Hypertension affects approximately 50 million individuals in the United States. As the population ages, the prevalence of hypertension will continue to increase if broad and effective preventive measures are not implemented. According to the World Health Organization, hypertension is the most common attributable cause of preventable death in developed nations, as uncontrolled hypertension greatly increases the risk of cardiovascular disease, cerebrovascular disease, and renal failure. Despite the availability of antihypertensive treatments, hypertension remains inadequately controlled; only about one third of patients continue to maintain control successfully.~A major component of blood pressure regulation is the renin-angiotensin-aldosterone system, a system of hormone-mediated feedback interactions that results in the relaxation or constriction of blood vessels in response to various stimuli. Angiotensin II, a polypeptide hormone, is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme as part of the renin-angiotensin-aldosterone system. Angiotensin II is the principal pressor agent of the renin-angiotensin-aldosterone system with a myriad of effects on the cardiovascular system and on electrolyte homeostasis.~In the United States, a disproportionate number of African-Americans have hypertension compared to age-matched non-Hispanic Caucasians and Mexican Americans. Earlier onset and greater severity of hypertension in African-Americans contribute to greater target organ damage and may be a factor in shorter life expectancy in this population compared to Caucasian-Americans. Although genetic factors have been invoked to explain these racial differences, environmental factors probably play a more important role. Improved management of hypertension through both lifestyle intervention and pharmacotherapy, including combination therapy, are necessary to achieve target blood pressure in African Americans.~Takeda Global Research & Development Center, Inc. is developing TAK-491 (azilsartan medoxomil) to treat patients with essential hypertension. Azilsartan medoxomil is a prodrug that is hydrolyzed to the active moiety, TAK-536 (azilsartan), which is a selective antagonist of the angiotensin II type 1 receptor subtype.~This study is being conducted to evaluate the effectiveness and safety of oral azilsartan medoxomil compared with placebo in African-American participants with essential hypertension. Participation in this study is anticipated to be approximately 10 weeks.
The purpose of this study is to evaluate the effectiveness and safety of azilsartan medoxomil compared to placebo, once daily (QD), in African-American participants with essential hypertension.