Short-term evaluation of thromboresistance of a poly(ether ether ketone) (PEEK) mechanical heart valve with poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted surface in a porcine aortic valve replacement model.

Improved thromboresistance of mechanical valves is desired to decrease the risk of thromboembolism and thrombosis and reduce the dosage of anticoagulation with a vitamin K antagonist (e.g., warfarin). For several mechanical valves, design-related features are responsible for their improved thromboresistance. However, it remains unclear whether material-related features provide a practical level of thromboresistance to mechanical valves. Here, we studied the effect of a bileaflet valve made of poly(ether ether ketone) (PEEK) with a poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted surface (PEEK-g-PMPC). PMPC is a well-known thromboresistant polymeric material. A short-term (<26 h) porcine aortic valve replacement model using neither an anticoagulant nor an antiplatelet agent showed that the PEEK-g-PMPC valve opened and closed normally with an allowable transvalvular gradient. Unlike an untreated PEEK valve, no thrombus formed on the PEEK-g-PMPC valves on gross anatomy examination in addition to the absence of traveled thrombi in the kidney and lung tissues. Material (PEEK-g-PMPC)-related thromboresistance appeared to decrease the risk of thromboembolism and thrombosis for patients with mechanical valves. However, thromboresistance of the PEEK-g-PMPC valve requires improvement because fibrous fouling was still observed on the leaflet. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1052-1063, 2019.