l -Arginine Can Enhance the Beneficial Effect of Losartan in Patients with Chronic Aortic Regurgitation and Isolated Systolic Hypertension.

Information about the effects of angiotensin II receptor blocker (ARB) therapy on the hemodynamic and cardiac structure in patients with chronic aortic regurgitation (CAR) and isolated systolic hypertension (ISH) is limited. This study planned to test the hypothesis that l -arginine could further enhance the beneficial effect of an ARB, losartan, and provide a favorable effect on the natural history of CAR and ISH. Sixty patients with CAR and ISH were enrolled in a randomized, double-blind trial comparing hemodynamic and ultrasonic change in two treatment arms: losartan +  l -arginine and losartan-only treated groups. Serial echocardiographic and hemodynamic studies were evaluated before and after treatment. Both groups had a significant reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP), left ventricular end-diastolic volume index (LVEDVI), LV end-systolic volume index (LVESVI), LV mass index (LVMI), and LV mean wall stress after 6- and 12-month treatment ( <0.01 in all comparisons). Both groups had a significant increase in LV ejection fraction and exercise duration after 6- and 12-month treatment (  < 0.01 in all comparisons). Using multivariate linear regression analysis, only losartan +  l -arginine therapy achieved a significantly lower LVESVI (38.89 ± 0.23 mL/m ), LVEDVI (102.3 ± 0.3 mL/m ), LVMI (107.6 ± 0.3 g/m ), SBP (123.5 ± 1.0 mm Hg), and greater exercise duration (7.38 ± 0.02 minutes) than those of the losartan-only treated groups ( <0.01 in all comparisons). These findings suggest that early co-administrative strategy provides a beneficial approach to favorably influence the natural history of CAR.