies from 20% to 45%. It appears to be more frequent in women, older patients, and persons with mild hypertension. White coat hypertension should not be confused with the white coat effect. The white coat effect signifies the difference in blood pressure between the office and daytime ambulatory blood pressure and occurs in patients with white coat hypertension as well as in patients with sustained hypertension that is treated or untreated. White coat hypertension is a benign condition, and the incidence of target-organ damage or cardiovascular morbidity and death is not significantly different from that in normotensive persons. Pharmacologic treatment should be withheld; instead, treatment should consist of lifestyle modification, moderate salt restriction, weight reduction, regular exercise, smoking cessation, and correction of glucose and lipid abnormalities. In addition, semiannual or annual follow-up with ambulatory blood pressure monitoring is advised.