The main advantage of antihypertensive therapy with telmisartan is its strong inhibition of plasma aldosterone concentration

BaCKgrouNd: The elevation of the plasma aldosterone concentration during the long-term inhibition of the renin-angiotensin system is known as the aldosterone breakthrough, and it may be attributable to organ damage in the heart, kidneys and other organs. Telmisartan inhibited cardiac fibrosis and suppressed the increase in the plasma aldosterone concentration independent of blood pressure in our animal model of renovascular hypertension. oBjeCtives: To prospectively investigate whether the aldosterone breakthrough occurrs during antihypertensive therapy with telmisartan or perindopril. Methods: Forty-two outpatients who had inadequately controlled blood pressure were enrolled in the present study and 40 mg/day telmisartan or 4 mg/day perindopril was appled to these outpatients for 48 weeks. results: Systolic and diastolic blood pressures were significantly decreased during 48 weeks of antihypertensive therapy, but there were no significant differences in these blood pressure values between the telmisartan and perindopril treatments. The plasma aldosterone concentrations gradually decreased and remained at a low level in the telmisartan group (−16%; from 116.3±11.1 pg/mL to 97.5±9.6 pg/mL), but only transiently decreased (−18%; from 120.2±16.0 pg/mL to 98.1±9.6 pg/mL) then returned to the control level (114.5±12.4 pg/mL) in the perindopril group. Additionally, the plasma renin activities and the plasma angiotensin II concentration were changed as the compatible kinetics of these plasma aldosterone concentrations. CoNClutioNs: The results of the present study show that the aldoster one breakthrough during the long-term inhibition of the renin-angiotensin system by telmisartan was not observed, and maintaining the plasma aldosterone concentration at a lower level using telmisartan may be an advantage in the control of organ damage by aldosterone compared with perindopril.