Angiotensin receptor blockers in hypertension. New insights from Japan.

Angiotensin II receptor blockers (ARBs) are widely used in the treatment of patients with hypertension, heart failure, diabetic nephropathy and other clinical conditions. Several intervention trials and systematic overviews showed that both angiotensin-converting enzyme inhibitors and ARBs effectively reduce the risk of stroke, myocardial infarction and congestive heart failure in hypertensive patients. Two recent intervention trials conducted in Japan (JIKEI and Kyoto studies) suggested that the protective effect of ARBs on major cardiovascular events might be partly independent from the degree of blood pressure (BP) reduction. Both studies used a prospective randomized open blinded end point (PROBE) design. No significant differences emerged in both studies between the ARB group (valsartan) and the control group in the achieved BP. We made a pooled analysis of the JIKEI and Kyoto studies. Overall, valsartan significantly reduced the risk of the primary composite outcome (by 42\%; P<0.0001), angina pectoris (by 38\%; P<0.0001), heart failure requiring hospitalization (by 43\%; P=0.013) and cerebrovascular events (by 42\%; P=0.002). The protective effect on the dissecting aneurysm of aorta bordered statistical significance. These data reinforce the notion that the protective effect of angiotensin II inhibition is partly independent of BP reduction.