Implantable cardiovascular devices have revolutionized the treatment of cardiovascular diseases, yet their long-term functionality without causing thrombosis is a persistent challenge. Although the surface modification of anticoagulant coating has greatly improved the biocompatibility of the devices, its long-term stability in complex physiological environments still remains questionable. Herein, the stability of three anticoagulant hydrogel coatings, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), poly(sodium 2-acryloyl-2-methylpropanesulfonate) (PAMPS), and poly(4-styrenesulfonate sodium) (PSS), is studied. The fabrication of these coatings onto device surfaces is validated by using X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. In vitro anticoagulation assays confirm the coatings' significant anticoagulant effects. Among all three coatings, the PSS coating demonstrated superior chemical and mechanical stability in the comprehensive tests, showing great potential for improving the long-term anticoagulant performance of implantable cardiovascular devices.