Background: The effect of L-arginine and L-citrulline on blood pressure and right ventricular function in heart failure patients with preserved ejection fraction (HFpEF) is unknown. We have therefore evaluated, in a randomized clinical trial, the effect of these aminoacids in chronic outstanding and stable patients with HFpEF.
Methods and results: All patients underwent an echocardiogram and radioisotopic ventriculography rest/exercise, and were randomized in a consecutive manner to the L-arginine group (n = 15; 8 g/day); and the citrulline malate group (n = 15; 3 g/day). The duration of follow-up was two months. The principal echocardiographic finding was a statistically significant decrease in pulmonary artery pressure in the L-arginine (56.3 ± 10 vs 44 ± 16.5 mm Hg, p < 0.05) and the citrulline (56.67 ± 7.96 vs 47.67 ± 8.59 mm Hg, p < 0.05) groups. Duration on treadmill and right ventricular ejection fraction post exercise increased, while diastolic and systolic artery pressure decreased significantly in both groups. There were no other statistically significant differences between the groups.
Conclusions: Administration of L-arginine and citrulline to patients with HFpEF improved right ventricular function by increasing right ventricular ejection fraction, and probably decreasing systolic pulmonary artery pressure.