L-Arginine is required for endogenous up-regulation of nitric oxide (NO), for the protection of cardiovascular implants. This study aimed to investigate L-arginine methyl ester (L-AME), an L-arginine analogue, as a novel anti-thrombogenic agent in the absence of a functional endothelium. L-AME was therefore incorporated into polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane (POSS-PCU), a material widely applied for the fabrication of surgical implants, with a focus upon the effect of L-AME on the material's physicochemical properties, and its haemocompatibility, with the aim of wider application of L-AME in cardiovascular implants. L-AME incorporated into POSS-PCU was subject to tensile strength testing, and L-AME elution rate testing; surface characterisation through contact angle measurements, Fourier-transform infrared spectroscopy, the Kaiser test, Time-of-Flight secondary ion mass spectrometry, confocal and scanning electron microscopy; and haemocompatibility was determined through thromboelastography and platelet morphology examination. Successful, uniform incorporation of increasing concentration of L-AME was confirmed through surface analysis. The tensile strength of the highest concentration of L-AME-POSS-PCU (1.05 M) was 42.7 MPa (POSS-PCU control was 66.6 MPa). L-AME incorporation produced a hydrophilic (the contact angle for the 1.05 M incorporated L-AME was 70.07 ∘ , p < 0.001), porous structure (with pore diameter of 1.90 μm at 6.915 x10 4 mm −2 for 1.05 M L-AME). Isolated L-AME exhibited anti-thrombogenic characteristics (p < 0.045), which was replicated when L-AME was incorporated into POSS-PCU (p < 0.012). L-AME demonstrated anti-thrombogenic properties and was successfully incorporated into POSS-PCU. L-AME can potentially be applied to a range of materials to confer haemocompatibility, and L-AME-POSS-PCU in the development of a range of cardiovascular implants. Recent interest has focused on the role of the methyl-arginines, endogenous inhibitors of nitric oxide, as adverse prognostic indicators. We aimed to determine the relationship, if any, of Symmetric dimethyl-arginine (SDMA) to (1) all-cause mortality and 2) disease severity as assessed by the ankle brachial index (ABI) in patients with symptomatic peripheral arterial disease (PAD). In 238 patients with symptomatic PAD and an ABI less than 0.8, L-arginine, SDMA and ADMA (asymmetrical dimethylargine) levels were measured by hydrophilic-interaction liquid chromatography-electrospray tandem mass spectrometry. The median (range) follow-up was 6 years 11 months (4 years 5 months -7 years 10 months). SDMA and ADMA levels were higher in those who died compared to those who survived (0.51 (0.44-0.66) versus 0.46 (0.39-0.55); p = <0.001 and 0.48 (0.41-0.55) versus 0.45 (0.39-0.50), p = 0.007, respectively). L-arginine levels were similar in the two groups. On multivariate analysis, SDMA and ADMA as continuous variable were significantly associated with mortality (p = 0.001). For SDMA and ADMA the highest compared to the lowest quar...