Background: L-arginine, the precursor of nitric oxide, may restore nitric oxide levels and bioavailability and influence symptom severity, quality of life (QoL), physical performance, and left ventricular (LV) diastolic abnormalities in patients with chronic systolic heart failure (HF). The aim was to evaluate the effects of orally administered L-arginine in chronic HF patients.
Material/methods: A parallel double-blind multicenter randomized study was performed in 68 patients (mean age: 64+/-11 years) with mild-to-moderate systolic HF (NYHA class II-III) and LV ejection fraction (EF) <or=45%. They were randomly allocated to two groups: 2 g tid of L-arginine (n=37) or placebo (n=31) were administered orally for 3 months. QoL score was evaluated by the Minnesota Living with HF Questionnaire (MLWHFQ). A complete Doppler and echocardiographic study was performed in all patients, including measurement of the E: A ratio and E-wave deceleration time (EDT). An EDT <150 msec identified patients with restrictive mitral flow. Mean LV EF at baseline was 31+/-7%.
Results: The mean difference in MLWHFQ score from baseline was -9.7 in the L-arginine (95%CI: -14.6, -4.7) and -4.2 in the placebo group (95%CI: -8.9, +0.55). The difference between groups was not statistically significant. Among the patients with advanced LV diastolic dysfunction, 7 of 9 in the L-arginine and 3 of 6 in the placebo group showed reversible restrictive mitral flow after therapy.
Conclusions: Although no significant difference in QoL score was found between L-arginine and placebo, the results showed that L-arginine significantly improved QoL from baseline, in contrast to placebo, in chronic HF patients.