Hypertension research : official journal of the Japanese Society of Hypertension
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Randomized Controlled Trial Comparative Study
Rationale, design and patient baseline characteristics of OlmeSartan and calcium antagonists randomized (OSCAR) study: a study comparing the incidence of cardiovascular events between high-dose angiotensin II receptor blocker (ARB) monotherapy and combination therapy of ARB with calcium channel blocker in Japanese elderly high-risk hypertensive patients (ClinicalTrials. gov no. NCT00134160).
Higher doses of angiotensin II receptor blockers (ARBs) are expected to exert more protective effects against cardiovascular diseases. However, the significance of treatment of hypertension with high-dose ARB remains to be defined. The OlmeSartan and Calcium Antagonists Randomized (OSCAR) Study was designed to determine whether high-dose ARB monotherapy is superior to the combination therapy of ARB plus calcium channel blocker (CCB) in the prevention of cardiovascular morbidity/mortality in Japanese elderly high-risk hypertensive patients. ⋯ The primary end points will be the composite of fatal and non-fatal cardiovascular events, and death from any cause. Recruitment for the OSCAR study (around 1200 patients) was completed by the end of May 2007. The OSCAR study is the first large clinical trial comparing the efficacy of high-dose ARB monotherapy with that of an ARB plus CCB combination therapy in elderly high-risk hypertensive patients.
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Hypertensive patients with obstructive sleep apnea syndrome (OSAS) constitute a high-risk group for metabolic syndrome. OSAS directly induces negative intrathoracic pressure and decreases pulmonary stretch receptor stimulation, chemoreceptor stimulation, hypoxemia, hypercapnia and microarousal. These changes potentiate various risk factors, including the sympathetic nervous system, renin-angiotensin-aldosterone system and inflammation. ⋯ Continuous positive airway pressure (CPAP) therapy, a first-line treatment in hypertensive patients with moderate to severe OSAS, reduces ambulatory BP level, particularly during the sleep period, and midnight BP surge. However, individual differences in the BP-lowering effect of CPAP have been observed. OSAS hypertensive patients who do not tolerate CPAP remain at a high risk for cardiovascular disease because of negative intrathoracic pressure and need more aggressive antihypertensive treatment to achieve 24-h BP control with nocturnal BP <120/70 mm Hg.