Although many reports show that ACE inhibitors and angiotensin II receptor blockers (ARB) are superior for prevention of cardiovascular events, previous data are not enough for the patients who have more than one risk factor and for anti-atherosclerotic effects of ARB. In Japan, there were only a few large-scale trials for cardiovascular disease prevention, and it has not been clarified whether the evidence in Western countries could be unqualifiedly applied to Japanese patients as a long-range strategy. The KYOTO HEART Study is to assess the add-on effect of valsartan, an Angiotensin-Receptor Blocker, on top of the conventional treatment in high risk patients with hypertension in terms of the morbidity and mortality.