valsartan in elderly isolated systolic hypertension (VALISH) study: rationale and design.

Although antihypertensive therapy has been proven to reduce cardiovascular morbidity and mortality, it is unclear how much blood pressure should be decreased in elderly patients with hypertension. The Valsartan in Elderly Isolated Systolic Hypertension (VALISH) study is a multicenter parallel-group study comparing the incidence of cardiovascular events between two target systolic blood pressure levels, below 140 mmHg and below 150 mmHg, under treatment with valsartan, an angiotensin II receptor blocker, as an initial antihypertensive drug in elderly patients with isolated systolic hypertension. The number of patients to be recruited is 3,000 and the duration of follow-up is at least 2 years. This 3,000-patient trial was designed with a two-sided alpha level of 0.05 and 80% power to detect the difference in incidence of cardiovascular events between the target blood pressure levels based on estimation of the cardiovascular events ratio as 21.5/1,000 patient-years and 29.1/1,000 patient-years for the two blood pressure levels. The VALISH study, a large-scale investigator-initiated trial in Japan, will determine whether age should be considered in setting target blood pressure in treatment of isolated systolic hypertension in elderly patients.